Note that the three amplifier cathodes are tied together on the right side of C135, to form the matrix from X and Z to R-Y, G-Y, and B-Y. Therefore, you have a mixed waveform at that point, which is not the opposite of the three different waveforms on the CRT grids. This is because each amplifier has a different waveform on its grid.

The waveform on the CRT grid will be approximately the opposite of the associated amplifier grid, but somewhat different due to the matrixing.

The G-Y amp has only DC on its grid, and therefore the green CRT grid will be the same polarity as the voltage on the common amplifier cathodes (but amplified).

So, what you will see on the right side of C135 is actually a G-Y signal.

Note that there is a large negative blanking pulse connected to the amplifier cathodes, so this negative pulse appears on the CRT grids also. This is easiest to see on the green CRT grid.

Note that the three amplifier cathodes are tied together on the right side of C135, to form the matrix from X and Z to R-Y, G-Y, and B-Y. Therefore, you have a mixed waveform at that point, which is not the opposite of the three different waveforms on the CRT grids. This is because each amplifier has a different waveform on its grid.

The waveform on the CRT grid will be approximately the opposite of the associated amplifier grid, but somewhat different due to the matrixing.

The G-Y amp has only DC on its grid, and therefore the green CRT grid will be the same polarity as the voltage on the common amplifier cathodes (but amplified).

So, what you will see on the right side of C135 is actually a G-Y signal.

Note that there is a large negative blanking pulse connected to the amplifier cathodes, so this negative pulse appears on the CRT grids also. This is easiest to see on the green CRT grid.

once i put the new resistors in.
It is that large negative pulse that I'll scope out first , pin 1 v21, though i doubt it, c135 may be flaky.

Well that sucks, the SK3756/NTE508 lasted for 45 sec, then burned up. :tears:
must have been bad or something cause the box it came in has an insert saying , replaces 3CA3.
put old fashion one back for now. :/

Is it even worth trying again with another SK3756/NTE508 to save some the ma from the heater draw?
everything I have looked up says it should not have burned up like that :/

https://www.nteinc.com/specs/500to599/pdf/nte508thru510_514.pdf
http://www.tubebooks.org/tubedata/hb-3/receiving_tubes_part_1/3CA3.PDF

I have no experience making this replacement, but have to agree that the pinout and specs look right. NC on all the other pins means it should work even if this chassis used some of them as convenient soldering points.

still not sure what i should see on pin one of V21, voltage is still high, in ref to SAMS 147v
waveform there is about 12v ptp, not sure if this is normal.

Not following what 147 v waveform you are referring to. According to the schematic, pin 1 of V21 (V21a plate) should be at 115 v dc. Since it is coupled to the color difference amplifier cathodes by C 135, it should have the same peak to peak ac waveform as those cathodes, which the schematic shows as 15 volts peak to peak. The 12 v p-p you measure is very reasonable and the total p-p will depend also on the amount of color in the image as well as the setting of the color level control. With the color turned all the way down, you should see just the blanking pulse, which by itself appears to be 10 or 12 v p-p.

Did you mean you read 147 v DC?

Did you mean you read 147 v DC?
yes, its at 147 v DC still and when i hooked a o-scope i saw a 13 volt wave there left side of c135
Cathode @ 6v , grid @ -86v with 240v waveform


edit
r203/204 new and V21 new.

By the way, a difference of 147 vs. 115 volts could result from a 13% variation of triode characteristics, which is probably not a totally unreasonable variation from the tube in the set SAMS measured to one you might have.

[When I was in school, I pissed off the lab instructor by asking how big the variations bewteen tubes of the same type were. He apparently didn't want to admit that he didn't know either.]

yes, its at 147 v DC still and when i hooked a o-scope i saw a 13 volt wave there left side of c135
Cathode @ 6v , grid @ -86v with 240v waveform


edit
r203/204 new and V21 new.

As you are getting a good blanking pulse, my bet is that the designers expected the variation in the range you are seeing and determined that the circuit would still work properly with this variation.

Edit: if you have extra tubes, it might be educational to plug a few in and see if the DC changes but the pulse is still OK. If you don't have extras, you could still experiment by exchanging V21 and V20.

I looked up the 6GU7 data sheet and it says the plate resistance is "5500 ohms (approx)" but they don't say how approximate. Isn't that cute!

As you are getting a good blanking pulse, my bet is that the designers expected the variation in the range you are seeing and determined that the circuit would still work properly with this variation.

Edit: if you have extra tubes, it might be educational to plug a few in and see if the DC changes but the pulse is still OK. If you don't have extras, you could still experiment by exchanging V21 and V20.

Tried that, did not hep much, I do have another one ordered.

Also, it does not help much that I have things bypassed and have video fed in, so that MAY be part of it, it is weird, some times the retrace lines are seen, other times they are not, not sure why it is doing this.

Tried that, did not hep much, I do have another one ordered.

Also, it does not help much that I have things bypassed and have video fed in, so that MAY be part of it, it is weird, some times the retrace lines are seen, other times they are not, not sure why it is doing this.

Well, I guess you will need to continue poking around to see what is changing between when retrace is visible and when it is not.

Is it dependent on picture content (only shows up on dark scenes or light scenes)?

Is your video input at the first video amp grid (pin 7) the same DC and peak to peak as shown in the schematic? (0v dc and 3.5 vp-p)?

Is your video input signal DC coupled or AC coupled? The video DC coupling in these old sets is usually about 85%, which means the brightness (black level) drifts up a bit on dark scenes and down a bit on bright scenes. Two things could affect this with your external video input and make it worse:

1) If the DC level at the first video is wrong, you will get the wrong DC level at the cathodes and have to compensate it with tracking adjustments, which may make you run out of blanking headroom in certain scenes.
2) If your video input is AC coupled, the black level will drift up and down strongly depending on overall scene brightness, and in dark scenes may drift so high that you run out of blanking headroom.

Are you aware of the effects of macrovision copy protection on tube sets? That will cause retrace lines that come and go despite a set working properly.

Are you aware of the effects of macrovision copy protection on tube sets? That will cause retrace lines that come and go despite a set working properly.

i'm using a dvd that i created myself, so i know that is not an issue .

=====
Electronic M
Why not just use a .1uF cap to couple the transistor amp output to the grid?..It will block DC from changing grid bias, should couple the video just fine and RCA colors all had some form of DC restoration that negates and need for DC video coupling in the early stages of the video chain.
=======
old_tv_nut
If you use a coupling cap and remove L9, you will need to add a grid bias resistor (say, 100k) from G1 to ground.
=======

here is how it is right now,
https://imgur.com/NosUKXZ
https://imgur.com/wQj8vGR

the .1uF cap is on the amp pcb i made, the 100k resistor on the set, on the bottom of the tube.

the .1uF cap is cheap low quality, i did not think it mattered that much,
also , since it is a temp setup right now, i am using a low quality cable to to patch it over.

Would the cap be better suited on the bottom of the tube near the 100k res?
or leave it on the amp PCB and just try a better quality cap and cord?

i'm using a dvd that i created myself, so i know that is not an issue .

The video injection schematic looks good.

If you have a DTV box I'd try that to confirm. The DVD recorder/VCR and computer methods I have to create DVDs give the option to make a disc with the macrovision flag set (though they just call it copy protection or something like that). That could be set default to on in your system or you could have a DVD player that constantly outputs it. DVDs don't come encoded with macrovision and only have a flag bit that tells the DVD player to create and mix in the macrovision signal. There are some DVD players where one can easily set the machine to always neglect adding macrovision and the other way around is not impossible either.

I'm not entirely sure that is a macrovision issue or not, but it can be tested.
The videos on the test DVD were originally MKV format, and converted to DVD using Freemake Video Converter, there is no option for copy protection in the burn setting, nor region code. So it is most likely off, but can't be sure.

I do have to option of trying my Pioneer LD-V8000, this outputs pure analog video with no copy protection, and can go with helping with what I'm suspecting that this is a symptom of something else I have not found yet.

I think just to err on the side of caution, I'll replace that cheap ass .1uF cap ceramic cap of unkmown tol on the amp, with one of the better film ones I have 10%, and wire in the video cable I intended to use for the final setup and see what happens.

no change using the LD input retrace lines are still there
https://imgur.com/LCoR4sm
changing the cap and cable on my video amp did not help much.

I DID nitice something however, moving the wires to the CRT socket drastically made an effect in the screen color level.

now IDK if this means there are bad connections in the socket on the CRT, or if there is a problem with the socket itself, I DO have a brand new CRT socket, and it wont be too much effort to splice it on, but i have also read of there being problems with fractured solder on CRT pins, could it be both?

I'm not sure, but i'm willing to bet this is the cause of the retrace line problem.

Possible. I just had a 21AXP22 I wrote off for dead when I bought the set it was in come back to life...CRT heater was open, but reflowing the solder on the base pins (after I verified the tube was still under vacuum) brought it back.

Sockets can fail too. The focus contact is usually first to go beacuse the ozone the HV generates corrodes the metal faster, but no harm checking them all though.

I'm not sure what the problem is yet, but I know what it is not, I went ahead and changed the CRT socket anyway, this fixed the issue of the color changes I saw when I moved the wires around, but not the fluctuating in the blue level or the coming and going or the retrace, so just to test things , i swapped lines for the red and blue guns with each other, and the problem changed to red, telling me the CRT and pins are OK, and there is a problem with the B-Y amp or blue screen control, bad caps perhaps?
blue drive , i doubt, it has been cleaned ( deoxit ) 2 times.

I don't get it, I'm still seeing some original resistors on the color PCB, if who ever worked on it before, was replacing so many, why stop?
R181,184,189 are old, and perhaps some others in the area, I can also see that the orange drop caps near the tubes are also old, this COULD be the cause of the changes in output level I am seeing when I turn the set on and it heats up.
I will see after I go over and replace them.

Well, due to the holiday, i wont get my caps till Monday :sigh:

But i did get my solid state focus rect, and it did NOT burn up, like the HV rect did. :)

so when doing the horz output cathode current check, it is now stable at 202ma

I MAY try again with another SS HV rect, IDK.

You do know that retrace lines were always a problem with older sets and new formats like VHS, Laser disc, and DVD right? More a problem with the format than the tv. You may need to repair the IF and tuner to make them go away completely. As far as the set goes, retrace is often caused by to high CRT bias. Do a proper grey scale setup and it will help. I don't remember if the 16 had a separate crt bias control, but if it does turn it all the way down then try the grey scale adjustments of the screen controls. If one does not produce a line, then and only then turn up the crt bias just enough to get that line and reset the others.
As far as the solid state rectifiers goes, I never had much luck with them. They seemed to fail just as much as the tubes. Anytime I found one in a set, I took it out and replaced it with the tube. Remember the design engineers designed the circuit for tubes and their current draw. 202ma cathode current is still a little high. I would shoot for under 200 if possible.

You do know that retrace lines were always a problem with older sets and new formats like VHS, Laser disc, and DVD right? More a problem with the format than the tv. You may need to repair the IF and tuner to make them go away completely. As far as the set goes, retrace is often caused by to high CRT bias. Do a proper grey scale setup and it will help. I don't remember if the 16 had a separate crt bias control, but if it does turn it all the way down then try the grey scale adjustments of the screen controls. If one does not produce a line, then and only then turn up the crt bias just enough to get that line and reset the others.
As far as the solid state rectifiers goes, I never had much luck with them. They seemed to fail just as much as the tubes. Anytime I found one in a set, I took it out and replaced it with the tube. Remember the design engineers designed the circuit for tubes and their current draw. 202ma cathode current is still a little high. I would shoot for under 200 if possible.

As i mentioned, I don't have the equipment to do an IF alignment, nor have I ever done it before, so it is very unlikely that I will ever be able to undo the damage that was done to the IF section by the nut who had it before me.

The R/G/B - Y amps are sill unstable and change in output, so as soon as a grey scale setup is done, it's way off again 5-10 min later, as it warms up, still waiting for parts for that area.

I'm not too worried about the 202ma cathode current, but at this point there is little i can do about it, L40 horizontal efficiency coil has been core locked and i cant adjust it. a new one has been ordered, but the way it's running now is below the 210ma it says is the limit in the SAMs, and when I have it on, it's not on that long anyway.

R/G/B -Y amps fixed and stable. am no longer seeing retrace lines.

https://imgur.com/veMo2go

The caps were def a problem.
So now I wait for new coil, and a chance to fix the cataract.

R/G/B -Y amps fixed and stable. am no longer seeing retrace lines.

https://imgur.com/veMo2go

The caps were def a problem.
So now I wait for new coil, and a chance to fix the cataract.

Makes sense, since these amps also apply DC restoration and horizontal blanking to the grids.

For when I DO get the cataract fixed, I have seen no reference or diagrams as exactly WHERE on the neck the convergence yoke is placed, ( how far forward / back ) I can make a guess based on the markings, but, I have not seen it written anywhere that I can find, nor have I seen something for placement of purity rings or blue lateral.

Placement of them is probably not super critical, but then again, I can imagine that the placement of them a few degrees forward / back would have a visual effect. And find it a little hard to believe that there is no instructions / diagram someplace saying “this goes aprox here,” and so on.

Also, I have found the static convergence magnets quite hard to manipulate / adjust, no doubt have gotten tight over the years, any known way to make them slide easier for when final convergence is done?
Thanx.

There is a ring at the end of the electron gun the thickness of the convergence yoke that is closer to the glass then the rest of the gun....put the convergence yoke there. Place purity behind the convergence. Place blue lateral over the hump on the top of the blue G1 or G2 element.

Some convergence adjusters (there were many styles) you can add white lithium grease to in order to loosen.... don't want it too loose or adjustments will vibrate out of place when moving the set.

I have a Zenith service manual with a diagram but it will be a while before I can get to it.

There is a ring at the end of the electron gun the thickness of the convergence yoke that is closer to the glass then the rest of the gun....put the convergence yoke there. Place purity behind the convergence. Place blue lateral over the hump on the top of the blue G1 or G2 element.

Some convergence adjusters (there were many styles) you can add white lithium grease to in order to loosen.... don't want it too loose or adjustments will vibrate out of place when moving the set.

I have a Zenith service manual with a diagram but it will be a while before I can get to it.

thanks :)

more or less, as seen here, then.
https://www.antiqueradio.org/art/RCACTC-11MissingParts.jpg

new coil came today, went in OK.

was able to adjust it down a bit
https://imgur.com/ou5q70O
https://imgur.com/2NZzNn4
still see some retrace lines once in a while, prob not much i can do about it with the video feed in, unless there is a way to mod the blanking amp. :(
oh well .

i'm only seeing a 10v PtP wave on the plate on V21, no idea if this is normal or not :sigh:
R203/204 are new, ( just replaced ) , C135 ( big orange drop) is not new, just ordered it , gonna try a new one to see what happens, this may not help at all, who knows.

You shoud have the same peak-to-peak waveform on both sides of C135, just different DC. If that's what you have, C135 is OK. This is the same AC waveform on all the color difference amplifier cathodes. Look at the waveform shown on the R-Y ampifier cathode. It is 15 v pp including both the blanking pulse and the signal, so I'd guess 10v pp for the pulse alone is OK.

