still finding some crappy resistors.
R52 (820k 5%) checked @ 930k and R55 (3.3k 10%) checked @ 4.6k.
not sure if that is the cause of the video smear yet, but will keep looking as I try to adjust 1st IF again.

I did find that changing from chan 3 to 4 on the RF mod i was using did help things :O

https://www.youtube.com/watch?v=FANpDmBCsEw&feature=youtu.be

still not sure about the smear yet :(

That looks a lot better. So definetly you were/are picking up some external interference. If you haven't already, try turning off all lights, computers, and any wall wart power supplies in the house. Almost all newer florescent and led fixtures and most power supplies emit wide band rf noise. Whenever I'm working with a TV or radio in my basement I have all things turned off except my old school magnetic ballast florescent lights above my workbench.

I don't think any resistors would be causing picture smear, that's most likely a tuning, noise, or alignment issue. Have you tested all of the video peaking coils for continuity?

Watching that video a second time, it almost looks like there are dark trails behind light objects, which could be from too high of brightness and/or contrast for the tired old CRT. Try taming that picture down and see if that helps. Or maybe it's just the camera making it look that way to me. Without seeing it up close it's kind of hard to distinguish what it really looks like. Possibly some other programming could create a more distinct picture? Overall that channel change made a real big improvement.

[edit] Just realize that's your test crt we're still watching. That in itself could be responsible for some of that tailing.

EICO came today as expected,
https://imgur.com/kaKymuU

and after a brief upgrade

replaced the paper caps ( that mattered , they were WAY off, ) the electrolytics , and replaced the selenium rectifier.


also cleaned all pots and switches.
https://imgur.com/UXStu5t

it's now VERY stable! :)

https://imgur.com/a/Y7sBu6J

all set to try again!

I viewed the YouTube video and you either have an IF alignment problem or a problem in the video amplifier (open peaking coil). The black streaking suggests the phase response is very bad.

Stagger tuned stages are optimised for both correct phase and frequency response. It is essential that the manufacturers alignment instruction be followed to the letter.

But I must ask, do you understand the concept of the split sound design and vestigial sideband demodulation? Because unless you do, you will continue to go around in circles.

I viewed the YouTube video and you either have an IF alignment problem or a problem in the video amplifier (open peaking coil). The black streaking suggests the phase response is very bad.

Stagger tuned stages are optimised for both correct phase and frequency response. It is essential that the manufacturers alignment instruction be followed to the letter.

But I must ask, do you understand the concept of the split sound design and vestigial sideband demodulation? Because unless you do, you will continue to go around in circles.


There are 6 peaking coils after the video det, all check good resistance wise.

as was mentioned earlier the 1st IF coil L9 was broken and is new, and thus the hunt for a stable freq generator
have not had a chance to try to adjust it again.

Also, as someone said who has worked on these things, "the 4 720 pf coupling capacitors in the picture IF section can be troublesome."

if adjusting L9 does not help much, they are next

There are 6 peaking coils after the video det, all check good resistance wise.

as was mentioned earlier the 1st IF coil L9 was broken and is new, and thus the hunt for a stable freq generator
have not had a chance to try to adjust it again.

Also, as someone said who has worked on these things, "the 4 720 pf coupling capacitors in the picture IF section can be troublesome."

if adjusting L9 does not help much, they are next

Those micas are known to be an issue in RCA sets and usually result in a totally dead or hopelessly oscillating IF. I suspect they are not the problem your looking for, but if you are aligning the IF anyway there's no harm in changing them.

as was mentioned earlier the 1st IF coil L9 was broken and is new, and thus the hunt for a stable freq generator
have not had a chance to try to adjust it again.


Was that 43pf cap shown in parallel with the trap side of that 1st IF external to the old transformer? There is no dotted line shown around it on the Sams schematic, so I assume it was located outside the IF can. If by chance it was internal to the replacement you would now have twice the rated capacity. But you probably would have caught that.

There are 6 peaking coils after the video det, all check good resistance wise.



Let me bore you with a story regarding peaking coils:

Back when I was just starting out in the family business, I had a Sylvania D series (hybrid) that had a color problem. I knew enough at that point to know the 3.58 osc wasn't running, but couldn't figure out why.

Dad put my older brother on it and within about 10 minutes he showed me a peaking coil and said to change it. I smirked and told him it wasn't the problem because the resistance was the same as the others just like it in the circuit. He explained that it probably had a shorted turn which would have little to no effect on the resistance, but a shorted turn would essentially turn it from a coil to a resistor.

Well, he was right. That was my first experience in magnetics. That was a good lesson, one I never forgot.

Probably not the problem here, but just to point out that normal resistance on coils only proves there's no broken wire inside.

John

Was that 43pf cap shown in parallel with the trap side of that 1st IF external to the old transformer? There is no dotted line shown around it on the Sams schematic, so I assume it was located outside the IF can. If by chance it was internal to the replacement you would now have twice the rated capacity. But you probably would have caught that.

there was no can per-sey
it was all wax-paper
https://i.imgur.com/hRDLbIF.jpg
with the trap coil over the internal coil.

the new one is slightly different
both are in a metal can, with both coils on one central paper core, the trap wound above the RF one, both tuned the same way, and the trap coil did have a cap in parallel on it.

sort of like this
https://www.pirate-pete-electronics.com/photos/E_COMP_coil_var_dual-01_01.jpg
top coil having the cap

Let me bore you with a story regarding peaking coils:

Back when I was just starting out in the family business, I had a Sylvania D series (hybrid) that had a color problem. I knew enough at that point to know the 3.58 osc wasn't running, but couldn't figure out why.