So, I'm still kind of wondering, should I even try to keep working on the IF section given the following...

When I got the set, there had been extensive work on the color PCB for a no color problem.
98% of all non power resistors were replaced, 5% of the caps replaced, and the bandpass coils.
Not to mention,it seemed the entire color PCB had been removed.

Upon going over the work done, I found several quality issues, including 4 resistors of wrong value, 1 cap with a lead open ( hanging), poor solder work and an issue with the color osc coil.

The most disturbing thing noticed is, the shield cover on the IF section was missing, but the bottom was on.
I could not see that any work was done in the IF, but chances are high that coils may have been messed with. (no way to know)

In the years of storage , the IF stopped working completely.
While testing , it was discovered that I could get color through via video injection at 1st video amp.

When checking resistors in IF section, found 2 that were open and about 2 out of tolerance, and the rest were just within tolerance.
After replacing the bad ones, I was able to use the tuner to lock in and get a good clear picture and sound, but w/o color.

And as mentioned earlier in the forum, I then focused on getting color working via video injection.

So, I am wondering this, 85% of the resistors in the IF section are still original that checked “ just within tolerance” but given the fact that chances are good that the coils may have been messed with, is it even worth the effort to replace the rest, given the state now that when I do try to use it I get a good stable b/w video and sound, would there be anything to gain in trying?
Or could it make it worse?
I have no idea.

It's possible that there is IF misalignment which can cause a no color condition if somehow the high video frequencies (where the color information lies) are being attenuated. The only sure way to know is to attempt the alignment procedure with proper equipment, in this case a sweep generator, preferably with frequency markers. This kind of equipment should be available cheaply all over ebay these days since they're no longer useful for servicing modern sets.

You are going to need to do some troubleshooting in addition to shotgun parts replacement if you want to find and fix the problems you are having. The CTC16 is capable of pretty good performance when set up right, I had one about 30 years ago that played really well, so you'll get yours working in time. The fact that you get color with an injected video signal tells me your problem is with the tuner or IF stages, so focus your troubleshooting over there.

You should not worry about resistors that are in tolerance, even "just within." Carbon composition resistors commonly were run off the assembly line, measured, and those within 5% were marked 5%, then the remaining ones within 10% were marked 10% (but they were really all off by at least plus 6% or minus 6%) and so on. So, it is very common in old consumer gear to find resistors that are just within tolerance. The sets were built that way.

There is no way to know if the IF alignment is screwed up without actually measuring it.

The problem with me attempting any kind of IF alignment is...
I have never done it before and have no experience in doing so, and have read that it is not easy to do.
Anything you get from ebay will be in an unknown state functionality wise, and not be in calibration and missing vital input / output probes that can affect the tests you are trying to do, some of which you may try to recreate, but this too can have an affect on the end result.

Right now it seems to be working mostly OK with the injected video, the only issue is the retrace lines that pop up from time to time, which might unavoidable at this point, not sure, given that the normal path of input ( with AGC and everything ) is bypassed.

As I mentioned before, It's unlikely I can ever do an IF alignment myself on it :(

Great to see how good the picture is looking so far! What a crazy journey to get this working and amazing with how messed up this was from the previous owner. Cant wait to see what it looks like once the cataract surgery is done :D

As I mentioned before, It's unlikely I can ever do an IF alignment myself on it :(

Maybe consider transplanting the whole IF board from an unmolested donor chassis(?).

Maybe consider transplanting the whole IF board from an unmolested donor chassis(?).


Unlikely scenario, due to the following.

The chances of ever coming across another CTC16-XL chassis with a viable IF board to use as host astronomically small, and where as the CTC16 is very close to the XL, it's not the same, so it's not viable, furthermore, from what I understand, the IF section is RF tuned to the given characteristics of the tuner installed in the set, so in the very off chance one was ever found, if you tried to use it, it would no longer be matched to the tuner.

My only hope is, if I ever want to get IF working again, is there is a shop within 40 miles that does antique / vintage TV work, and they inform me that they do have a working sweep marker generator, and once I am done with all my repairs, if I really wanted to, they can do the IF alignment.

If you're somewhere around Dallas/Fort Worth I'd be willing to do the alignment free of charge. I don't believe these sets were aligned somehow "matching" the tuner; in fact many set makers bought their tuners from outside sources rather than making the tuners themselves. Otherwise the alignment curves would show something other than marker frequencies in the IF range. Rather the IF was set up to manufacturer specs and the tuner done so separately and then the two should get along well afterwards. Tuners generally don't need much in the way of alignment unless something bad happened. All they really have to do is reject signals outside of the selected channel; all the other frequency traps and response shaping adjustments are in the IF strip.

If you're somewhere around Dallas/Fort Worth I'd be willing to do the alignment free of charge. I don't believe these sets were aligned somehow "matching" the tuner; in fact many set makers bought their tuners from outside sources rather than making the tuners themselves. Otherwise the alignment curves would show something other than marker frequencies in the IF range. Rather the IF was set up to manufacturer specs and the tuner done so separately and then the two should get along well afterwards. Tuners generally don't need much in the way of alignment unless something bad happened. All they really have to do is reject signals outside of the selected channel; all the other frequency traps and response shaping adjustments are in the IF strip.

Almost, but not quite :tears:
I'm in the Austin area, 20 miles north, Round Rock. the place I was referring to is Dean TV Repair on N, N Lamar Blvd here.

the IF was set up to manufacturer specs and the tuner done so separately and then the two should get along well afterwards. Tuners generally don't need much in the way of alignment unless something bad happened.

There is usually an item in the tuner called the 'mixer plate coil', and if it's adjustable, it is part of the IF alignment. If I remember correctly, the RCAs took the mini hex tool for that adjustment.

I had to look at the alignment instructions for this chassis and yes you are correct. That coil, although part of the tuner, is actually on the IF side so yes, it would be part of the procedure since it's really part of the IF strip. I'm guessing its response is a bit more broadband than the other adjustments.

I had to look at the alignment instructions for this chassis and yes you are correct. That coil, although part of the tuner, is actually on the IF side so yes, it would be part of the procedure since it's really part of the IF strip. I'm guessing its response is a bit more broadband than the other adjustments.

Since the instructions are just to tune for max at 44 Mhz (mid band), it does seem likely it's broadband. It's a simple adjustment in any case, even if it does affect the tilt somewhat.

https://imgur.com/Ae7nlTV

getting ready for cataract fix day


I am seeing a tiny bit of image ghosting, most likely due to the video injection, and not much I can do about it. (guess) I have no real i idea what is doing it.

but did notice...

snip / paste
old_tv_nut
"Duh.. I think I'm awake today... If you use a coupling cap and remove L9, you will need to add a grid bias resistor (say, 100k) from G1 to ground. "

Bit on the SAMs. it says,
V3 pin7 (grid) 130 ohm polarity dependent, could 100k be too high?
I think I'll try 500k or lower and see if it makes any difference.

130 ohms is what you read with the circuit intact. The tube does not need such a low resistance to ground, it just happens to be what is there when the normal circuit is connected.

If you are coupling through a capacitor, you need some resistance to ground to bias the tube, but the smaller you make this resistance, the larger the coupling capacitor you will need to keep video low-frequency response. with 100k load, you need a capacitor of about 0.1 microfarad. If you use 50k ohms (47k standard value), you need a capacitor twice as big, and so on.

so i guess the slight image ghosting is unavoidable at this point? I cant think of anything else to do about it really.

"Slight ghosting image" isn't a specific enough comment to guess about. Can't tell how much is "slight," is it really a ghost or more of a smear or ringing, etc. - would have to see it. In any case, your video amplifier and the coupling capacitor would not cause it. I think you should wait to do more nitpicking after the cataract is removed.

"Slight ghosting image" isn't a specific enough comment to guess about. Can't tell how much is "slight," is it really a ghost or more of a smear or ringing, etc. - would have to see it. In any case, your video amplifier and the coupling capacitor would not cause it. I think you should wait to do more nitpicking after the cataract is removed.


For the cataract, i have been waiting for the right kind of weekend, one where both I and my friend are free, ( i need help with it ) and it's not raining and it's hot and sunny, so far this year we have be cooler than normal, but it looks like we may hit 100f next weekend, so we may try then.

as far as what I'm seeing.
https://imgur.com/ifbHDAy
you can really see it there
and slightly here
https://imgur.com/c9mwBtj
not sure what that is.

I don't see anything I would call a ghost. A little misconvergence, maybe some spot blooming on the bright lines, and what appears to be some cross-color (the ragged-looking color mostly to the left of the vertical lines) that should go away when you turn the color all the way down.

Don't obsess over little things until the major things are fixed. It's easy to get hypercritical and expect an analog set to look like a computer monitor. It won't. It is normally watched from ten feet away, so the technician's view with nose pressed against the glass will just drive you crazy trying to reach perfection.

I don't see anything I would call a ghost. A little misconvergence, maybe some spot blooming on the bright lines, and what appears to be some cross-color (the ragged-looking color mostly to the left of the vertical lines) that should go away when you turn the color all the way down.

Don't obsess over little things until the major things are fixed. It's easy to get hypercritical and expect an analog set to look like a computer monitor. It won't. It is normally watched from ten feet away, so the technician's view with nose pressed against the glass will just drive you crazy trying to reach perfection.

https://imgur.com/fWo0QBs

this is what i mean
this shadow should not be there
i can find a good image someplace, but will take time
edit...
digital capture of source
https://imgur.com/CRUNIvo
this is what I mean

Oh, now I gotcha. I would call that a strong negative ghost. I was looking for minor stuff and ignored that as part of the graphics image. Oops! My bad.

The only thing that comes to mind is a bad termination on the luminance delay line.
Check that L14 is not open. If L14 is ok, check resistors in that area.

Oh, now I gotcha. I would call that a strong negative ghost. I was looking for minor stuff and ignored that as part of the graphics image. Oops! My bad.

The only thing that comes to mind is a bad termination on the luminance delay line.
Check that L14 is not open. If L14 is ok, check resistors in that area.

L14 is ok,
its much less pronounced when i use another source as input. but still there.
it goes all the way back to the cathodes of V6 and C1-c via line 64 ( still original ) checked voltage there and was 35v
i did intend to replace that cap, but did not think it was that important.
Its odd that it seems to be more pronounced with some input sources than others, that is what made me suspect an impedance problem.
just to be sure, i could replace that cap, and the resistors in the area with 1% to see what happens.

That's a long time! Thus, one suspects reflections in the cable from the source.

Find a source you can connect to the set with a very short, less than one foot, cable.

If your signal is bigger than needed, as a test try a 6 to 10 dB attenuator with correct resistive
matching at the receiver and see if the ghost gets much weaker.

Don't worry about 1% tolerances - this is a much greater effect.

As dtvmcdonald says, this could be a problem in your source.

But to make sure, I would check that the complete path through R64 and L13 is Ok (2200 ohms), and check C1C by temporarily bridging an approximately 40 microfarad capacitor from line 64 to ground. Then, if the problem is still there, investigate your source.

As dtvmcdonald says, this could be a mistermination of a long cable somewhere, but I think it would have to be a really long cable, like 200meters (656 feet). The luma delay line is roughly one microsecond delay. A back and forth again echo time would be twice that. If you assume the visible width of your picture is about 50 microseconds, the ghost is indeed about two microseconds.

Don't worry about 1% tolerances - this is a much greater effect.

As dtvmcdonald says, this could be a problem in your source.

But to make sure, I would check that the complete path through R64 and L13 is Ok (2200 ohms), and check C1C by temporarily bridging an approximately 40 microfarad capacitor from line 64 to ground. Then, if the problem is still there, investigate your source.

As dtvmcdonald says, this could be a mistermination of a long cable somewhere, but I think it would have to be a really long cable, like 200meters (656 feet). The luma delay line is roughly one microsecond delay. A back and forth again echo time would be twice that. If you assume the visible width of your picture is about 50 microseconds, the ghost is indeed about two microseconds.

I have 56uf caps that I have not used yet, 350v would that be Ok replacement for C1C? or is the 40uf critical?

the cable from video amp to TV is made from thick high quality component video cable and is 5 feet long, over 1/4 inch thick copper conductor solid.
https://imgur.com/1NUU8mC
however the cable to the video amp is cheap and lightweight, i will prob replace it with a 2 foot piece of the same high grade type.

Yes, 56 uF 350v would be OK for a quick test, as the voltage there is only 25 volts, and the tolerance on multisection electrolytics is normally very wide, especially on the high side. If it works, just use it, or look for a lower-voltage rated one for final replacement. There might be some concern about a 350v rated cap not forming completely and therefore producing less capacitance, but I really don't know at what point of over-rating you would get any problems. (I never ran into such a problem in designing gear, because we never used grossly over-rated caps due to unnecessary expense.) So, I say just try it.

A 5 foot coaxial cable is not long enough to generate that much delay. RG59 coax, for example, has a propagation speed of about 2/3 of the speed of light, so 5 feet would be only 5 nanoseconds. A reflection would be delayed 10 nanoseconds, which would be invisibly close to the main signal.

FYI, the speed of propagation in a transmission line is determined by the amount of inductance and capacitance per unit length, and the matched impedance is determined by their ratio. The luminance delay line has a coiled conductor to increase the inductance compared to a regular coax, and the conductor is wound over a grounded conducting sheet to increast the capacitance. The result compared to coax is much greater delay in a shorter, smaller device. An increased inductance / capacitance ratio also makes the impedance higher than 75 ohms, to work better with typical tube circuits. In this case the line is apparently designed for 1800 ohms (R64 in parallel with R63.) When a transmission line is matched on both ends, there is a 6 dB loss. This sort of synthetic delay line usually has some added attenuation at high frequencies and is not perfectly matched at high frequencies either. These shortcomings are compensated by the various coils you see on the output end.

FYI, the speed of propagation in a transmission line is determined by the amount of inductance and capacitance per unit length, and the matched impedance is determined by their ratio. The luminance delay line has a coiled conductor to increase the inductance compared to a regular coax, and the conductor is wound over a grounded conducting sheet to increast the capacitance. The result compared to coax is much greater delay in a shorter, smaller device. An increased inductance / capacitance ratio also makes the impedance higher than 75 ohms, to work better with typical tube circuits. In this case the line is apparently designed for 1800 ohms (R64 in parallel with R63.) When a transmission line is matched on both ends, there is a 6 dB loss. This sort of synthetic delay line usually has some added attenuation at high frequencies and is not perfectly matched at high frequencies either. These shortcomings are compensated by the various coils you see on the output end.

The delay lines for these sets seems to be another impossible thing to find, should someone ever need to replace one.
I remember being amazed when i started to see them made out of quartz in newer sets, still cant quite get my head around how that works. :o

The quartz lines are not for the ~1 microsecond difference between luminance and chrominance, but for a one-scan-line delay, either for chroma phase error cancellation (in PAL) or comb filtering (in NTSC). The quartz lines work by ultrasonic sound to propagate the signal, which is much slower than an electromagnetic wave.

update, I DO see some color via the tuner, weak and sloppy ( smeared and bleeding ) , nothing as exact and sharp ( on target ) with the injected video.

best I can get through the tuner / IF

https://imgur.com/dGHxwXP
https://imgur.com/Z9N1j2H
pretty ugly :tears:

no where near a clean color with direct input.