Dad put my older brother on it and within about 10 minutes he showed me a peaking coil and said to change it. I smirked and told him it wasn't the problem because the resistance was the same as the others just like it in the circuit. He explained that it probably had a shorted turn which would have little to no effect on the resistance, but a shorted turn would essentially turn it from a coil to a resistor.

Well, he was right. That was my first experience in magnetics. That was a good lesson, one I never forgot.

Probably not the problem here, but just to point out that normal resistance on coils only proves there's no broken wire inside.

John

well those coils a pretty much unobtainium,
you would be lucky to find 1, let alone all 6.

and the resistance does seem to check out with what is shown on the 630ts service guide. :O

and the resistance does seem to check out with what is shown on the 630ts service guide. :O

Yes, but if one turn shorts out to an adjacent turn, it will have no measurable effect on the resistance you read with a meter. But what happens with a shorted turn is that one single shorted turn kills the Q of the coil. At that point, an 8 ohm peaking coil becomes an 8 ohm resistor.

Again, unlikely that's your problem, but I was just pointing out that a single shorted turn can't be read with an ohmmeter.

That's why ringers were so popular with TV techs. A shorted turn in a flyback, yoke, vertical output transformer, etc. won't show up in a resistance check, but will in a ringing test.

I bought an LC75 Sencore Z Meter brand new back in 1985 and still use the crap out of it. It will perform both ringing tests and test the value of any inductor as well. Smaller inductors that don't ring well on ringers can be tested for their value.

I paid $1000 for the Z-Meter back in '85, but today, we can buy these handy multi-testers for pocket change:

https://i.ebayimg.com/images/g/aakAAOSwiwZb6k4S/s-l500.jpg

I know these are toys, but I couldn't resist and bought one. Just put any two or three lead part into the socket in any direction, and this toy will identify what it is, what the lead configuration is, and give you things like transistor gain, resistance in ohms, capacitance and ESR, and inductor values. These will check inductors for value but no ring test. But a shorted turn in an inductor will throw off the value. If your TV has more than one of the same part, you can compare them if the schematic doesn't identify the value of the inductor.


John

Yes, but if one turn shorts out to an adjacent turn, it will have no measurable effect on the resistance you read with a meter. But what happens with a shorted turn is that one single shorted turn kills the Q of the coil. At that point, an 8 ohm peaking coil becomes an 8 ohm resistor.

Again, unlikely that's your problem, but I was just pointing out that a single shorted turn can't be read with an ohmmeter.

That's why ringers were so popular with TV techs. A shorted turn in a flyback, yoke, vertical output transformer, etc. won't show up in a resistance check, but will in a ringing test.

I bought an LC75 Sencore Z Meter brand new back in 1985 and still use the crap out of it. It will perform both ringing tests and test the value of any inductor as well. Smaller inductors that don't ring well on ringers can be tested for their value.

I paid $1000 for the Z-Meter back in '85, but today, we can buy these handy multi-testers for pocket change:

https://i.ebayimg.com/images/g/aakAAOSwiwZb6k4S/s-l500.jpg

I know these are toys, but I couldn't resist and bought one. Just put any two or three lead part into the socket in any direction, and this toy will identify what it is, what the lead configuration is, and give you things like transistor gain, resistance in ohms, capacitance and ESR, and inductor values. These will check inductors for value but no ring test. But a shorted turn in an inductor will throw off the value. If your TV has more than one of the same part, you can compare them if the schematic doesn't identify the value of the inductor.


John

$1000 in 1986 money? :yikes:
but that is the problem, something to really test them are VERY costly.

$1000 in 1986 money? :yikes:
but that is the problem, something to really test them are VERY costly.

In terms of the time it saved me in the past 35 years, it not only cost nothing but made me a small fortune. It's been in continuous use since I bought it.

But the cheap tester I linked is like $15, and will read inductors like your peaking coils for values between .01mh and 20h. It's likely not as accurate as the Z-Meter but it doesn't have to be either.

Next week I'll run some small inductors through the cheap tester and compare them to the Z-Meter and see how accurate it is. I did compare it to the Z-Meter for value and ESR on capacitors, and it was close.

John

OK, I attempted again to tune the 1st IF coil and this is what I found.

Following the instructions, and adjusting the “ contrast control point stated to -3v as mentioned caused NO readable voltage at point A, no matter what I did , no deflection was seen, and when a video was fed in, it was cut off completely.

Turning contrast back up to the point the picture came back, the voltage was about -1.4
Point A would then react to the RF input and I adjusted the coil.

This did not seem to help the picture much as after I was done, there seemed to be more RF noise than when I started.

So obviously there are other things wrong with the IF, most likely more bad resistors, and perhaps the bypass caps, setting it to -3v like it says in setup should not cause nothing to pass though.


Also, the black streaking seen on bright objects on the screen is NOT from the IF, as I bypassed it and fed direct video in and it was still there, but as Kevin Kuehn mentioned, it could be caused by the old test CRT and not the video circuits.

but now I must go over the IF section and look for more bad resistors, it's that ot just go direct video input :/

definitely more bad resistors :sigh:

example, the 39 ohm cathode resistor R24 for 1st IF checked at 53 ohms, and the one for 2nd is 48 ohms.
no wonder the gain is all messed up

definitely more bad resistors :sigh:

example, the 39 ohm cathode resistor R24 for 1st IF checked at 53 ohms, and the one for 2nd is 48 ohms.
no wonder the gain is all messed up


In the 20% to 30% area. Don't be surprised if that has little to no effect.

John

I just went over the IF checking resistors , and 50% of them are over the %20 tolerance rating, by quite a lot, not sure if i should replace the coupling caps now yet or not... :/

In the 20% to 30% area. Don't be surprised if that has little to no effect.

John
and I would think that the effect would be additive, if half of the resistors are %20-%40 or more out of spec, it has to have an effect on how well it works.

for example,
https://imgur.com/gBixele
i find it quite hard to believe that a resistor this far out of tolerance would not cause many problems.
and as I mentioned, almost half of them are this bad.


edit

another example..
https://imgur.com/XZsIK7W

that SHOULD BE 39 :O

Changing the resistors did make a marginal improvement, but there is still a snowy picture.
I am guessing the RF amp is still weak. When checking voltage there it was still too low.
Should have 130v and was 107v
I then looked at the main 130v line, it TOO was low.
109v
that comes via the bleeder resistor (1.36k) from the 275v which is ay about 265v once things warm up.( close enough.
That bleeder is still getting quite warm :/
IT checks OK resistance wise, but that does not mean anything :/
gonna have to replace it.

It calls for a 17w part :o
closest I could find was 1.3 kOhms at 25 w

Hopefully this will get the voltage in the right area
anyway, here is how it looks with direct video input
https://www.youtube.com/watch?v=YIMiHQ_02fc&feature=youtu.be

That's not coming from the picture tube, so cross that off your list.

But it could be a bad peaking coil.

John

That's not coming from the picture tube, so cross that off your list.

But it could be a bad peaking coil.

John

i have no way to test them, yet...
I do have one of those ultra cheap LCR meters coming from , china that should be able to test them, out of circuit, but if any are bad, they will be very hard to find any replacements.
this tester
https://www.ebay.com/itm/283562838501


keep in mind that right now my 130v bias id about 25v or more low, i don't know what that effect that has on everything, but once the resistor is changed, i will see what happens.

“I do have one of those ultra cheap LCR meters coming from , china that should be able to test them, out of circuit, but if any are bad, they will be very hard to find any replacements.”

Mouser and others stock tons of small iinductors, are these not suitable?

https://www.mouser.com/Passive-Components/Inductors-Chokes-Coils/Fixed-Inductors/_/N-wpcz

jr

“I do have one of those ultra cheap LCR meters coming from , china that should be able to test them, out of circuit, but if any are bad, they will be very hard to find any replacements.”

Mouser and others stock tons of small iinductors, are these not suitable?

https://www.mouser.com/Passive-Components/Inductors-Chokes-Coils/Fixed-Inductors/_/N-wpcz

jr


i'm not sure if they work the same in this situation or not, no idea if they do the same thing as a " peaking coil " in a video amp circuit.

i'm not sure if they work the same in this situation or not, no idea if they do the same thing as a " peaking coil " in a video amp circuit.

Search this site for posts by miniman82 on replacement peaking coils for CT100 or 21CT55 the family the recommended inductors are in contains a good variety of leeded inductors of various values. After replacing the peaking coils in my 21CT55 if I need coils for any other set I usually check that family for something with the correct inductance.

https://imgur.com/UnvD4ps

I'm gonna replace both of those resistors, i guess the 6.75k is checking a 5.43, that's prob dragging down the 130v :/

Changing the resistors did make a marginal improvement, but there is still a snowy picture.
I am guessing the RF amp is still weak. When checking voltage there it was still too low.
Should have 130v and was 107v
I then looked at the main 130v line, it TOO was low.
109v
that comes via the bleeder resistor (1.36k) from the 275v which is ay about 265v once things warm up.( close enough.
That bleeder is still getting quite warm :/
IT checks OK resistance wise, but that does not mean anything :/
gonna have to replace it.

It calls for a 17w part :o
closest I could find was 1.3 kOhms at 25 w

Hopefully this will get the voltage in the right area
anyway, here is how it looks with direct video input
https://www.youtube.com/watch?v=YIMiHQ_02fc&feature=youtu.be

In an attempt to narrow things down you could try pulling rf and if tubes one at a time to see if your 135v supply increases significantly with any of them removed. When something is drawing too much current and pulling the supply down, you're not going to fix anything by changing resistors that are high or normal in value.

Another thought is the tuner and IF sections have a whole slug of 1500pf power supply bypass caps between B+ to ground. If pulling those RF and IF tubes doesn't give results, it's possible you have one or more bypass caps that are leaky. Also if you disconnect one end of R39(Sams 150 ohm) you would free up that 135v supply from the 4th IF stage forward. Something needs to give and it's simply a matter of sniffing it out. The key here is you need to divide and concur to find out what circuit is pulling the voltage down. Forget worrying about your picture quality until you find what is pulling that B+ down.