We are going to attempt to fix the cataract this sat, I'm going to leave it in tuner input for now, so when i put the CRT back in i can use the bar dot generator to try and align the convergence, then switch back to direct video.

Cataract repair successful! :banana:

Start
https://imgur.com/MFKZ9DT

safety glass removed.
https://imgur.com/OK4HM7c
https://imgur.com/u37ddqC

problem causing krud
https://imgur.com/XEGMLIN

repair complete
https://imgur.com/YkDt2YL
2 OEM legs were lost over the years in storage, once done, they will be all 4 matching.

I did have a slight complication, a secondary CATaract had to be removed before it could be completed.
https://imgur.com/Cub0Mxk :lmao:

Now I'm ready for purity and convergence. :)

the one thing i really don't get is...
in this video, https://www.youtube.com/watch?v=dQ_i_8rTIR4
shango066 points out a "flaw" on the surface of the CRT at about 8:30, i saw the exact same mark on mine :confused:
is this on all of them? some of them? very odd, unless it is a deliberate mark. :confused:

My guess is the glass was inspected for flaws before phosphor application if one near the edge was found mark it to be bottom or top in the masked off area like that, then apply the phosphor and off to the races of the rest of the build.

I take it you used the heat gun method (which is the least safe)...I'm thinking of trying that today on a couple RCA style cats. Been using the clothespin and sun method on the RCA style and I can't seem to get the finesse right to not crack the glass.

I like the secondary cat a lot better. :thmbsp: All you probably need to get that one off the tube is some food and followed by windex and paper towel for the fuzzy residue they leave.

Cataract repair successful! :banana:

...
I did have a slight complication, a secondary CATaract had to be removed before it could be completed.

Now I'm ready for purity and convergence. :)


Woohoo!

Regarding the new cataract, it may make your convergence off by whisker. :tongue:

Regarding the flaw, it definitely is interesting. How exact is the match to the video? Same kind of line of blotches or the exact same pattern of blotches?

I wonder of the graphics ("30" and the star) were made by taping a transparent negative to the faceplate during exposure, and sometimes resulted in phosphor being pulled off when the negative was removed.

Regarding the flaw, it definitely is interesting. How exact is the match to the video? Same kind of line of blotches or the exact same pattern of blotches?


exactly the same, in the same place. wired

all CRT parts in place,
https://imgur.com/p8dy1Am
static went OK , dynamic not so well, may have to rep;ace some stuff on the convergence PCB .

all CRT parts in place,
https://imgur.com/p8dy1Am
static went OK , dynamic not so well,...
You might have the convergence yoke positioned too far front-ward. Also, the deflection yoke normally sits approx. 1/4 to 3/8 inch shy of being fully seated against the CRT bell. During purity set-up, you find this 'sweet spot' for best red purity. And yes, this is from factory-sponsered 'RCA school' where field reps actually visited dealers.

On rectangular CRTs, the 'sweet spot' occurs about 3/16 to 1/4 inch shy of the yoke being fully seated.

Looks like the internal dag hides the convergence pole pieces. Try moving the convergence yoke back and forth a little, looking for the spot with the greatest effect on the convergence.

Correct, in the newer rectangle ones, you can see where thy go.
I moved it hack some and it helped a bit, cant get it perfect, prob never will.
https://imgur.com/VoHMjmU

as mentioned, I will most likely never get rid of the retrace lines until l find some way to get IF aligned. :(

it's been so long that I forgot how fun convergence was, you do the static, then start dynamic, then halfway through, you see that Static is off again so you do that over, and keep going round and round, till it's as good as you can get it. :o

I'd say that looks good.

Hint on the iterations, if you have to do another one sometime:
Instead of going back to the static adjustments right away when they are knocked off a bit by the dynamics, just keep adjusting the dynamics for parallel lines that are off the same amount all over. Then a single static adjustment will come close to getting the whole screen in, and very minor dynamics will finish the job.

I’d say you summed up the process well. Good results.

Ironically, while we were waiting for the CRT to heat up in the sun, we watched the moon landing on "Apollo in Real Time" while working on a CRT for a TV that they surely watched it on when it happened.

I decided to experiment some today.
Wanted to see what I would get if I injected video at the point of the video detector x7, rather than 1st amp.
When I tried, I got the same awful smeared color I saw last time I tried getting color via tuner / IF.
So I decided to try to adjust L7 (4.5mc trap) while in this arrangement, and it made a vast improvement.

So, I hooked everything back up for tuner/ IF mode and tried again.
This is the result
https://imgur.com/IyB3n3Z
https://imgur.com/fDLeg41

much better than it was,
but not perfect :/
the shadow is still there slightly, not sure why, bleeding on strong red, slight diag banding noise .
but it's miles ahead of where it was when i started!

and there is no doubt now that the shmuck who had it before me messed with the coils, IF, and color. :yikes:

If you have a video playing through the tuner (not still mode, so the audio is not muted) you should see the 4.5 MHz interference dancing around with the audio, and may be able to tune the trap precisely for minimum interference. If the trap is tuned a bit too low, resetting it may reduce your color ringing (but of course, if the previous idiot fiddled with everything, other mistunings may be contributing the color ringing).

If you have a video playing through the tuner (not still mode, so the audio is not muted) you should see the 4.5 MHz interference dancing around with the audio, and may be able to tune the trap precisely for minimum interference. If the trap is tuned a bit too low, resetting it may reduce your color ringing (but of course, if the previous idiot fiddled with everything, other mistunings may be contributing the color ringing).

Right now, i am only feeding it video to the tuner, when i adjusted the 4.5 MHz,
and i had to tune it pretty far to get it to this point, I intend to try later with sound hooked up, but I'm not sure how much better it will get.

sound hooked up, and as I thought, I can't get it much better than shown in the last pics.

so now I have a choice :p
use the video amp and video injection and get retrace lines 40% of the time, or use tuner and get slight color ringing and no retrace lines.:D

until i can get it aligned anyway, I an not going to touch the other coils...

and on a unrelated note..
one thing I noticed about THIS TV anyway, i don't know CT16/XLs do this but, when I turn it off, as it powers off, there is this cute little "fwip " sound out of the speaker. it has always done this since I got it, I don't mind it, I have always wondered do they ALL do it or just mine?

Does it do the little 'fwip' at all settings of the vol control? This would at least tell you whether it's originating upstream or downstream of the vol control.

Does it do the little 'fwip' at all settings of the vol control? This would at least tell you whether it's originating upstream or downstream of the vol control.


The “chirp” , for lack of a better word, only happens when volume is turned up, it even does it with the audio detector tube V8 removed.
As I mentioned, I really don't see it as a problem per-sey, as I always found it endearing to the set.
I just wonder has anyone else noticed this? As I was way to young to remember if the CTC-10 that my parents had did it or not.

I've had this noise on RCA's before, always turned out to be the electrolytic connected to the 6AQ5 screen grid supply

here is another annoyance problem i have noticed, hard to describe, when ever there is something really bright on the screen , it causes a brightness / contrast problem to everything to the right of it, but not the left,

not sure what would cause this
tried to get a pic of it.
https://imgur.com/ao5befU
https://imgur.com/HFbdHMe

UPDATE
this is corruption on the source
caused by the MKV video to DVD software program i used :(

??? In the first pic, the big bright thing is on the right, and the large darkened area is on the left of it. The second pic is the other way.

If the soft edged darkening is what you are talking about, and you are going in with your video amp at the detector, it could be because you are using a too-small coupling capacitor for this point.

When you have questions like this, you need to give full details of your setup before diagnosis is possible.

??? In the first pic, the big bright thing is on the right, and the large darkened area is on the left of it. The second pic is the other way.

If the soft edged darkening is what you are talking about, and you are going in with your video amp at the detector, it could be because you are using a too-small coupling capacitor for this point.

When you have questions like this, you need to give full details of your setup before diagnosis is possible.

right now, I am using the tuner / IF for input . the video source is a DVD i made using a blu-ray .mkv source converted to DVD, i did see the same thing on a color monitor ( composite ) when i checked , so i suspect the source.

I tried a VGA to composite, and it was no where near as bad, bit still slightly there.
I guess the TV just does not like this scene that much

I was wondering, would there be anything to gain to re-do color AFC setup now that color is getting through the IF somewhat? (vs being done with injected video ) or could that just risk messing things up?

...

I was wondering, would there be anything to gain to re-do color AFC setup now that color is getting through the IF somewhat? (vs being done with injected video ) or could that just risk messing things up?

If it ain't broke, don't fix it. :D

ran for 1 hour w/o problems.
other than slight color ringing caused by IF alignment,
HV chamber was cool to touch, after.

still seeing some darkening when there is a bright object on screen, just slight though.
may replace C30 & C25 with new to see if that helps.

still have to put in WORKMAN themistor set for degaussing circuit, the one in set is weak.

it seems that replacing C30 & C25 did help a bit! :)
https://imgur.com/BQCGCmX
https://imgur.com/yTOMLmV

So, it looks like aside from getting the IF aligned at some future date, it looks like I have done all I can for the set now. :)
Perhaps work on the cabinet a bit, but I'm not very good at that. :/
I have run it for over 3+ hours now w/o problems with chassis out, about time to stick it all in and do fine convergence on it.
Which brings up a slight annoyance problem, over the years and years in storage, the knobs for volume / on-off and brightness were lost, :( all others are still there, not sure what to replace them with.
They don't have to be EXACT, they just have to work.. :/

So, right now my choices are with the IF problem...

Ignore it for now. ( bleeding on reds is annoying, but not THAT bad )

Try to tweak the coils w/o any equipment or knowledge and hope to eyeball it to get best picture ( prob no the best idea, but an option )

Try to get a Heathkit IG-57 from ebay some time, which will have no probes, ( can be made ) and no attenuator ( can be got separately ) , which will be in an unknown working state, but can be calibrated / tested via the manual, in order to do an alignment procedure that is tricky and not fully understood :/
Example, SAMS says to disable oscillator section of the mixer-osc, but gives no info on how to do it.
Taking a wild guess, I would say removing one of the bias voltages to the tuner, but I'm not sure.

Or lastly, hope to set aside enough $ some day to haul it 20 miles to a place that can hopefully do it, & get it there & back w/o damage :/

sigh...

So, right now my choices are with the IF problem...

Ignore it for now. ( bleeding on reds is annoying, but not THAT bad )

Try to tweak the coils w/o any equipment or knowledge and hope to eyeball it to get best picture ( prob no the best idea, but an option )

Try to get a Heathkit IG-57 from ebay some time, which will have no probes, ( can be made ) and no attenuator ( can be got separately ) , which will be in an unknown working state, but can be calibrated / tested via the manual, in order to do an alignment procedure that is tricky and not fully understood :/
Example, SAMS says to disable oscillator section of the mixer-osc, but gives no info on how to do it.
Taking a wild guess, I would say removing one of the bias voltages to the tuner, but I'm not sure.

Or lastly, hope to set aside enough $ some day to haul it 20 miles to a place that can hopefully do it, & get it there & back w/o damage :/

sigh...

Ways to disable osc stick the tuner between channels (all turret tuners and some water types will open the osc coil circuit between channels, take a spare osc tube you don't like and clip a grid or plate pin off and stick that tube in.

...
Try to tweak the coils w/o any equipment or knowledge and hope to eyeball it to get best picture ( prob no the best idea, but an option )

...

Oh, no, no, no :no: :thumbsdn:

Oh, no, no, no :no: :thumbsdn:

+1, it's not going to work. There are no visual clues to know when the IFs are aligned, unlike in a radio where normally they are set for peak response.

+1, it's not going to work. There are no visual clues to know when the IFs are aligned, unlike in a radio where normally they are set for peak response.

I was not REALLY that serious about trying option 1, knowing that it would most likely do more harm than good. :D :sigh:

I will most likely run it as is for now, for the distortion can be minimized by messing with fine tuning, IE,the ringing in the red DOES move when it's adjusted as does color intensity ( noise ), but the ringing never fully goes away, no matter what I try, when I input via tuner, but on the positive side, horz hold has no effect on color at all.

At this point, I still have re created the missing top cover to the IF section, tube shields are in place.
I can't really imagine the cover being off having THAT much of a drastic effect on things, I just have to find a way to have one made from the template I was given.

I just have to wonder, if I do get my hands on a sweep marker generator at some point, given the complexity of the procedure, could a noob at such a task like me do it. :o

I just have to wonder, if I do get my hands on a sweep marker generator at some point, given the complexity of the procedure, could a noob at such a task like me do it. :o

As long as you have alignment equipment in proper working condition and the service data for the set I think you will do just fine. I was inexperienced once myself, and at 46 years old I did not have the benefit of having worked on these sets "back in the day" either.

I think I will have to do the alignment on my Mitsubishi Trinescope set since it displays the classic signs of misalignment; tunable ghosts and excessive hue shift with fine tuning. I will have to do this without an alignment procedure, I only have the various carrier frequencies known from the instruction manual (and they're not even the usual 45.75MHz either, I think it was 24 or 25MHz).

I'd make the shield before worrying about the alignment... You would be surprised some of the wacky problems removing a shield from a working set can cause.

It ain't terribly hard to make that shield out of sheet metal with hand tools. Photo copy the template, cut out the template and trace around it on to a small piece of sheet metal (most home stores have 1sqft pieces of sheet metal) and tape the template down to the metal clamp the metal down to a piece of wood you don't mind drilling into and drill through the hole marks in the template. On the square can holes drill the biggest round hole through the center as fits in the border and file out the corners to get square or if you have a rotary dremmel use the cutting wheel to cut the can holes instead of the drill. Once the holes are done cut the outer edge you marked earlier out with tin snips. File and or sand and Sharp edges off pound any warps or dents flat with a hammer and install.

If possible use a soft metal like aluminum or copper... I've made stuff like that out of sheet steel and it can be a bit of a pain to work with. Also wear thick canvas work gloves so you don't cut your hand like I did yesterday.

As long as you have alignment equipment in proper working condition and the service data for the set I think you will do just fine. I was inexperienced once myself, and at 46 years old I did not have the benefit of having worked on these sets "back in the day" either.

I think I will have to do the alignment on my Mitsubishi Trinescope set since it displays the classic signs of misalignment; tunable ghosts and excessive hue shift with fine tuning. I will have to do this without an alignment procedure, I only have the various carrier frequencies known from the instruction manual (and they're not even the usual 45.75MHz either, I think it was 24 or 25MHz).

That's why I'm looking at the Heathkit over the B&K Precision , even though the B&K seems to be a better unit, it's useless w/o probes, which are impossible to find.
Heathkit, however even if you do not have any probes, has how to make them, and test / calibrate the unit in the manual.


"I'd make the shield before worrying about the alignment... You would be surprised some of the wacky problems removing a shield from a working set can cause."

I'll prob do that soon. Most likely seek aid from a friend who has more exp in the area, as my hands areattuned to more delicate work like soldering ( fine pitch ) and so on, and it also does not help that I have only partial use of the right hand :( ( De Quervain's) too many years of holding tools in the same position, like , soldering irons.
I can use the hand ( grasping and such ) for short bits of light work, and thus I was able to the TV work slowly over the months, but something like the shield would cause a flair up. :(

Replacement IF shield came and went on ALMOST, w/o a problem. :D
https://imgur.com/hjMsDmV
https://imgur.com/RrRS7IP

it's that slight difference between the CTC-16 & CTC-16XL again.
XL has a different video output, so the hole for it is slightly offset, so it had to be made to fit .

but it IS on there now!

As you can see, it's mostly all covered now, except for a small area next to V4, over R22 (sound reject), which i don't think will matter much, or perhaps I could shape a small piece of HVAC Foil Tape over that bit and put kapton over it.

https://imgur.com/HGb3e1Y
chassis installed, set in final location , ready for final convergence.

back installed. (for now,)

Will prob have to work on the convergence PCB at some point, could not get it as neat as I wanted, not that they are ever perfect, but , there was some unevenness with red /green horz at the top where bot was perfect and could not get it to even out.

will leave it for now.

https://imgur.com/3hZnlmW
https://imgur.com/2IRpnlp

the sucker puts out a lot of heat! :)
but not where is should not!

https://imgur.com/ia7K5mV
https://imgur.com/OXaBvHJ
a pic of the stubby legs i got to fit under my screen & the cooling fans.

Convergence problem in detail.

As mentioned in previously, set has been moved to it's final location and spent over an hour trying to make fine adjustments.
Noticed there was a slight convergence problem, this is only seen at the top with red/green, bottom, left & right were able to line up w/o issue.
R-G vert lines (top) are least affected, and almost lined up completely, but the pot for it (r27) had to be turned to the extreme point of travel to get as close as I could get it.
R-G horz lines (top) are worst affected, as they appear to be distorted, IE, red below green on one part and red above green on others, no amount of adjustment would clear it up, at one part at the top, R-G would be off, so I got it as close as I could for now, and will try and fix when I do the IF alignment.

I seem to remember seeing somewhere that the diode pack on the convergence PCB (x6) is a possible trouble spot, and / or the the orange drops.
Has anyone seen something like this, R-G issues only at the top?

The diode pack is multi section and has its fingers in every part of the dynamic convergence pie...also most of those were selenium diodes which are not the most stable rectifier technology...

What I do when I repair a convergence board is change the caps and diode pack, and check resistors...if that don't fix it there can be 2 problems (the set I most recently did this on had both) 1 the convergence yoke happens to work better somewhere under .5" fore or aft of its intended resting place, or the dope before you installed the clover backwards so the green magnet is over the red gun and the red is over the green..... normally I wouldn't suspect the latter but the set that had that problem had new convergence diodes hacked in and resistors clipped out with " Ray Charles soldered this in with his feet" type craftsmanship...

The diode pack is multi section and has its fingers in every part of the dynamic convergence pie...also most of those were selenium diodes which are not the most stable rectifier technology...

What I do when I repair a convergence board is change the caps and diode pack, and check resistors...if that don't fix it there can be 2 problems (the set I most recently did this on had both) 1 the convergence yoke happens to work better somewhere under .5" fore or aft of its intended resting place, or the dope before you installed the clover backwards so the green magnet is over the red gun and the red is over the green..... normally I wouldn't suspect the latter but the set that had that problem had new convergence diodes hacked in and resistors clipped out with " Ray Charles soldered this in with his feet" type craftsmanship...

I have had the Convergence yoke on and off a few time now, so I know that red is over red and green over green, I do not know however, if the Convergence Coils themselves were perhaps ever removed or put back in backwards or not, never thought of that possibility.

But as suggested, will replace diodes, caps go over the resistors, and see if gets better at a future date & go on from there.

it seems the diode array can still be found for it. :)

ref.
http://www.nteinc.com/specs/100to199/pdf/nte120.pdf

here is something not seen very often, anime from 2019 shown via windows 7 on an RCA CTC-16XL! :)
https://imgur.com/jvD36lr

here is something not seen very often, anime from 2019 shown via windows 7 on an RCA CTC-16XL! :)
https://imgur.com/jvD36lr

Nice. I do some similar stuff. Currently using a Windows 10 rig but my 7 rig is still on hand (forced to go to 10 because the new rig I built lacked driver support for USB on 7 so I couldn't use a keyboard/mouse to make the installer complete). I've ran downloaded copies of the original 1967 season of Lupin III, and cutie honey (1973), up through the series premiering on Animeshow.tv on everything from my RCA 21CT55 to my sony super fine pitch Wega.

I'm going to guess your watching fruits basket in that picture.

Nice. I do some similar stuff. Currently using a Windows 10 rig but my 7 rig is still on hand (forced to go to 10 because the new rig I built lacked driver support for USB on 7 so I couldn't use a keyboard/mouse to make the installer complete). I've ran downloaded copies of the original 1967 season of Lupin III, and cutie honey (1973), up through the series premiering on Animeshow.tv on everything from my RCA 21CT55 to my sony super fine pitch Wega.

I'm going to guess your watching fruits basket in that picture.

Correct! :)

I am very very into Furuba, ( & all shoujo in general )
When I don't have my face burred in work and electronics, I'm spending time on Anime and fansubbing.
Our group is , http://www.live-evil.org/

In regard to protecting the FBT, given that there is near zero chance of finding one for a CTC-16X series, going from the starting point that it seemed in excellent condition to start with, ( no wax loss seen, or arcing traces ), it seems I was lucky getting this.
From all the many threads I have read, the most important seems to be HOT (6JE6A) cathode current, & keeping it as low as one can w/o losing function ( below 200ma).
To aid in this, converting the focus to solid state helps, as it removes the draw from it's heater winding.

What also is said to help is more ventilation for the HV cage, to allow any generated heat from the FBT/ HV RECT to escape more easily , this is done by adding holes in key places and forced air via fans, perhaps on the back.

At this point, I can't think of anything more to do to try and protect the FBT, as shown in the thermal scan before, w/o the back on that has the fans on it, the HV on mine is very cold after an hour running.

https://imgur.com/3hZnlmW

What can't be seen there, and this kind of surprised me, is I drilled 4 large holes in the front of the HV cage, and there is no heat at all seen coming from them, I did not expect things in there to be so cool as not to be able to see the holes on infa red. :o

How does one know if a FBT has ever been replaced in any given RCA? There really is no way to know, is there, w/o knowing the history of the set. You can make a guess by looking, but never know for sure.
I have 2 examples here, Rocket's CTC-16XL and Freakaftr8's CTC-16.
I will look at mine closer this weekend.
I suspect that Freakaftr8's is original and Rocket's a replacement.
Reasons...
Freakaftr8's , Darkened metal at base, same as chassis, doughnut color darkened, wires held with black tape ( common with oem )

Rocket's , metal at base much lighter than chassis, doughnut color cleaner looking, no black tape seen.

https://imgur.com/d4cpPzR
https://imgur.com/W4JoHPn

I would say Rockets is for sure a replacement. That tape is usually a giveaway. Also the red silicone as well.

https://imgur.com/LHDJKjQ
https://imgur.com/euosC1y
https://imgur.com/OMDJAt8
https://imgur.com/3a27NoW

Mine is def an original OEM.

however there is very little wax loss for a flyback that is this old, so I guess that is a good sign.

you can see the holes I drilled in the cover in one of the pics.

Freakaftr8 you cursed my CTC-16XL! :cry:

tonight for some odd reason, the IF decided to fail again after working mostly for many months , now i get no video or sound T_T

i decided I was not going to bother hauling back up to the 2nd floor again and take it all apart to find out why at this point, but just switch back to video injection mode, and hope to fix it when ever I attempt to do an IF alignment on it. It gets better color this way anyway , the trade-off is retrace lines sometimes.
https://imgur.com/8wFk2gc <-- ignore the cheap cellphone cam shutter noise
pretty damn good for having bypassed the tuner / IF :banana:

Oh boy. This is the fun part of running vintage gear. its always something. reminds me of a certain Fold Thunderbird SC that I used to own.

my TV via video injection
https://youtu.be/7V3etX2NsS4

Looking good! Did you figure out what happened to the IF stage? Mines dead too thanks to a bad 6KA8.

My guess is that I lost another resistor in it someplace,

I had just a raster at first when I took it out of storage before I replaced R48 & R50.
then it was a huge fight just to get it to pass any color, It was still out of alignment bit mostly working.
but 90% of the original resistors are still in the IF section. I guess I should have changed them when i had the chance.
most of them were just in tol, and I posed the question should I just go and replace them now ( the old carbon core with new metal film ) and It was said, " if it aint broken "
Well now it is. T_T
but I don't want to go through the trouble of hauling it back upstairs and taking it all apart right now ( that damned metal cover on the bottom )
I'll prob wait till I get my hands on a good sweep function generator and try to do it all at once.

my TV via video injection
https://youtu.be/7V3etX2NsS4

Aside from the brightness looking a bit high and the retrace lines it looks perfectly fine.

When you have a few of these beasts in regular service you learn to bring the tools/workbench to the set and not the other way around... I have a particleboard shelf from a component stereo cabinet I use as a base to solder on so I don't burn the carpet. Having a dud brightener and some octal sockets and bases to make 3' extender cables so you can set the chassis ontop of the cabinet and use the set as its own workbench/test jig makes life easier too...Though the Zenith service saver bottom hatch makes life even easier...Just set the set on its side pull the bottom cover and back and every component is accessible and the set can be powered up for tests any time you want.

It's not as bright as it may seem in the video due to the lousy camera I used, ( trying to adjust to a dark room, and the TV being the only light source )
brightness is at about 70%, grayscale setup was done with CRT bias set to lowest & it can still produce a very bright picture, ( good sign, I guess. )

The retrace, I have never been able to fully figure out. :(
It was less noticeable when going via tuner, but never fully gone, and I was never able to find out why, but suspect due to weak horz blanking.
SAMS has the blanking pulse for the CTC-16(XL) @ 15v ptp, and the CTC-15 @ 25v ptp (all 6gu7)
and the CTC-20 @ 17v ptp.

The VERY BEST I ever got out of mine, ( far side of the .22 cap going to the cathodes of the y-amps ) is 9-10 , never near 15v, and I have been all over the circuit, trying to work out why it's not higher.
I don't think changing the value of the grid resistor (390k) will do any help, but what I am thinking of is changing the plate resistor (47k 2w) with a precision 3w 100k pot, to see if adjusting it may get a bit more signal out of it, but that is just an idea at this point.

When the circuit ain't good enough with the factory configuration and fresh parts there is either a weird problem (like current leakage in weird place like a tube socket) or it is time for decade box/potentiometer engineering...

I did replace the grid resistor, (390k) plate resistor (47k) & coupling cap (.22) , I did see that it is very closely tied to the CRT bias switch, but I did not change any of those resistors there, cause I did not think it would have that much of effect, I do see that the cathode of the blanking amp is tied to the cathode of the bandpass, 820pf / 390 ohm paralell to gnd, these were replaced by the person who had it before me , the resistor checked OK (5% carbon film) the cap was correct, (checked by # on top)
I guess I should have replaced them too . :/

so i guess something like... https://imgur.com/cfcsbCt could help me track down the IF failure W/O having to remove the chassis.
I'm also thinking of getting a nibbler tool to make bigger air holes in the HV case, as im always paranoid about the FBT. :(

:uzi:
Who would have thought it would be so hard to find plug-in test adapter sockets for tubes these days.
:(
I want to probe the voltages on the IF tubes w/o too much of a hassle, but having trouble getting the ones needed, I think I found a 7 pin, and if I have to, i'll tack wires on to a cheap 9 pin socket saver if i have to, ( no way I'm paying $50 ish for a 9 pin test socket ob ebay )

9 pin test socket made, https://imgur.com/CGv43mR

waiting for 7 pin to arrive

I now have insight on what happened to my IF section...
https://i.imgur.com/hlFwF2h.png

something is VERY wrong with the 2nd if, and thus it takes 1st down with it.
it is NOT bad tubes, cause i checked that.

I wont know for sure till i have the time to pull it all apart and check caps/ resistors / tube sockets.

Are the voltages off the 6JH6 1st IF correct? It's hard to read but c17 is tied to all those that goes to ground. is it shorted?

Are the voltages off the 6JH6 1st IF correct? It's hard to read but c17 is tied to all those that goes to ground. is it shorted?

if 2nd if is down then 1st can't work
the 2nd gives the plate bias to the 1st

not sure what it is yet, Remember i have a CTC-16-XL.
almost the same as the 16, but different in quite a few ways.

Right now I am very suspicious of c12 ( c21 on the CTC-16 version ) , if that was leaky that may cause what I am seeing.

when i get around to pulling the chassis to try and fix this, i will most likely replace all the.001 caps

on a unrelated note, I took a nibbler tool to my HV cage, to add even more airflow, this is the thermal scan after 15 min, w/o the fans.
https://imgur.com/XSifzsf

Does anyone know why the second IF stage is "floated" above ground by about 150V? Is it an effort for using the second IF stage as a voltage drop to provide plate voltage for the first IF stage? Kind of like the audio output tube circuit in some B&W sets to provide an approx 140 volts source at its cathode. I see where RCA used this arrangement for many different models.

If the AGC were way off, the second IF could be biased such that the voltages for both the first and second IF could be way off. Go back and check the voltages on the first IF stage as well. There is a good chance they are off as well.

Does anyone know why the second IF stage is "floated" above ground by about 150V? Is it an effort for using the second IF stage as a voltage drop to provide plate voltage for the first IF stage? Kind of like the audio output tube circuit in some B&W sets to provide an approx 140 volts source at its cathode. I see where RCA used this arrangement for many different models.

If the AGC were way off, the second IF could be biased such that the voltages for both the first and second IF could be way off. Go back and check the voltages on the first IF stage as well. There is a good chance they are off as well.

I only saw about 20-30v on pin 5&6 of the 1st IF ( should have been 160v) and nothing on 1,2,7 (less than 1v) , and so I look at the 2nd IF , and saw it had the plate voltage, but everything related to the cathode's flothed ground was very low. (30v)
even with 1st IF removed the cathode voltage was gone.

I can see WHAT is happening, but since I was probing with tube test sockets, it don't know why yet.

with 1st IF removed, should i not see 160v ( approx) on the cathode of the 2nd?
I'm just going to have to make time at some date to take it all apart and check all resistors / caps in the area again.

another thing that may explain what i am seeing, this is doing EXACTLY what it did before i replaced R48 & R50, i put in 1/2 watt carbon film ones, it said to use 1/2 watt, perhaps they did not hold up, perhaps it's time to replace every resistor off that power line with 1 watt resistors. ( and the .001 caps )

EDIT-
It's looking more and more like that is what the problem is, seeing a good 300+ v at point 3, and on the far side of R51 getting power to the plate of 2nd IF. But there is crap at point 14 other side of R50, hardly 30v.
Time to change it again with a 1w and the filter caps.

Those .001 wax ceramic ELMENCO caps I have heard are usually either bad or going to go bad soon..

Those .001 wax ceramic ELMENCO caps I have heard are usually either bad or going to go bad soon..

I always thought those tube cap things were funny looking, but i never thought they would cause this much trouble :/

I always thought those tube cap things were funny looking, but i never thought they would cause this much trouble :/

The elmenco caps .001 and up are just wax caps in disguise.