Another thought is the tuner and IF sections have a whole slug of 1500pf power supply bypass caps between B+ to ground. If pulling those RF and IF tubes doesn't give results, it's possible you have one or more bypass caps that are leaky. Also if you disconnect one end of R39(Sams 150 ohm) you would free up that 135v supply from the 4th IF stage forward. Something needs to give and it's simply a matter of sniffing it out. The key here is you need to divide and concur to find out what circuit is pulling the voltage down. Forget worrying about your picture quality until you find what is pulling that B+ down.

well. the 6.75k resistor is definitely testing too low, by almost 1 k out of circuit, it's a 3 resistor thingy stuck in 1 pack, the other 2 check fine 12 & 93 ohms.
i got new ones coming Tue, and will replace the 6.75k first and see what happens.

well. the 6.75k resistor is definitely testing too low, by almost 1 k out of circuit, it's a 3 resistor thingy stuck in 1 pack, the other 2 check fine 12 & 93 ohms.
i got new ones coming Tue, and will replace the 6.75k first and see what happens.

Changing that one first is fine.

It's easier for me to follow these power supply voltages using the Riders schematic I posted here. https://www.flickr.com/photos/152661900@N02/49527015703/in/album-72157713086856613/

[edit] So if your 6.75k is part of a candohm, it's possible that part of it's winding is shorting to ground by insulation breakdown. If that's the case you'll be much further ahead by replacing all three sections. Otherwise it would be unusual for a resistor to drift down in value.

Another thought is the tuner and IF sections have a whole slug of 1500pf power supply bypass caps between B+ to ground. If pulling those RF and IF tubes doesn't give results, it's possible you have one or more bypass caps that are leaky. Also if you disconnect one end of R39(Sams 150 ohm) you would free up that 135v supply from the 4th IF stage forward. Something needs to give and it's simply a matter of sniffing it out. The key here is you need to divide and concur to find out what circuit is pulling the voltage down. Forget worrying about your picture quality until you find what is pulling that B+ down.


there are 21 of those little bastards in there. :(
all still orig, I was hoping they would not be a problem, but if the new 6.750 k bleeder does not bring up the 135v to around where it should be, they are next on the list, might as well get them all, they are cheap enough.
I just hope that the resistors IN the tuner are OK, for I really don't want to go in there or have to take it out to get to them, but with the way that I have found some resistors that were almost 2x over what they should be, I DO wonder...
But finding resistors that far off does not surprise me, given that this thing spent 2/3s of it's life neglected in a dark, dank musty basement in Pennsylvania.
And I know that carbon resistors HATE THAT! :tears::nono:

Yes, but if one turn shorts out to an adjacent turn, it will have no measurable effect on the resistance you read with a meter. But what happens with a shorted turn is that one single shorted turn kills the Q of the coil. At that point, an 8 ohm peaking coil becomes an 8 ohm resistor.

Again, unlikely that's your problem, but I was just pointing out that a single shorted turn can't be read with an ohmmeter.

That's why ringers were so popular with TV techs. A shorted turn in a flyback, yoke, vertical output transformer, etc. won't show up in a resistance check, but will in a ringing test.

I bought an LC75 Sencore Z Meter brand new back in 1985 and still use the crap out of it. It will perform both ringing tests and test the value of any inductor as well. Smaller inductors that don't ring well on ringers can be tested for their value.

I paid $1000 for the Z-Meter back in '85, but today, we can buy these handy multi-testers for pocket change:

https://i.ebayimg.com/images/g/aakAAOSwiwZb6k4S/s-l500.jpg

I know these are toys, but I couldn't resist and bought one. Just put any two or three lead part into the socket in any direction, and this toy will identify what it is, what the lead configuration is, and give you things like transistor gain, resistance in ohms, capacitance and ESR, and inductor values. These will check inductors for value but no ring test. But a shorted turn in an inductor will throw off the value. If your TV has more than one of the same part, you can compare them if the schematic doesn't identify the value of the inductor.


John


Update: I took an NOS RCA peaking coil from my parts supply and measured it. On my Z-Meter, it reads 5.8uh (marked 5.6 on the bag).

On my cheapo mega328 tester, it reads as a 0.2 ohm resistor... I tried several times and did the calibration procedure, but it won't read inductors - it sees them as resistors. Now, this tester is at least three years old and it's possible that this early version didn't read inductors while the later ones (which still look identical) purportedly do.

Incidentally, on the Sencore Z-Meter this 5.6uh peaking coil shows 5 rings.

Lastly, this is an RCA part number 119590. Judging by the part number, I'd say this is an early 60s to mid 60s coil for a color TV, but it likely covered many years.

If anyone wants this, it's theirs for the asking. Email me at [email protected]

John

Well the thing I got ( when ever it gets here ) was only about $6.50, and they say it does coils, and 5.6uh is kinda small :o
the ones in the set are 93-120-250 , just have to see what happens when ever it gets here, on the slow boat from China...

Update: I took an NOS RCA peaking coil from my parts supply and measured it. On my Z-Meter, it reads 5.8uh (marked 5.6 on the bag).

On my cheapo mega328 tester, it reads as a 0.2 ohm resistor... I tried several times and did the calibration procedure, but it won't read inductors - it sees them as resistors. Now, this tester is at least three years old and it's possible that this early version didn't read inductors while the later ones (which still look identical) purportedly do.

Incidentally, on the Sencore Z-Meter this 5.6uh peaking coil shows 5 rings.

Lastly, this is an RCA part number 119590. Judging by the part number, I'd say this is an early 60s to mid 60s coil for a color TV, but it likely covered many years.