The elmenco caps .001 and up are just wax caps in disguise.

I had never seen caps like them before i saw them in this set, kinda took them for resistors, till they were pointed out as CAPs in the SAMs, guess i should have replaced them, as they are clearly a source of trouble now :jawdrop:

I'm guessing that this will be a good replacement for them.

667-ECQ-E10102KFB (mouser )

I'm in no big hurry to get IF working again, as it's working OK via video input, I will most likely wait till it gets cooler.

Those caps are the usual caps if you want 1 kV, very reliable.

BUT ... why the "B" on the end???? That's NOT usual, as it means a crimp in the
leads. Normally for old sets one leaves the B off. And saves a couple of cents.

I did not even know I had this...
https://imgur.com/7rYdtgs

playing one of the " The Prisoner " laser discs, I let it run past the end of the credits on the 2nd disc and saw this was there :o
never know it was there.

It's still hard to get a decent picture, it looks better than this :/


"BUT ... why the "B" on the end???? That's NOT usual, as it means a crimp in the leads." ( ref to prev post)
true, i don't really need the crimped ones.

I guess while I'm in there later, ( with the bottom shield of the IF off) I will replace the 2 detector diodes, (1N60), not that they are bad now, but I hear that they do wear out, and I would rather do it now than later.

That test pattern looks good! That's with injected IF?

That test pattern looks good! That's with injected IF?

yes, at the 1st video amp, i lifted up one end of L9 and am feeding in directly in.

I did have to build a video amp, cause composite video is about 1.1 v ptp, and the CTC-16/X wants 3.5 there.

I have always wondered about C70, the ugly white elmenco .001 (2kv) paper cap under the chassis hooked to the plate of Vert output, as of now, mine is still the OEM, as it has not given me any problems... YET...
I'm thinking when I have things apart to fix the IF, to go ahead a change it, but with what, as far as I can tell, as long as it's .001 and 2k (or more ) it should be fine.
So I was thinking of using Mouser # 594-S102K33Y5PP63K5R

I'd replace the elmenco with this https://www.mouser.com/ProductDetail/Panasonic/ECW-H20102JV?qs=sGAEpiMZZMv1cc3ydrPrF0%252BjlB8SXIRu8z tgyl3M9nM%3D

The elmenco tubular ceramic shell caps are actually paper dielectric caps so they should be replaced with film caps.

Ceramic dielectric caps should never be used in a TV unless the original part was a ceramic dielectric cap. Original ceramic dielectric caps are easy to identify, they are either flat discs with 2 leads exiting the edge or they are thin ceramic tubes that never have a capacitance higher than 200pF...

It is usually best to assume in any tube TV that any cap 1000pF (=.001uF) and up is paper unless it is flat disc ceramic or a later film type such as a Sprague orange drop.

I'd replace the elmenco with this https://www.mouser.com/ProductDetail/Panasonic/ECW-H20102JV?qs=sGAEpiMZZMv1cc3ydrPrF0%252BjlB8SXIRu8z tgyl3M9nM%3D

The elmenco tubular ceramic shell caps are actually paper dielectric caps so they should be replaced with film caps.

Ceramic dielectric caps should never be used in a TV unless the original part was a ceramic dielectric cap. Original ceramic dielectric caps are easy to identify, they are either flat discs with 2 leads exiting the edge or they are thin ceramic tubes that never have a capacitance higher than 200pF...

It is usually best to assume in any tube TV that any cap 1000pF (=.001uF) and up is paper unless it is flat disc ceramic or a later film type such as a Sprague orange drop.

should prob get this one then,
https://www.mouser.com/ProductDetail/Panasonic/ECW-H20102RHV?qs=sGAEpiMZZMv1cc3ydrPrF0%252BjlB8SXIRuF 3O1VdC5JV4%3D

as the other one is not stocked and takes a long time to get. :(

I was looking at the disc-types for a replacement, cause there there were very few film types in stock that met the need, there were more choices in disc, but If it must be film to replace paper, then the choice is clear.

You can also go cheap and use a wima brand... I've used their 6kv parts for replacement of the 6kv paper caps used in early post-war electrostatic deflection sets with success. Their lower voltage parts are probably just as good.

Sorry for the non-stocked link. Navigating mouser on a smartphone is deep in fish out of water territory for me.

Whole bunch a .001 caps ordered for the IF, + ugly one on the bottom, also have the 4 new caps coming for the convergence PCB, & the diode, also ordered this to swap out the 47k res on the plate of the horz blanking amp, (652-93A1A-B28-A20L ) to try to get a little better output from it.

https://imgur.com/Txm8oBx

back on the workbench to fix the IF fail.

2 hours later...

https://imgur.com/4aAYWzG

IF is alive again!

:banana::D
Still gotta change that ugly cap on the bottom and try to get the retrace to work better, and replace some parts in the convergence PCB,

but that's enough for 1 night! :yes:

Good work.

You may be coming to appreciate one of the charms/curses of owning a tube color TV....If you use it regularly like it would have been new then it will always need some service work within 6-24 months of its last bench time. Whether it is a charm or a curse depends on how much you like working on it...

Good work.

You may be coming to appreciate one of the charms/curses of owning a tube color TV....If you use it regularly like it would have been new then it will always need some service work within 6-24 months of its last bench time. Whether it is a charm or a curse depends on how much you like working on it...

Its a curse. Any rare or valuable TV is very stressful to work on. My blood pressure rises from 120/75 to 148/95 until its fixed. This is by actual measurement. This does not usually happen on radios, though it did happen once when I discovered that the RA17C12 I bought had had all the paper and electrolytic caps already cut out, and the harness cut. This of course ruins my
usual method of avoiding a miswired new cap. [Addendum: well, not ALL of them ... the hard to get at ones were still there.]

it did NOT like this cap as a replacement for c70 :O 667-ECW-H20102RHV


put it in ans lost all vert sweep. put the original elmenco back in, and it worked again , weird...

Its a curse. Any rare or valuable TV is very stressful to work on. My blood pressure rises from 120/75 to 148/95 until its fixed. This is by actual measurement. This does not usually happen on radios, though it did happen once when I discovered that the RA17C12 I bought had had all the paper and electrolytic caps already cut out, and the harness cut. This of course ruins my
usual method of avoiding a miswired new cap. [Addendum: well, not ALL of them ... the hard to get at ones were still there.]

It only stresses me if 1.) it drops me down to 1 or less working sets in a main viewing room, 2.) if I'm in the middle handling something super-delicate like reattaching a hair-thin coil lead, or 3.) I have a couple of sets disassembled/mid resto that I gotta finish and or reassemble fast to reorganize for something (which I'm sorta dealing with now).
If I let it bug me that bad the number of such sets I have now would raise my blood pressure high enough for my head to shoot off.:D


Strange that that panasonic cap didn't work...Did you check resistance across it? maybe you got a shorted factory dud or something.:scratch2:

I'm not sure why it did not work T_T

I just know that after I hauled the chassis downstairs, hooked it all up and bolted down ( mistake ) I had I nice bright horz line, till I pulled it out again and stuck the old cap back in. :/

I do not see a short across it, but I don't have a real cap tester here, but have one at work, but it wont test leakage. :/

https://imgur.com/uk0D1qD

It's working OK now, still has IF alignment problems, which has to be fixed sometime I ever get my hands on a sweep generator, this also affects audio slightly ( buzz)

I will attempt to replace the caps/ diodes on the convergence PCB later in the week, which is the reason i have not put it all back together yet and back in place.

Worked with convergence PCB a bit last night, new diodes had very little / no effect, still can't get R/G at the top as good as left/ right/ bottom, ( perhaps never will, IDK ).
Moving the conv, yolk forward/ back a bit did not help much.
Have NOT tried the new caps in it yet, will try tonight to see if it changes anything.
The biggest problem I see is the R/G horz top lines are not linear, red above green in one side, and then green above red in the other, this is not seen anyplace else, the R/G can ALMOST be lined up, but is slightly still off.

Worked with convergence PCB a bit last night, new diodes had very little / no effect, still can't get R/G at the top as good as left/ right/ bottom, ( perhaps never will, IDK ).

Moving the conv, yolk forward/ back a bit did not help much.

For the heck of it, check where all the wires connect to the conv. yoke coils. There was a similar problem one time, caused by one of those wires being broke right at the connection point.

caps replaced, Resistors ( normal not adjustable seem OK )
only slightly better.
https://imgur.com/Qs1PUZS
https://imgur.com/jtYPypZ
https://imgur.com/rcdsYk4

aside from replacing potentiometers, there is not much more that can be done,

It's pretty close for such an old set.

Is the R/G vertical left potentiometer at one end of its range?

If so, have you tried setting the R/G vertical left potentiometer to center, then adjusting the R/G vertical right coil, then readjusting the R/G vertical left potentiometer?

Is the R/G vertical left potentiometer at one end of its range?

If so, have you tried setting the R/G vertical left potentiometer to center, then adjusting the R/G vertical right coil, then readjusting the R/G vertical left potentiometer?

the only one at the end of range is r27 R-G vert lines top ( not replaced ) X6 r270 new
adjusting will NOT get it in range
R26 does work on the bottom.

all other adjustments seems to have normal range

Have you checked C4 and R106, that couple the vertical waveform from the cathode of the vertical output?

Have you checked C4 and R106, that couple the vertical waveform from the cathode of the vertical output?


I replaced C4 a long time ago, when i replaced the majority of the electrolytics, r106 is still original. that may be it :(


edit--

yeah, and the damn thing would have to be hidden under the chassis:yikes:

not going to be changing any time soon, don't wanna pull it out a 3rd time in 1 week.

Somehow I always get lucky with convergence on these old sets. Never had to get into the convergence board. Knock on wood. My CTC16 seemed to converge well with your same oddball issue. R27 r/g vertical top is almost at the end of its range but able to achieve good convergence.

I replaced C4 a long time ago, when i replaced the majority of the electrolytics, r106 is still original. that may be it :(


edit--

yeah, and the damn thing would have to be hidden under the chassis:yikes:

not going to be changing any time soon, don't wanna pull it out a 3rd time in 1 week.

I remember when I started restoring color sets with my CTC15 and hit the troubleshooting stage that 3 chassis pulls in a day was a low number.... Tip: there are a couple of screws or holes for them on either side of the power cord interlock , and there should be a matching set of half circles on the tuner/control subchassis. They are for bolting the subchassis to the main chassis to make pulling and installing the chassis for short tests easier.

I remember when I started restoring color sets with my CTC15 and hit the troubleshooting stage that 3 chassis pulls in a day was a low number.... Tip: there are a couple of screws or holes for them on either side of the power cord interlock , and there should be a matching set of half circles on the tuner/control subchassis. They are for bolting the subchassis to the main chassis to make pulling and installing the chassis for short tests easier.

https://imgur.com/Txm8oBx

If you look closely at it when I had it on the bench last week, I had the tuner there while I was working on it, till I removed it to hook up the bar-dot input.
Nevermind that I like to add new parts ( caps & such ) with silicone :p as long as it can't be seen from above!

New r106 & c4 ordered , replacing c4 again, as it was not EXACTLY @ 50 uf, but a bit higher, that may or may not also be an issue, this time, getting precisely what it says on SAMs is a replacement , 75-TVA1414-E3.

In no big rush to replace them, so using ultra cheap shipping from Mouser, $3.30 vs $7.50, meaning rather than get it tomorrow, it will be here Sat.
Will stick the back on it for now and wait for another weekend to put them in.

Which does bring up a un-related topic, the 2 metal clips for the back have been missing since forever, what can be used in their place? :o

The resistor info for the resistor off the vert out cathode is a bit confusing.
The SAMs schematic shows r106 to be 5.6k 3w, with alt parts of irc resistor pw5-6000 6k 5 watts, & workman 3g-5600 ( 5.6k 3w)

The CTC-16 (not x) shows it to be 5w. :o
both have the same RCA part # for the resistor, 104180.
But the SAMs for the XL clearly shows 3w, and lists a part # shown on others listed as 5w, so what is in it? Does it not matter?


edit---
https://imgur.com/UbSRwgB
what i find so confusing
r106 vs 105 16xl- 16
same location on schematic, shows same RCA part number, why is one 5w and one 3w :o

The resistor info for the resistor off the vert out cathode is a bit confusing.
The SAMs schematic shows r106 to be 5.6k 3w, with alt parts of irc resistor pw5-6000 6k 5 watts, & workman 3g-5600 ( 5.6k 3w)

The CTC-16 (not x) shows it to be 5w. :o
both have the same RCA part # for the resistor, 104180.
But the SAMs for the XL clearly shows 3w, and lists a part # shown on others listed as 5w, so what is in it? Does it not matter?


edit---
https://imgur.com/UbSRwgB
what i find so confusing
r106 vs 105 16xl- 16
same location on schematic, shows same RCA part number, why is one 5w and one 3w :o

If you can't spec the same wattage resistor always go up in wattage not down...they probably did that.

Also when replacing a high watt power resistor that tends to get hot in a restoration scenario it may be better to choose a higher wattage part than original as that will make the replacement run cooler.

If you can't spec the same wattage resistor always go up in wattage not down...they probably did that.

Also when replacing a high watt power resistor that tends to get hot in a restoration scenario it may be better to choose a higher wattage part than original as that will make the replacement run cooler.

How does using a larger wattage resistor make it run cooler when the exact same wattage will be dissipated in it based on the usage? Other than the larger wattage resistor may or may not have slightly more surface area (unless you are changing to a chassis/heatsink mounted type or greatly increasing the physical size), it will run at the same temperature. The thermal resistance in free air will not be that much different and that, along with the watts dissipated is what determines the temperature.

i will most likely stick a 5w in there, no matter what is/was in there, i just find it weird that both the 16 and the 16XL show the same RCA part # in SAMS, but have different watt values, one would think the 3 watt one would have one RCA # and the 5watt, another, who knows what they were thinking 50+ years ago :O

How does using a larger wattage resistor make it run cooler when the exact same wattage will be dissipated in it based on the usage?
For a given wattage being dissipated, x amount of heat is being dispensed thoughout the entire mass of the resistor. The greater the mass, the lower the temperature of a unit volume of that mass. Ergo, a larger mass runs cooler. Er, at least that's my hillbilly take on it. :D

For a given wattage being dissipated, x amount of heat is being dispensed thoughout the entire mass of the resistor. The greater the mass, the lower the temperature of a unit volume of that mass. Ergo, a larger mass runs cooler. Er, at least that's my hillbilly take on it. :D
Mass has nothing to do with terminal temperature. Mass will affect the rate of change of temperature, but thermal resistance is what determines the terminal temperature. Thermal resistance is affected by material, surface area and air flow. A larger mass will make it take longer to reach its final temperature, but that temperature will still be the same.

Mass has nothing to do with terminal temperature. Mass will affect the rate of change of temperature, but thermal resistance is what determines the terminal temperature. Thermal resistance is affected by material, surface area and air flow. A larger mass will make it take longer to reach its final temperature, but that temperature will still be the same.

Higher watt resistors typically have more surface area and thus run cooler...this goes for both chassis mount and non-chassis mount types.

A resistor of a given material typically gets rated by the amount of watts it can continuously handle without burning up or changing value (minus some percentage for headroom/safety). If the power put in is less than the power leaving that energy stays with the part and makes it hotter. If we concern our selves with a single resistance value and consider resistors of the same composition but different wattage rating, then obviously the higher rated part has a case that allows it to put energy into the air at a higher rate.
If a resistor is capable of putting thermal energy into the air at a higher rate than the circuit can supply it with energy the it will not store thermal energy and stay cool....
This can be proved empirically by taking a 1/2, 1 and a 10W resistor all of the same resistance connecting them in turn to a bench supply set to deliver 1W of power to them and observing how each responds over say 1 hours time...the 1/2W should over heat and burn open, the 1W probably get too hot to touch but remain stable and the 10W probably won't get noticably warmer than the ambient temperature of the room..... I've performed a version of this experiment before.

Mass has nothing to do with terminal temperature. Mass will affect the rate of change of temperature, but thermal resistance is what determines the terminal temperature. Thermal resistance is affected by material, surface area and air flow. A larger mass will make it take longer to reach its final temperature, but that temperature will still be the same.

But only in a hypothetical where the mass is totally insulated against radiative and convective cooling. In the real world, the larger mass, having greater radiative surface and more surface exposed to airflow, will end up running cooler than a smaller mass dissipating the same wattage. Seems like, anyhow.

OOPs. Electronic M already done it.

Tom
You just repeated what I said. Wattage rating has nothing to do with terminal temperature. Thermal resistance does. For example, modern metal film 1W and 2W resistors are smaller than older 1/2W carbon comp resistors because they are designed to run hotter (better materials) and do run hotter because they are smaller (higher thermal resistance). So in this case, a physically smaller resistor is a better choice for reliability even though it will run hotter at the same power dissipation as the larger 1/2W comp resistor.
If you want to state that a higher wattage resistor that is the same composition and much larger in physical size will run cooler, that is a true statement, but only because its thermal resistance is lower, not because its wattage is higher. The two are not absolutely related or interchangeable.

But only in a hypothetical where the mass is totally insulated against radiative and convective cooling. In the real world, the larger mass, having greater radiative surface and more surface exposed to airflow, will end up running cooler than a smaller mass dissipating the same wattage. Seems like, anyhow.

OOPs. Electronic M already done it.
Surface area is separate from mass. Just because something is higher in mass, it does not have to have more surface area. If you take a hollow tubular vitreous power resistor and fill it solid, you have greatly increased the mass, greatly decreased the surface area and greatly increased the thermal resistance. The resistor will then run hotter.

Tom
You just repeated what I said. Wattage rating has nothing to do with terminal temperature. Thermal resistance does. For example, modern metal film 1W and 2W resistors are smaller than older 1/2W carbon comp resistors because they are designed to run hotter (better materials) and do run hotter because they are smaller (higher thermal resistance). So in this case, a physically smaller resistor is a better choice for reliability even though it will run hotter at the same power dissipation as the larger 1/2W comp resistor.
If you want to state that a higher wattage resistor that is the same composition and much larger in physical size will run cooler, that is a true statement, but only because its thermal resistance is lower, not because its wattage is higher. The two are not absolutely related or interchangeable.

I was never trying to say that 2 different composition parts will have the same thermal resistance for a given wattage rating when you started arguing. Merely stating that if you are going with some wattage in a given composition part that choosing a higher one than necessary tends to reduce case temperature...You're very passionate about arguing an accurate generalization deep into the weeds.

I was responding to your original comment which was inaccurate and who's goal posts have now been moved several times. Sorry I wasted time on the forum. It won't happen again. Carry on.

I did not mean to start a huge fight T_T
I was just confused by seeing the same RCA# and dif watt values.

What i'd really like to know now is, where do you guys find all these vintage sets :o
I know i was was lucky to find my 16xl all those years ago and protect it.

but i really don't want to put the effort into the CTC-90 i have, it;s a weird model and solid state, but had a NEW CRT. if i could track down a CTC-17 (or something like) to play with, then i would find more interest for it.

I did not mean to start a huge fight T_T
I was just confused by seeing the same RCA# and dif watt values.

What i'd really like to know now is, where do you guys find all these vintage sets :o
I know i was was lucky to find my 16xl all those years ago and protect it.

but i really don't want to put the effort into the CTC-90 i have, it;s a weird model and solid state, but had a NEW CRT. if i could track down a CTC-17 (or something like) to play with, then i would find more interest for it.

There are plenty of places online where vintage TVs are for sale, there are also collector clubs for radios (also the ETF) and some places like antique stores and thrift shops where chances of finding sets are good.
You also, depending on where you live, may have to be willing to drive sometimes hours or wait years if you want something specific that isn't super common...Large old population centers where there was money when the sets were new and where there (are at least pockets where there) hasn't been a lot of population churn or redevelopment/modernization are usually places where people can easily find vintage sets locally...Places like Chicago, Milwaukee, Detroit, the larger cities on the east coast, LA, etc. seem to always have enough available to start a decent small collection in a couple months. Places like deep rural Idaho you might not ever find anything if you limit your search to a 2 hour drive.
Some of my better finds I had to drive around 6 hours 1 way to get...And a good portion of my collection has come from driving from Milwaukee to Columbus Ohio 1-2 times a year for the ETF meet.

BTW: don't sweat the little arguement. That is relatively mild in the context of what all I've dealt with over the years here (and I only slightly bothers me)...While by and large the TV community is a bunch of extremely good folks (and thousands of times better mannered than some internet message communities) I have met some bad apples, who have lied, picked fights with me, intentionally grabbed sets I was on my way to buy, cheated me out of money for things, etc, etc...The most sought after stuff (Pre-WWII, some early post-war models ad pre-1960 color) can bring out the worst in people when for sale, and some folks can be or come across as just plain rude (I've made that mistake) when correcting others on details or recieving corrections on their details.

That did not work too well. :(

I tried to wire in a IF section bypass switch at TP1 ( point B) by running a video wire from one end of L9 to a switch on the back of the set and back to the grid of the first video amp, so I could switch between Ext video and video from IF, but the Tuner video was too washed out/ weak, I guess the video lines too and back from the switch added too much resistance for the IF input to work correctly.

External input works great though!

Next time I have the chassis out, I will just have to stick a relay at that point to get it to do what I want, same with the Audio,

Right now with ext video, I tap audio into the volume control R1 at point 30,( V8 Removed ) but I have to boost it by several Dbs or it wont be loud enough , pulled down by inactive sound circuts through c53, I'm sure if I also put a relay to switch in audio and cut out that cap, I wont have to boost it so much.

That did not work too well. :(

I tried to wire in a IF section bypass switch at TP1 ( point B) by running a video wire from one end of L9 to a switch on the back of the set and back to the grid of the first video amp, so I could switch between Ext video and video from IF, but the Tuner video was too washed out/ weak, I guess the video lines too and back from the switch added too much resistance for the IF input to work correctly.
...

Not likely a resistance problem, but too much stray capacitance with the long wires. A relay would still be the fix.

Not likely a resistance problem, but too much stray capacitance with the long wires. A relay would still be the fix.

It's also probably best to get the right KIND of relay, power vs signal, though in this case may not be ultra critical, it still may make a difference. Choosing, Mouser 653-G5V-1-DC12 when I DO plan to do it, I already have the +12v from my video amp.

someone got lucky :(

https://www.ebay.de/itm/RCA-113992-Fly-278-CTC16-CHASSIE-/202797172756

I want one as a spare, just in case :/

I can see now see why these are better than the original RCA FBTs :o

https://imgur.com/4QcPFRc

But what blows my mind even more, is that it went for $75 and the seller did not overcharge for it:yikes:

but damn!
I check every month to see what is out there ... and that one sold on 10/20 :jawdrop:

I should check more often T_T

I can see now see why these are better than the original RCA FBTs :o

https://imgur.com/4QcPFRc

But what blows my mind even more, is that it went for $75 and the seller did not overcharge for it:yikes:

but damn!
I check every month to see what is out there ... and that one sold on 10/20 :jawdrop:

I should check more often T_T
The link was to German eBay so it probably sold within Germany to someone who likes to play with HV instead of a TV collector....

The link was to German eBay so it probably sold within Germany to someone who likes to play with HV instead of a TV collector....

Oh NO!!!

Oh NO!!!

The link was to German eBay so it probably sold within Germany to someone who likes to play with HV instead of a TV collector....

That would suck if that's how it really ended up, such a waste. :(
I wish I would have known back during all the years I had it in storage that the FBT was so prone to toasting itself, I would have gotten a spare when they were easier to find.
But at least now it is running very cool, so much I can't see it on infrared over the heat of the HV rect, and there is a big opening for airflow in the HV-cage, yippee ki yay!!! X-RAYS! :banana::smoke:

But w/o a spare, I will always have some degree of worry with it, the OEM may last, who knows, or it may not.:yikes:

That would suck if that's how it really ended up, such a waste. :(
I wish I would have known back during all the years I had it in storage that the FBT was so prone to toasting itself, I would have gotten a spare when they were easier to find.
But at least now it is running very cool, so much I can't see it on infrared over the heat of the HV rect, and there is a big opening for airflow in the HV-cage, yippee ki yay!!! X-RAYS! :banana::smoke:

But w/o a spare, I will always have some degree of worry with it, the OEM may last, who knows, or it may not.:yikes:

If it runs cool it will probably be fine.

Even the X-ray unshielded sets are not a danger unless you like to keep your body pressed up against the running set for hours on end...at normal viewing distance there should not be anything above background levels present.

Speaking of “dopey arrangement of the HV cage” as EM put it in the other thread, I got a bit too close to that silly plastic cap on the top, (with the wires coming out ) , covering the inverted tube socket for the HV-rect, and, POP-POP-POP-POP! The 24kv found it's way through the little wire hole to me.

Nothing new, I have felt this many times before over the years, I was a bit surprised that it found it's way out so easily though.
I guess I should put some silicone on top of the damn thing to make it harder to arc out, as I don't expect to open that cap any time soon.

Speaking of “dopey arrangement of the HV cage” as EM put it in the other thread, I got a bit too close to that silly plastic cap on the top, (with the wires coming out ) , covering the inverted tube socket for the HV-rect, and, POP-POP-POP-POP! The 24kv found it's way through the little wire hole to me.

Nothing new, I have felt this many times before over the years, I was a bit surprised that it found it's way out so easily though.
I guess I should put some silicone on top of the damn thing to make it harder to arc out, as I don't expect to open that cap any time soon.

If the hole ain't too big my first thought would be an accumulation of conductive dirt inside... I'd clean inside the cover (especially the wires) and see if I could draw an arc then if necessary silicone the hole.

+1 ^^

Didn't think of it at first, but putting silicone over an old carbon track is not the most permanent fix.

+1 ^^

Didn't think of it at first, but putting silicone over an old carbon track is not the most permanent fix.

There is no real “carbon track” per se, it's most likely as EM. Mentioned, fine conductive dust, as what happened is, I was reaching in the set while on, bumped into the HV wire a few inches above the cap, and the arc leapt from the lug inside under it, through the wire hole, ran up the wire to my arm!

It was exhilarating and surprising at the same time!:banana: :yippy:

I think I will try 1 more time to replace C70 next time I have the chassis out, (last try I lost vert sweep for some reason ), this time I will try this cap, 80-A72UK1100AA00K , perhaps it will work better than the last try, otherwise, I will put the old one back. :/

I think I will try 1 more time to replace C70 next time I have the chassis out, (last try I lost vert sweep for some reason ), this time I will try this cap, 80-A72UK1100AA00K , perhaps it will work better than the last try, otherwise, I will put the old one back. :/

Looks valid but mouser claims non-stocked with a 45 week lead time......if it takes a year to get I'd probably chance a ceramic instead... worse case scenario probably shouldn't be worse than the first part you tried, best case scenario it works good and you've eliminated the Elmenco bleached dynamite stick.:scratch2:

Looks valid but mouser claims non-stocked with a 45 week lead time......if it takes a year to get I'd probably chance a ceramic instead... worse case scenario probably shouldn't be worse than the first part you tried, best case scenario it works good and you've eliminated the Elmenco bleached dynamite stick.:scratch2:


I did find another source, i just have to buy 2 :(

new caps and resistor for vert installed, this time it worked :o

https://imgur.com/DDkHAgX

also, relay for video IF installed,
https://imgur.com/DHvE5AQ
https://imgur.com/vkuFTtr

will put one in for Audio tomorrow.

One trick for adding a modern relay to a tube set (transformer type only) without mounting an additional power supply is to use the heater line as a relay source. If the relay is 6VDC or less a single diode or bridge rectifier and a 16-25V 220-1000uF lytic will do (if 6VAC just connect direct), for a 12VDC relay use a couple of diodes and a couple of caps in a voltage doubler circuit...For a higher voltage relay either go 110VAC and use the line input or go under 12V.

Both relays are in and working, I need to tack them down a bit more for wire safety, ( the glue I had was too old :( )

The" Elmenco bleached dynamite stick." is replaced and working OK now.

C4 & R106 now replaced with EXACTLY what the SAMs says.
I used to have the old R106 and a 56UF (called for 50uf) now has one listed as exact replacement, and replaced old 5.6k 3w R106 with a new 5w one.
however, after all this, it still has made no difference in not being able to get the r/g vert lines at top to line up perfectly. :/
still looks like this.
https://imgur.com/jtYPypZ
can't get closer.

I have tried diff placements of the conv yolk , still same in the end.
not sure what else to try. :scratch2:

Wild stab: have you checked rectifier X6 and the parallel resistor R217?

Wild stab: have you checked rectifier X6 and the parallel resistor R217?


they're both brand new, however, i did try putting in a resistor that was 30 ohms over the 270 ohms that was supposed to be in place in R217, after playing with it a bit, got this..
https://imgur.com/NFbWk5S

i will try to get a better pic later :o

Wow!

It doesn't get much better than that on a roundie. Good job!

I still cant help but wonder what is causing the slightly annoying retrace lines to show up sometimes.

CRT age? No idea, the bias is at lowest setting, did grayscale setup a million times, no help. Will still show up when I turn up brightness high on some scenes, no matter the video source ( NOT macrovision )
Other than that picture is fine.

Still not quite sure how the horz blanking works yet. :/
VERY strong horz pulse from FBT on grid 230v @ -80v dc (on my TV ) , shows 115v on plate, goes to CRT bias switch and .22 uf to the Y amps. Shows it to be 15v on SAMS on bottom of tree, ( was 8-9 max on mine )



This is what I find a bit confusing and don't quite get, the Cathode of the blanking amp ( Cathode follower? ) is tied to the cathode of the bandpass amp.
Shown to be at 5v, no other info ( waveforms )

no cap or resistor on the blanking amp, but the bandpass has a 820pf 10% and a 390 ohm res, both replaced by the person before I had it.

I have seen no color problems since I got the color to work, and I DID check the resistor and the value of the cap looked OK, but I did not make sure they were exact.

Now since I really do not understand the circuit, I wonder, could this resistor / cap effect the blanking amp?
YES the 6gu7 is new, the 6gh8a is not.