If anyone wants this, it's theirs for the asking. Email me at [email protected]

John
My 328 based tester (which died on me a while ago) couldn't read inductance that low. Also the lower the inductance the higher the series resistance of the coil had to be to be for it to NOT register as a resistor. It is a quirk to be aware of. These meters are useful (why I'm going to replace mine again) but not as good as a pricey dedicated inductance tester, didicaed cap/ESR tester or dedicated Solid state devices tester...it's only good within it's range limits.

Well the thing I got ( when ever it gets here ) was only about $6.50, and they say it does coils, and 5.6uh is kinda small

Yep. Just checked, it will read as low as 10uh. The one I tried was 5.6uh. I'll pick a higher value tomorrow and see how it compares. I did try some capacitors today while I was playing with it, and it's pretty accurate with capacitors, and the ESR values were very close to what the Sencore Z-Meter says they are. The only thing it can't do is leakage.


... on the slow boat from China...

The longer it takes to get here, the better...

:D

John

there are 21 of those little bastards in there. :(
all still orig, I was hoping they would not be a problem, but if the new 6.750 k bleeder does not bring up the 135v to around where it should be, they are next on the list, might as well get them all, they are cheap enough.
I just hope that the resistors IN the tuner are OK, for I really don't want to go in there or have to take it out to get to them, but with the way that I have found some resistors that were almost 2x over what they should be, I DO wonder...
But finding resistors that far off does not surprise me, given that this thing spent 2/3s of it's life neglected in a dark, dank musty basement in Pennsylvania.
And I know that carbon resistors HATE THAT! :tears::nono:

How difficult is it to lift that 3 section candohm from the chassis, assuming it's riveted on. Doing so you may see your low resistance section move back closer to 6.750k. If that holds true, then leaving it isolated from the chassis it's likely you'd also see your 107V B+ come closer to 135v, as well as your 265V increase to 275V. It's something you could do while waiting for the replacement resistor to arrive. Keeping in mind the Candohm will heat up much more so than normal when it's physically not being heatsinked to the chassis, so this is only a short test to see if the B+ increases.

The above scenario is all based on my hunch that the one section has burned through the fish paper and is partially shorted to ground. And also requires that there's not a wire physically connecting the Candohm housing to ground.

I will have the new resistor today, and be able to try it tonight and see how things work.
I will most likely replace the 1500pf caps this weekend as well, but I'm not sure if I should touch those silly 270pf domino mica capacitors yet or not. :/

yop. those damn 1500pf caps are no good.

put in the new resistor the 109V came up to 112V. :( not much better.

unhooked R39 (R130 on riders/RCA) the one feeding the voltage to the IF, and it came up to 139v.

they all gotta go.

yop. those damn 1500pf caps are no good.

put in the new resistor the 109V came up to 112V. :( not much better.

unhooked R39 (R130 on riders/RCA) the one feeding the voltage to the IF, and it came up to 139v.

they all gotta go.

Similarly you could remove R26 feeding B+ to the tuner, reinstall R39 and get an indication of whether it's mostly in the tuner or IF section. Of course there's the possibility that more than one caps are leaking. You can even go so far as to put a dc ma meter in series with R39 and you'll see the accumulative draw from each progressing stage. What would be very interesting is to see current draw with and without the RF and IF tubes installed. If it's the caps you'd still be seeing significant current being drawing without the tubes in. Time consuming work but very rewarding if you can narrow down the point of failure.

Similarly you could remove R26 feeding B+ to the tuner, reinstall R39 and get an indication of whether it's mostly in the tuner or IF section. Of course there's the possibility that more than one caps are leaking. You can even go so far as to put a dc ma meter in series with R39 and you'll see the accumulative draw from each progressing stage. What would be very interesting is to see current draw with and without the RF and IF tubes installed. If it's the caps you'd still be seeing significant current being drawing without the tubes in. Time consuming work but very rewarding if you can narrow down the point of failure.

well I just ordered 21 of these, https://www.mouser.com/ProductDetail/667-ECQ-E6152KF
they SAY the the ones in there are ceramic, but I am not sure what the hell they are, I tend to think they are more like the elmenco tubular ceramic shell caps bombs that were in my CTC-16LX, they went bad as well, i took one apart and it had wax seals on the ends, and to quote Electronic M, 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 just should have replaced them all at first :/

well I just ordered 21 of these, https://www.mouser.com/ProductDetail/667-ECQ-E6152KF
they SAY the the ones in there are ceramic, but I am not sure what the hell they are, I tend to think they are more like the elmenco tubular ceramic shell caps bombs that were in my CTC-16LX, they went bad as well, i took one apart and it had wax seals on the ends, and to quote Electronic M, 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 just should have replaced them all at first :/

My only reservation on the wholesale replacement of those is it may complicate your alignment requirements, but you wanted to learn full blown alignment anyway. ;)

[edit] Just looked at what you ordered. Ceramic NPO may have been a better choice, but oh well.

My only reservation on the wholesale replacement of those is it may complicate your alignment requirements, but you wanted to learn full blown alignment anyway. ;)

[edit] Just looked at what you ordered. Ceramic NPO may have been a better choice, but oh well.

they are unlikely to change much of anything, as they seem to be mostly noise filters on the power and ground planes, unlike the coupling caps (720 pf ) which i have, but am hesitant to put in right now, for that reason.

they are unlikely to change much of anything, as they seem to be mostly noise filters on the power and ground planes, unlike the coupling caps (720 pf ) which i have, but am hesitant to put in right now, for that reason.