I have looked at the horz blanking setup in the CTC 10/15/16/16XL/20 , and it very much looks like they use the same setup in all of them, with only slight variations.

Making a guess on how it works, using pulses from the FBT, (on the grid) it then passes the blanking pulses via a .22uf to the cathodes of the RGB-Y amps, tied to gnd with a power resistor at the end of the chain, wave can be anything from 10-15, depending on the set.

It also seems to pass blanking pluses to the cathode of the color bandpass amp (cathode follower setup), this is tied to gnd via 820pf / 390 ohm res, (all versions )
This I assume is to insert blanking to chroma, where the above is for luminance?
Only the CTC-10 shows what the wave is on the cathode, (10v ptp ), I will assume this is the same for all sets , or rather close, since they all have the same circuits.
https://imgur.com/yCoszDQ

At this point, I do not remember what the waveform was like at that point on my set, but as mentioned, I did not replace the 820pf / 390 ohm res off the cathode of my bandpass, as they were before I got it, but now I think I may try next time I have it apart & perhaps r188 (power resistor at end of -y amp chain) .

This also may get me nowhere, but I have replaced pretty much everything else in the blanking circuit.

Granted, I don't see the lines as much as a real problem right now, more of an annoyance.

:banana::banana::banana::banana::banana::banana::b anana::D:D:D:D:D

HOLY CRAP I GOT ONE!!!!!!!!!

https://www.ebay.com/itm/RCA-113992-Flyback-Transformer-/223675445766

Just happened to be in the right place at the right time, and BOOM! , it was there!

Yes, it's for a CTC-16 and not a 16XL, but the diff can be adjusted for when needed!

:banana::banana::banana::banana::banana::banana::b anana::D:D:D:D:D

HOLY CRAP I GOT ONE!!!!!!!!!

https://www.ebay.com/itm/RCA-113992-Flyback-Transformer-/223675445766

Just happened to be in the right place at the right time, and BOOM! , it was there!

Yes, it's for a CTC-16 and not a 16XL, but the diff can be adjusted for when needed!
Congrats on your newly acquired hens tooth. :thmbsp:

Your next mission should you choose to accept it is to acquire unobtainium. :D
This post will self-destruct in 10seconds.

:banana::banana::banana::banana::banana::banana::b anana::D:D:D:D:D

HOLY CRAP I GOT ONE!!!!!!!!!

https://www.ebay.com/itm/RCA-113992-Flyback-Transformer-/223675445766

Just happened to be in the right place at the right time, and BOOM! , it was there!

Yes, it's for a CTC-16 and not a 16XL, but the diff can be adjusted for when needed!

I just saw the eBay listing for that flyback, and was amazed. $150? For just one color TV flyback transformer? That fly must be incredibly rare if the seller wants that much for it; that, or else the seller wants to get as much money as he can from the sale (the latter, unfortunately, is quite common on eBay; I have seen ridiculously high opening bids for 1950s-'60s TVs and radios, and cannot help wondering how the seller manages to sell the set, if he or she ever does). I could see paying that much for a flyback if the TV it goes with is very old and/or rare, but the RCA CTC-16 is from the mid-1960s, so replacements for any of its parts, including the flyback, shouldn't be anywhere nearly that expensive.

I just saw the eBay listing for that flyback, and was amazed. $150? For just one color TV flyback transformer? That fly must be incredibly rare if the seller wants that much for it; that, or else the seller wants to get as much money as he can from the sale (the latter, unfortunately, is quite common on eBay; I have seen ridiculously high opening bids for 1950s-'60s TVs and radios, and cannot help wondering how the seller manages to sell the set, if he or she ever does). I could see paying that much for a flyback if the TV it goes with is very old and/or rare, but the RCA CTC-16 is from the mid-1960s, so replacements for any of its parts, including the flyback, shouldn't be anywhere nearly that expensive.


Yes, I'm well aware that it is very overpriced, however, the 16 type FBT is one of the hardest to find anywhere, be it RCA, Thordarson , TRAD , or any of the other substitute make, used or new,
I had been looking for a year and a half for a spare, all over, and when I found this, I could not let it go!

and it has arrived!
https://imgur.com/uLnQnvP
https://imgur.com/M6SRgo5
and I did a brief test, and it IS new and good resistance wise, as what it should be on SAMS.
Chose a bit of Jay and Silent Bob Strike Back DVD to display for the test along with the ugly macrovision :(

When it comes to replacing the old with this one and it IS when and not IF, as it will happen sooner or later,
I already have a solid state focus rect, so why not go solid with the HV one when I replace the HOT?
with something like perhaps http://hvstuff.com/100ma-30kv-100ns-high-voltage-diode-hv-rectifier-high-frequency

thus remove all heater loads from the FBT.

That diode would probably work. You Could also get an IIRC R3A3 which is a plug in solid state replacement for the tube HV rect. They haven't been made in decades but some NOS are still hanging around.

When it comes to replacing the old with this one and it IS when and not IF, as it will happen sooner or later,
I already have a solid state focus rect, so why not go solid with the HV one when I replace the HOT?
with something like perhaps http://hvstuff.com/100ma-30kv-100ns-high-voltage-diode-hv-rectifier-high-frequency

thus remove all heater loads from the FBT.

I replaced a couple of hundred CTC16 flys back in the day, and I recall the big rush was in summer months when heat and humidity got to them. Most of the ones that failed were from arcing from the 3A3 socket to the core - humidity related.

I honestly don't know how much you will gain by using a SS rectifier to reduce heater loads. I would guess it's probably a half watt of heat saved overall.

Unless you're going to run this 8 hours a day from now on, and do so in hot humid weather, I really wouldn't worry about saving the heater load on the fly.

Tom pointed out a SS stick rectifier drop in replacement for the 3A3. Dad used one on our CTC9 and lasted for about 10 years before the tube went and we scrapped it. I believe International Rectifier made it.

John

The CTC-16 and later style flys with the HV rect top cap integrated into the HV winding would also develop conductivity in the rubber covering the winding (shango66 has some videos on the subject). I don't recall if this was done but I recommend and tend to remove that rubber cover and replace it with sensor safe automotive RTV silicone.

The CTC-16 and later style flys with the HV rect top cap integrated into the HV winding would also develop conductivity in the rubber covering the winding (shango66 has some videos on the subject). I don't recall if this was done but I recommend and tend to remove that rubber cover and replace it with sensor safe automotive RTV silicone.

The current FBT in there is still all original, no mods, I probably won't mess with it until something happens to it, then change to the NOS one and take time trying to fix it, if it can be.
The only other main point of failure now would be the CRT, but as mentioned, this TV is a bit unique with regard to others of it's kind, as it has spent more of it's life in storage (20-25 years) than being used, so there is less usage on the CRT.

The current FBT in there is still all original, no mods, I probably won't mess with it until something happens to it, then change to the NOS one and take time trying to fix it, if it can be.


Tom and I were actually talking about the same thing. Most of the flys arced from the 3A3 cap socket to the core through the outer covering. A few would show a blackened area through the donut denoting a shorted turn.

Back when these TVs were everyday runners, a lot of people would let the TV run when it started arcing, maybe thinking it was antenna interference and wouldn't shut them off until the telltale smoke and stench appeared. By then it was often too late. I would see them with a totally smoked flyback and a burned 6JE6.

It's unlikely you or any collector will leave this TV running unattended or not immediately jump to your feet to shut it down if you hear arcing and see the distress in the screen. At that point, you can cut the outer red jacket off the fly where it arced through, clean it thoroughly, dry it, and put on the sensor safe type RTV (regular RTV will cause corrosion from the acetic acid).

If it were mine, I wouldn't use the new fly unless the original couldn't be salvaged.

John

That NOS FLY is money in the bank. If you ever sell the TV, don't include but sell that replacement fly separately.

Another VK member sold me a badly needed NOS Thordarson fly that he never used, for a similar price.

That NOS FLY is money in the bank. If you ever sell the TV, don't include but sell that replacement fly separately.

Another VK member sold me a badly needed NOS Thordarson fly that he never used, for a similar price.

I don't ever plan on selling it :p
I did not hang on to it for so many years in order to ever let it out of my ownership! :D

I just wish I could go back in time and save the CTC-10A that my father wasted... :yikes::no:

I thought WTH, i have mentioned this before, but never really SHOWN IT.

https://www.youtube.com/watch?v=Oaw7LDRBB5c&feature=youtu.be
I do not consider this to be a real problem, just something rather endearing to this set, for it has always done this since I got it, and it does it not matter if there if no RF input of a good strong signal.

I do wonder sometimes WHY it does it, and if other RCA sets do it also.

Since the IF section on it was jacked up by who ever had it before me, I have put A/V bypass relays in the set, and the sound on this id bypassed right out of the detector 6HZ6 far side of C53, (point 30 ) for external audio by the flip of a switch, and I have noticed it does not do it with external audio.

It's odd, what ever it is! :p

I have noticed a slight ghosting problem with my CTC-16XL, very much like seen in this thread,
http://videokarma.org/showthread.php?t=265940

I can say right now however, this is NOT a tuner/if problem, because it is seen with both RF input and on bypass/ direct AV input, so I'm already suspecting the old delay line, I had already been wary because it looked rather raged and abused to star with (beat up, tape peeling off, etc ), but like other things, I deem this a minor annoyance, and will be looked into later.
This may or may not be related to the other minor problem of shadowing on the screen of bright text/ letters.

Things I intend to do to try to address this is replace both the 1st/2nd video amp ( 6lf8) and video output (12by7a ), they are a bit old, and I'm not sure how up to par they are, I'm sure that NOS tubes would help.
There are still a few film caps in the circuit that are original, they say they don't go bad, but who knows, they may have degraded a bit, so it won't hurt to replace.
And as mentioned before, all resistors on the color PCB were replaced before I got the set, and checked by me, so they are OK.

A delay line problem will be tricky to deal with I'm sure, ( repair/replace? :o )
It should be easy enough to bypass it from the top w/o removing the chassis, that will at least tell me if my guess is right, if it is then what to do... :(


One thing to try, but I'm not sure what effect it will have on the old delay line, will have to try and see, wrap with layer of kapton tape first, then copper tape over that, with ground wire soldered to both ends, and then another layer of kapton tape over that. And see how it behaves.
If it's still acting up, there is places to get a NOS one, but I'm not exactly sure which one to get if I have to resort to that. :(
https://www.vivatubes.com/nos-nib-miller-7616-delay-line-6-lgth-375-diam-tv-radio-amp-parts/
They have many to pick from, and I'm not sure which is right for my 16.
But at least, if it is the old delay line, there is a way to get a replacement.

But as i said, this will be looked into later.:yes:

Bypassing is a good first test.

Wrapping an additional layer of copper tape:
If the outer layer is a ground layer already, this will not help UNLESS the existing layer is bad somehow (or disconnected from ground).
If there is no outer ground layer on the original, adding one will mess things up, as it will lower the impedance (producing transients) and increase the delay. (UNLESS the underlying layer is bad or disconnected, in which case an added outer layer may fix it).

Regarding caps:
Film caps are generally too large in value to cause short video transients, unless they are meant to be bypasses and are open. Transients can be caused if smaller capacitors or peaking coils associated with the delay line are bad.

Regarding replacement delay lines:
Delay lines are designed for a specific impedance, obtained by the number of turns per inch, their diameter, and the capacitance per inch determined by the copper ground sheet or sheets (under and/or over the windings). So the best bet is to get one from the same TV chassis number. Second choice would be to look for one of similar dimensions, although this wouldn't guarantee the winding count.

Bypassing is a good first test.

Wrapping an additional layer of copper tape:
If the outer layer is a ground layer already, this will not help UNLESS the existing layer is bad somehow (or disconnected from ground).
If there is no outer ground layer on the original, adding one will mess things up, as it will lower the impedance (producing transients) and increase the delay. (UNLESS the underlying layer is bad or disconnected, in which case an added outer layer may fix it).

Regarding caps:
Film caps are generally too large in value to cause short video transients, unless they are meant to be bypasses and are open. Transients can be caused if smaller capacitors or peaking coils associated with the delay line are bad.

Regarding replacement delay lines:
Delay lines are designed for a specific impedance, obtained by the number of turns per inch, their diameter, and the capacitance per inch determined by the copper ground sheet or sheets (under and/or over the windings). So the best bet is to get one from the same TV chassis number. Second choice would be to look for one of similar dimensions, although this wouldn't guarantee the winding count.

Most CTC-RCAa seem to have the same delay line 15/16/16XL have part #109837 and that site posted above most likely DOES have it, but I have been unable ( so far ) to find a cross reference to that # there HAS to be a Miller cross to RCA #109837, I just dot know how to find it :(

but as mentioned, I will try the tubes first :) I still am not allowed to lift above 15lbs yet, and I'm guessing its the line cause of how ugly it looked, and guessing I won't be able to fix it.
Who knows, I may be able to, the grounding may be lose on it, and may be able to be patched, but if not, I would like to know which new one to get.

As for the caps, i have mainly 2 in mind.
https://i.imgur.com/fnlu7ZN.jpg
C23 & C25

C23 is one of those elenco tube BOMB capacitors that has given me trouble in the IF section ( took it out once ) and C25 is an original orange drop, I have found them to be leaky in the set before, not many, but a few, mostly ones close to tubes.

Will just have too see how things go

C23 is small enough to cause video response effects, but C25 is large enough to carry all video frequencies and be essentially a short circuit at the frequencies involved in the transient. If it were open, you would have greatly reduced contrast.

yanked the back off yesterday to touch up convergence, it was off a bit.

https://i.imgur.com/ppZ7BnW.jpg
you can see the slight shadowing to the right, not TOO bad, but its there.

will most likely have to take a close look at the delay line grounding next time o take the set apart.

still can't find a cross ref number for it :sigh: :tears:

https://i.imgur.com/d15IVcY.jpg

live video,, hard getting a good shot with this cellphone still :/

the brats got bored watching me play with the set. :O

https://i.imgur.com/SkofrHv.jpg

Off-air pic is too blurry to see this kind of stuff.

Worth checking grounds, but it's likely the delay line and its grounds are OK, and you are seeing a combination of multiple effects that are normal

Possible contributors
1) using a crosshatch signal generator - signal spills all over the channel, has no phase compensation like a commercial transmitter, transient response varies with fine tuning
2) chroma trap ringing
3) delay line load impedance not perfectly matched, line has some phase distortion not perfectly compensated by the load coils
4) sound trap ringing, made worse by the bar generator splattering a lot of energy into the sound area
5) other IF response effects

(2), (3) and (4) may be within normal tolerance for this chassis, and may be less visible with a properly filtered commercial modulator. VCRs, DVD players and digital TV converters have no video phase slope pre-compensation as required by FCC rules for commercial transmitters. One would hope they had at least luma/chroma delay alignment to match the FCC requirement at chroma center frequency, but that was/is often not the case. (PAL did not use transmitter pre-compensation, intending for any chroma edge distortion to be cancelled by the PAL decoder.)

To separate video from IF issues, turn the fine tuning - if the rings move, it's IF, otherwise it's video (detector, 4.5 MHz trap/take-off, and following video circuits)

https://i.imgur.com/yuZEQZP.jpg

best pic i could get

Sometimes I'm surprised that the set works as well as it does, cause it WAS in the hands of a mad tweaker who made a mess of it before I got it.

And it took me forever to figure out why I was getting no color through the tuner but could with fed in video, and that was the 4.5mh trap was so far out of tune, it was blocking color.

IF needs alignment, because I know it was messed with, hell the entire set could use an end to end alignment but I don't have the equipment or know how to do it.

Example, I know for a fact that the color takeoff coil and bandpass coils were replaced and never adjusted , just left at the pre-set from RCA.

I will look at stuff next time I pull the chassis , but there may not be a lot I can do. :tears:

My philosphy is "fix the obvious things first." In your case, the obvious is what you have mentioned about things being untweaked or madly mis-tweaked. The delay line is basically working, so that becomes a second priority to check. Plus, as I said, sets are never perfect when properly aligned anyway, due to component tolerances.

Well, I know it can do better, but I'm basically stuck in a position that I can do little about it due to lack of exp/ equipment.
Unless there is someone in the general area who has the equipment and knows how to align it, it will have to stay like it is. :(

I do plan to pull the chassis sometime to replace the 6meg focus resistor and 130pf cap, not that they are really failing now, but I'm sure that they are worn and could use replacing.
I have always wanted to look into to a retrace line problem this set has, where as all resistors on the color PBC have been replaced, the ones on the sweep PCB have not been, there is a 100k resistor on the sweep PCB that is old that I suspect to be out of tol, it's tied directly to the plate of the vert output tube and transformer, and thus being hit by very large vert pulses, it then goes to a .01 ceramic disc cap, (not suspect) , then a 68k resistor (new) , then to the plate of the video output tube, thus the source of vert blanking, I overlooked this last time I had it apart, and was looking mostly at horz blanking. :(

Step by step, I'll try to make this set work the best I can.
It has come a long way from a set that was in pieces, with it's non working color PCB hanging out by it's wires, cover to the IF section removed and lost, and most original screws gone then stuck in storage for many years! :)

yup, I was right!
https://i.imgur.com/i7CqJ42.png

Added to the to-do list,
it checked at 120k almost.
was easy enough to check, pull the vert tube, VOM at pin 6, and point 52 is right at the back of the color PCB at the back of the chassis, easy to reach.
I will most likely replace C31 while I'm at it, even though it prob OK, and hopefully the retrace lines will be all gone after that, and at least THAT annoyance will be addressed,

I would still like to try bypassing the delay line, but the question is, how to go about doing it w/o disturbing anything, been thinking about this for a few days now.
I don't want to A) remove the chassis yet, or B) remove the cover of the IF section where the 1st/2nd video amp tube is, and this is what I'm thinking of doing, and I want to make sure it sounds right before I try it, IE, I don't want to let any magic blue smoke out. :tears: :no:

https://imgur.com/fnlu7ZN

re-using old pic, ignore red circles.

Remove V4, wrap kapton tape around metal shield on tube, leaving space on bottom for ground tab, wire wrap piece of magnet wire to pin 3 of V4, secure magnet wire with kapton for safety, connect magnet wire to junction of of C25 & R66, bypass complete.
This also leaves out L13, 72uh coil, I could add in one of the extra coils I have laying around, but I'm not sure if it's really needed.
I'm pretty sure that doing this won't blow anything up, but I'm not %100 sure.:scratch2:

This should work, as the delay line and L13 are essentially a DC short. Don't bother trying to replace L13, it's purpose is to improve the transient response of the delay line, which you are bypassing anyway.

The dangerous part is connecting to V4 pin 3 carefully so as not to short to adjacent pins.

If the cover is not soldered in place, I would try doing this with the cover removed first, see what you get, then decide if you really need to do this with the cover in place.

Did you try the fine tuning yet to see if the transients move or are stationary? If they move, then you know it's an IF alignment issue and not the delay line.

This should work, as the delay line and L13 are essentially a DC short. Don't bother trying to replace L13, it's purpose is to improve the transient response of the delay line, which you are bypassing anyway.

The dangerous part is connecting to V4 pin 3 carefully so as not to short to adjacent pins.

If the cover is not soldered in place, I would try doing this with the cover removed first, see what you get, then decide if you really need to do this with the cover in place.

Did you try the fine tuning yet to see if the transients move or are stationary? If they move, then you know it's an IF alignment issue and not the delay line.

That's sort of two fold, in RF input mode, there is shadows that move with fine tuning, but are mostly seen in the color, if color is turned down, no shadow movement is seen, but there is a shadow also seen in the luminescence that does not move. This is also seen in direct A/V input.

I have known about the set having IF problems that had an effect on the color ( mostly red ) thus set the auto bypass circuit in it via a signal relay at TP1 Point B, direct input does look much cleaner, but still has the same shadow to the right as IF input, if I ever can get the IF aligned correctly someday I can remove the mod. :(

Shorting it won't be an issue really, :)
I essentially have an exact copy tube in the GE CTC-15ish clone, that I can take to work and rig up under microscope and make sure it's OK before I put it in.

...if color is turned down, no shadow movement is seen, but there is a shadow also seen in the luminescence that does not move. This is also seen in direct A/V input...
OK - definitely in the video section then.

AHHHH! I just found something I missed before, even though the 1st/2nd video amp tube has the shield on it, it is NOT being grounded.

the tab must have broke, or bent and I missed it.
gonna have to fix it.
No telling what kinda mess it could be causing...

Delay line bypass rig made, will try it this weekend.

https://imgur.com/IwoAhCB

grounding the shield did not make much of a difference. :no:

AHHHH! I just found something I missed before, even though the 1st/2nd video amp tube has the shield on it, it is NOT being grounded.

the tab must have broke, or bent and I missed it.
gonna have to fix it.
No telling what kinda mess it could be causing...
I hope that improves it for you. I know what it is to go after issues one at a time and when you see little to no improvement with each one, but they do add up.

The 21" Zenith I restored was that way. Original trouble started with a shorted sync/sound detector diode (not before sending me on a journey through the Zenith-unique sync circuit) and extreme vertical and convergence issues, which I learned alot from.

At the beginning, I could not imagine it ever being Zenith-bright/sharp. After several weeks, looking back made me realize how easy one could give up before its working as it should. Its just physics!

Well, the bypass idea did NOT WORK! :no::tears:
fail BIG TIME!!

https://i.imgur.com/6P12EZj.jpg
caused an echo image, which was ironically at about the same place that I had be seeing the shadow image, so who knows, it may BE delay line related, I will have to wait till the next time I have the chassis out to know for sure, I still wish I i could find a NOS Miller cross reference chart someplace, as IF i have to replace it, I'm sure that site has one I'm just not sure WHICH one,

In the mean time, I'm gonna work on what I CAN do w/o pulling the chassis, as in getting the convergence as perfect as I can, I made a few mistakes in placing the parts on the, CRT neck, but it did not seem to matter much, I still cant get it the way I like it, I may never will, there are some original resistors on the convergence PCB that I intend to change next, that may help.

Aside from that, there is a moderate list of minor annoyances to hit next time I pull the chassis... heavy sigh! :tears:

D'oh. Now that I look again, this is to be expected because the delay line is not driven from a low impedance (cathode), but high impedance (plate). To do the check you wanted to try, both ends of the delay line should be disconnected and then the jumper put in its place. You are seeing multiple reflections in the delay line when it is still attached.

If the shadow image without the jumper is at the same spacing as the one you see with the jumper, that is the same triple transit effect. This circuit does not necessarily terminate the input of the delay line correctly. Therefore, if the output termination is not perfect (or the delay line impedance is not nominal at all frequencies), some energy may be reflected back to the input and will not be damped there and will reflect again and return back to the output ("triple transit").

This tells you that if none of the components are out-and-out defective, the set may be operating within factory tolerances, and they all were subject to a bit of triple transient effects.

At this point, the delay line is no longer very suspect. Instead some trial and error variation in the output load components may improve things. L13, L14, R63, R64, and maybe L15 can all have an effect. But don't be too surprised if you find that you can't make it much better, and mainly worse. The fact that R64 is the only 5% resistor in the area is a hint. You could try tuning the L's (to larger inductance only) by bringing a core or some iron on a stick next to them. If you had a stock of peaking coils, you could try various values.

more: You could try replacing the peaking coils even if none of them are open, in case they have shorted turns instead. But I don't know if that was ever a common failure mode.

I do know for a fact that the delay line was roughly handled when I got the set, I'm not sure if it was really damaged or not, but it was NOT treated well at all, left hanging loose with only the IF end connected, I wish I had pictures of it, it took me quite a while to work out where all the loose wires to the color PCB went. :tears:

however, L13 was damaged, ceramic broken on the leads, more than ½ way, but still had continuity, so I assumed it to be OK and suck silicone on it and put it back in.
This may be a source of a problem, no idea, :( but as luck would have it, I have just found an exact replacement for it, and will come who knows when :/

Another possible problem. however I doubt it, that when I put it together, I had no real visual reference on HOW to do it, unlike I do now.

example, how it's done in the GE RCA clone, https://i.imgur.com/FxjBWaj.jpg

you can clearly see the heavy wire going down that is grounding the delay line, in my CTC-16, that was GONE! all that was there was the grounding solder point on the DL, and since I was unsure where to ground it to, i used a piece of wire ( not as thick as seen in the pic ) that runs to a ground point to the ends on the color PCB.

I doubt that this is a problem, but who knows :sigh:
Is the DL damaged , no way to tell w/o getting it out and looking at it under a scope :/
there has to be some way to find a cross for it, if it is.

As for the peaking coils, some of those oddball sizes will be hard to find. :tears: I got lucky with L13 (72 uh ) who knows, may get lucky again! :D

Grounding the delay line differently than originally could cause some trouble.

It would be reasonable to use series combinations of more readily available coil values to make a replacement for the odd peaking coil values. The specification of odd values is a hint that they may be critical, just like the 5% resistor.

Peaking value coils are never critical. In fact, its sort of silly worrying
much about just the value, unless you can get a for certain absolutely exactly original
factory model coil.

You see, these thing have capacitance across them and thus are parallel tuned circuits. Whether they are used in series with the signal or as a plate load, that resonant frequency matters.

And the "standard replacements" listed are often, while close in low frequency
inductance, way pff in parallel resonance. That can make for a bad picture.

I have an RCA CT-100 color TV with lots of peaking coils that are potted in something white that corrodes them. In fact though some of mine were bad, none were
so bad I was unable to unwind a few turns and get measurements of inductance and resonance. I had to experiment to get the waveforms to look right. I bought
two or three coils for each replacement. The best inductance value varied
up to 35% from spec. Most were noncritical but a couple were critical.

Putting coils in series thus generally simply won't better than just getting close.

on the "to do " list next time the chassis is out.

Replace R70 (out of tol) , & C31,R71 just to be sure, they are most likely OK , but new parts won't hurt, hopefully this can cure the retrace problem.

Inspect delay line VERY closely, checking for any damage at the grounding point, and see if repair/ replace needed, re-connect ground to OEM position, similar to as seen in GE chassis. Replace L13 that had been slightly damaged with NOS RCA part. Replace R64 with new 2% part, it's most likely OK, but while I have it out, why not, inspect L15/L15, they are on the topside of the PCB, and unlikely to be bad.

Check remaining original orange drop caps for leakiness.
Replace focus resistor & cap.
Fix the damn loose connection on the heater pin on the socket of the HOT. :(

I did manage to view the entire DVD , Watchmen Director's Cut, this weekend with it, and I saw no macrovision problems whatsoever, I'm not sure if it was because of the player used, or the DVD, or because I was using direct A/V input, but it was very stable, no problems at all.

Damn, L13 will be arriving surprisingly fast, It was shipped from within Texas, only 10 hours from here, It will be here Thursday.

The focus resistor, however, is coming from REEDLEY, CA, that will take a wile :(

does the 130 PF cap in the focus circuit really wear out that much and need replacing?

new L13 has arrived, no other parts yet, it does not look like the old one, but that is not unexpected,

https://i.imgur.com/pVTY6tn.jpg

found an old pic of the underside with the delay line and coil
https://i.imgur.com/1XZjvKL.jpg
you can see how I grounded it, and L13. (but not the damage to it )

waiting for the other parts

Well, USPS, “says” that the 66meg focus resistor is in the mailbox, but I won't fall for that again after the thermistor fiasco, I won't believe it until it's in my hands.

FEDEX says that the replacement for the 130pf cap in the focus circuit will come Friday, now there seems to be some flexibility on the value of a usable replacement, CTC 10-16 SAMs list no sub for it other than the RCA part# @130pf, but in the CTC 20, a 120pf is listed as a replacement, however, in the GE CTC 15 & 1/5 clone, it lists a 150pf as one, which I have used successfully, and since the focus circuits are all identical for the most part in all of them, I got another 150pf / 15kv for CTC-16XL.


Meaning that now, I should have have all the parts needed to do all the minor updated to my RCA that I had been wanting to do, including removing that black wire I have grounding the delay line, and grounding to the nearest gnd point via a heavy lead from a power resistor, the thicker, the better.

But, I'm still debating on to try it this weekend or to try and get the GE clone downstairs, setup and converged.
It's still too heavy for me to move on my own, so I'd have to bribe someone to help, or take it apart, IE remove the CRT from the cabinet and take them down separately, ( which I really don't want to do ).

The specs say a 21FJP22 is 43lbs, the cabinet rough guess is 20lbs? Separately, easy enough for one person to move, even with a shoulder that's healing fro surgery, together,, NOT... the chassis is very light compared to the CTC-16XL, and even the FADA rca 630ts clone, I was surprised at how light it was, like someone pointed out, GE= Good Enough.

Still not sure which way I'll go this weekend. :(

with them side by side now, i can really see the difference between the 21fjp22 and the 21fjp22A.

In the greens mostly. but I;m not sure if that is just a difference in the color/ video circuits of the CTC-15/GE and the 16XL.

About the focus circuit, I have seen it said that the 66meg (6kv) resistor gets hammered a lot and often drifts out of spec, I saw this in the GE-CTC-15 clone, but what about the 130pf ceramic cap? Are they pretty stable, or need attention also sometimes?

I've read a case or 2 of that ceramic cap going open-ish (not producing a good null on the eye tube of a restored 60's cap tester). But on average they are pretty reliable.

Then I don't think its bad in my 16xl, but I'm sure the resistor is worn, not that I CAN'T bring it into focus, but in order to do so, I'm almost at the limit of travel on the focus coil, so it can use a new one I'm sure.

Just another thing to add to the list next time I take it apart.

So far, my CTC-16XL has been going very well with hourly weekend usage, no major problems seen yet, other then the minor annoyances mentioned before.

So, until something pops up to urge me to pull it apart, I wont sweat the small stuff, but I may touch up convergence, it's a bit off again.
As stated before, on the list of minor stuff.

Replace the 66m focus resistor that seems to have drifted a bit.

Restore the grounding of the delay line to factory spec & put in new peaking coil to replace damaged one, ( though it may be OK, never hurts )

Replace resistors and cap on plate of video output, that gives vertical blanking. ( missed them when I restored it. )

That's about it.
:)