I tend to agree. Although I've heard others advise that they can have subtle effects on alignment.

My only reservation on the wholesale replacement of those is it may complicate your alignment requirements, but you wanted to learn full blown alignment anyway. ;)

[edit] Just looked at what you ordered. Ceramic NPO may have been a better choice, but oh well.

https://imgur.com/lswPluo

as mentioned,, the same sort of thing happened on my 16-XL and i replaced the .001 with Panasonic films also.

worked OK,

I'm really not that worried about these new caps, the replacement specs were 20% @ 350v, and these new film ones are 10% @ 630v.
And like I mentioned, not in a critical area where they have mica caps used.

I just hunted up every vintage Miller / Merit peaking coil I could on Ebay and grabbed what I could.
Still 1 short :(
Found, NIB, 2 120 mh, 1 93 mh, 1 250 mh, and 1 180 mh...
short 1 93 mh. :/
Now I don't know that the ones in the set are necessarily bad, but as it's been pointed out more than once, I don't know that they are good, so now I have at least 5 out of 6 NIB ones to try.

have started to replace the little buggers...
https://imgur.com/1As2s9h

https://imgur.com/evHg7rm

this is gonna take a while :o
it does look like some of them have leaked some wax :(

I got my fingers in on of those :p
you can see I marked all the resistors that tested OK with a green mark.

So, from what I understand, the cheapo mega328 tester should be able to test the coils in my tv, 93uh – 250uh, cause as mentioned, I only found 1 of the 2 new 93s needed, so I will have to re-use whichever one that's in there that tests best, and from what I read, the new ones need to be put in exactly the same way as the old ones... just how critical is that?
If coil #xx1 was ##mm on the left side with the leads, and ##mm on the right, sitting ##mm above the metal chassis, does the replacement have to be exact, or is there some wiggle room?

So, from what I understand, the cheapo mega328 tester should be able to test the coils in my tv, 93uh – 250uh, cause as mentioned, I only found 1 of the 2 new 93s needed, so I will have to re-use whichever one that's in there that tests best, and from what I read, the new ones need to be put in exactly the same way as the old ones... just how critical is that?
If coil #xx1 was ##mm on the left side with the leads, and ##mm on the right, sitting ##mm above the metal chassis, does the replacement have to be exact, or is there some wiggle room?

I was screwing around with my 328, and it's pretty accurate with capacitors, ESR, and even inductors over 10uh are close enough. What it's not accurate at is resistance under one ohm. A 0.47 read 0.33. On my Fluke, it read 0.46.

Any component in the IF should be replaced as close to its original physical location as is possible. Even moving a part aside to resolder a tube socket has some (possibly insignificant) effect on alignment. In any case, you don't want to leave long leads.

John

I was screwing around with my 328, and it's pretty accurate with capacitors, ESR, and even inductors over 10uh are close enough. What it's not accurate at is resistance under one ohm. A 0.47 read 0.33. On my Fluke, it read 0.46.

Any component in the IF should be replaced as close to its original physical location as is possible. Even moving a part aside to resolder a tube socket has some (possibly insignificant) effect on alignment. In any case, you don't want to leave long leads.

John

the coils in question ARE in the video amp section, so that's why I'm wondering.
https://imgur.com/vXqVDJB
I ca see how in the IF area it really does, but does it in the video amp as well?

An IF (or RF) is a high-Q circuit, the coils in video amps are in
low-Q situations. They are less critical, but try to get them right, especially
distance from the chassis.

That's odd, there are 2 types of 1500 PF caps in there, even though it's not mentioned on the docs.

the white ones sealed with wax that look like paper ones, and brown ones ( open ended, both are tube shaped )
:o
there are these https://imgur.com/FDVtxmP

and these
https://imgur.com/ObBmxmO

am I reading those little brown tube caps right? brown green red green, 1500 pf 5%? :o

EDIT

I guess i will have to change my approach :(

i have these, https://imgur.com/vY5TIS7
Which I'm still not sure what type they are, but they match the part list, 1500pf 350v 20%, the wax ends are very suspect, they may be leaking wax. Been replacing with film type 650v 10%

then saw this in there.
https://imgur.com/Gdv9iop
5% from what I can tell, so it would be unwise to put 10% in there...
gonna look for some highly stable 3% kinds.

Those are ceramic caps and rarely go bad. Don't worry about the tolerance. They are simply bypass caps.

all the waxy white 1500 caps replaced.

tried again
https://www.youtube.com/watch?v=Id3OWPlHtVo
behaving a bit better now

still snow in pic, I got it this way bu visual adjust of 1st IF coil this time rather than trying to follow setup instructions.
not sure if the other coils are right or not, or if there may be problems in the tuner as well , out of spec resistors , there are a few of the same 150 ohm ones that were VERY bad in the IF strip, some almost 2x too high, but getting that thing out of there to get to them is a pain it the ass, and I dread attempting to try.
I wont have all the new peaking coils for about a week, as 3 of them are coming from Canada. :(

If i do try the IF alignment as per the procedure again, I will most likely try with a digital RF generator with amplitude control, but that may take a while to get one :/

Contrast control mod for FADA (rca 630ts clone)...

https://imgur.com/0pAv0eh

this circuit was literally copied from the CTC-16/XL.
The same appears in many other RCA color sets with only slight variations.
The FADA has a 330 ohm resistor to gnd on the video output now, I see no reason why putting this in won't work as it does in the color sets, (just have to find s 330 ohm pot ), giving it a REAL contrast cont, and not what it has now, an adjustment for RF/IF gain that has an affect on both picture and sound.

So after changing all those bypass caps is your B+ back where it should be in the tuner and video IF circuits?

I can't remember if you showed us your tuner? I'm wondering if it's the standard coil type, and if so have you tried adjusting the local oscillator adjustment for the individual channel you're set to? If it has those adjustments they can be off enough that the fine tuning won't get you best picture and sound.

That contrast mod should work. Likely you can even use a 500 ohm pot. However you'll still need to set the rf/if gain for best operation as there is no AGC in this set. But you'll at least have separate gain control over video.

So after changing all those bypass caps is your B+ back where it should be in the tuner and video IF circuits?

I can't remember if you showed us your tuner? I'm wondering if it's the standard coil type, and if so have you tried adjusting the local oscillator adjustment for the individual channel you're set to? If it has those adjustments they can be off enough that the fine tuning won't get you best picture and sound.

That contrast mod should work. Likely you can even use a 500 ohm pot. However you'll still need to set the rf/if gain for best operation as there is no AGC in this set. But you'll at least have separate gain control over video.

It seems to be the standard tuner as it appears in the sams, I have not tried to adjust anything else other than the 1st IF at this point.

The voltages are up a bit more to where they should be, it seems that the voltages shown on the riders (& rca 630ts service manual docs ) are misleading, after looking at it for some time, it hit me, how can the voltage on the plate of the 1st IF tube be @ 135v, if the source bias is 135v, going through 3 150 ohm resistors and 1 1k one? It can't be...
It must be wrong.
Sams shows it to be 95v :o
And sams shows the (135v) to be 117v.. :/

mine are now very close to that, so I guess the voltage was mostly OK to start with.
But still, when I tried to go “by the book” to adjust the 1st if, it did not work right.

1) remove osc tube, did that...
2) DC probe at junction of R40-R41, adjust “contrast” to -3 volts, leave it there.
This did not work, it cut off all input from tuner/if , no input defection at all, had to take it up to -1.2 to get it to do anything, and when I did try at that point, it ended up worse than when I started. :(

It was this point I replaced the WHITE waxy caps, and re-adjusted 1st IF visually, to get to where I am now.

1) remove osc tube, did that...
2) DC probe at junction of R40-R41, adjust “contrast” to -3 volts, leave it there.
This did not work, it cut off all input from tuner/if , no input defection at all, had to take it up to -1.2 to get it to do anything, and when I did try at that point, it ended up worse than when I started. Sure seems to indicate a lack of gain in the tuner, which coincides with snow in picture. I wonder what would happen if you inject your alignment signal to a tube shield hovering over the local oscillator tube, so it's not grounded. That should capacity couple the signal so it's fed to the first IF stage. If that doesn't work I'd try through a capacitor to the first IF grid. [edit] forgot to mention you need to snip I think pin 1 on a 6J6 to capacity couple through a shield over a 6j6, which I think is the plate. Basically disables the oscillator and couples to the 2nd rf tube.

Sure seems to indicate a lack of gain in the tuner, which coincides with snow in picture. I wonder what would happen if you inject your alignment signal to a tube shield hovering over the local oscillator tube, so it's not grounded. That should capacity couple the signal so it's fed to the first IF stage. If that doesn't work I'd try through a capacitor to the first IF grid. [edit] forgot to mention you need to snip I think pin 1 on a 6J6 to capacity couple through a shield over a 6j6, which I think is the plate. Basically disables the oscillator and couples to the 2nd rf tube.

I'm rather worried about the 2 150 ohm resistors in the tuner's rf amp section, they are the same kind that were in the IF section, (all bad), and if they are as bad as this one, it's no wonder there is poor gain.

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

there is a point E, that they suggest feeding in a signal into when alignment it REALLY bad, it's on the far end of the mixer coil stack in the tuner, and feeds into 1st IF.

I have found very few resistors bad above 1k ( just a few), but so far EVERY ONE, of the 150 ohms has been bad by 60%-190%, and there are 3 in the tuner :(
but I really dread pulling it out to replace them.

I'm rather worried about the 2 150 ohm resistors in the tuner's rf amp section, they are the same kind that were in the IF section, (all bad), and if they are as bad as this one, it's no wonder there is poor gain. See below.


there is a point E, that they suggest feeding in a signal into when alignment it REALLY bad, it's on the far end of the mixer coil stack in the tuner, and feeds into 1st IF. This sounds reasonable to try.



I have found very few resistors bad above 1k ( just a few), but so far EVERY ONE, of the 150 ohms has been bad by 60%-190%, and there are 3 in the tuner :(
but I really dread pulling it out to replace them.

You can measure B+ plate resistors in the tuner between tube socket plate pins to some other B+ point accessible outside the tuner. If there's more than one in series simply add up their values. Then you will know instead of wondering. Study the schematic and you may be able to sniff out others using the same method.

https://imgur.com/y84aCsd
OK..
I can't get a stable reading of any resistance between pin 1-2 , it's jumping all over the place, prob from going through all the coils, nor can i get a stable reading of resistance to the point "red wire" but there is 68v on both plates, ( sams says 50v)

between pins 5-6 was 438 ohms, ( additive of the 2 150 ohm resistors ), voltage at those pins changed dramatically with picture (contrast ) control.

https://imgur.com/y84aCsd
OK..
I can't get a stable reading of any resistance between pin 1-2 , it's jumping all over the place, prob from going through all the coils, nor can i get a stable reading of resistance to the point "red wire" but there is 68v on both plates, ( sams says 50v)

between pins 5-6 was 438 ohms, ( additive of the 2 150 ohm resistors ), voltage at those pins changed dramatically with picture (contrast ) control.

From either pin 1 or 2 of the rf amp to the red B+wire you should read around 3,500 ohms if R1, 2, 4, 11 were close to as marked. R1, R2 are paralleled by the tuner switch and those are in series with R4, R11. It's possible your meter is charging some cap, but I'm not seeing it at first glance. Or maybe the meters voltage is setting up an oscillation, who knows. All those tuning coils should read relatively low DC resistance compared to the higher total resistance. Anyhow it appears you now have a decent B+ getting to those plates, so I'm getting a little lost with the ups and downs.

From either pin 1 or 2 of the rf amp to the red B+wire you should read around 3,500 ohms if R1, 2, 4, 11 were close to as marked. R1, R2 are paralleled by the tuner switch and those are in series with R4, R11. It's possible your meter is charging some cap, but I'm not seeing it at first glance. Or maybe the meters voltage is setting up an oscillation, who knows. All those tuning coils should read relatively low DC resistance compared to the higher total resistance. Anyhow it appears you now have a decent B+ getting to those plates, so I'm getting a little lost with the ups and downs.

I'm not sure if its a tuner issue still or not, there is still snow in the pic, the 150 ohm resistors DO seem to be a bit off, but i don't know how much it is affecting anything in there.

I could try re-checking the plate resistance with a non digital meter, I think i have one, not sure.
the tubes in the tuner ARE new.

could this all be IF? or both, perhaps no way to tell really :/

Things I'm wondering about...

that mystery 680k pullup to 275v that was never hooked up, should it be tried now perhaps, because it does have an effect on the IF/tuner.

The 2 150 ohm resistors (measured from 5-6 on rf amp ) was collectively 438 ohms, which is quite a bit over 30%, (46%, from what I can tell.) I don't know which one is bad (most likely both ) and what the loss of possible balance is doing to the amp circuit, I can only speculate on how it really works right now.

I do have a mostly working analog multimeter, and will try to measure the plate resistance again on the RF amp.

Plan to do...
Remove the run of balanced 300 ohm wire running from the back of set to tuner and solder channel master cm-94444 balun directly into tuner, grounding 75 ohm to chassis via cap.

Replace peaking coils & video output tube (have 2 out of 5 ordered so far ) , hoping this will stop video smear.

Add contrast mod as mentioned before.

I have a new digital rf signal generator & LCR meter, no idea when they will get here, will re-try alignment when it comes, with exact freq set (I hope) and amplitude control.
Will also be able to test the old coils.

And after all that, I still can't get a clear pic w/o snow / RFI, perhaps convert to A/V input.

From either pin 1 or 2 of the rf amp to the red B+wire you should read around 3,500 ohms if R1, 2, 4, 11 were close to as marked. R1, R2 are paralleled by the tuner switch and those are in series with R4, R11. It's possible your meter is charging some cap, but I'm not seeing it at first glance. Or maybe the meters voltage is setting up an oscillation, who knows. All those tuning coils should read relatively low DC resistance compared to the higher total resistance. Anyhow it appears you now have a decent B+ getting to those plates, so I'm getting a little lost with the ups and downs.


found 2 meters that worked well, my 16 year old fluke 77, says it's 4.39k so did the very old Micronta 22-220, but the no-name brands gave me crap, but the fluke did give the same reading as the crap ones did for the resistors on the grids. about 438 ohms.

Last I heard you said your tuner tube pin voltages were checking OK per Sams, so any drifted resistors really aren't too concerning to me. But I'm only one persons opinion. To me the bigger issue is you really don't have any good method to check signal strength or substitute a known good signal at various points in your set. Personally I like the convenience of a B&K 1077B Analyst. With one you can substitute a Video IF signal and compare that picture with with what you get connecting to the antenna. Basically you'll be able to substitute signals starting at the CRT and work your way all the way back to the antenna. The catch is these units may also need some repairs made to them. But they are relatively common place and also quite inexpensive if you can find one from some place local to you. Quite literally no one needs them today other that a handful of us hobbyists, so there's no good reason they should be anything but dirt cheap, or even free for shipping.

Last I heard you said your tuner tube pin voltages were checking OK per Sams, so any drifted resistors really aren't too concerning to me. But I'm only one persons opinion. To me the bigger issue is you really don't have any good method to check signal strength or substitute a known good signal at various points in your set. Personally I like the convenience of a B&K 1077B Analyst. With one you can substitute a Video IF signal and compare that picture with with what you get connecting to the antenna. Basically you'll be able to substitute signals starting at the CRT and work your way all the way back to the antenna. The catch is these units may also need some repairs made to them. But they are relatively common place and also quite inexpensive if you can find one from some place local to you. Quite literally no one needs them today other that a handful of us hobbyists, so there's no good reason they should be anything but dirt cheap, or even free for shipping.

looks up " B&K 1077B Analyst"
I remember that thing!
I used to work in a TV repair shop late 90s and the owner had one, it was not used much , but I DO remember the CRT inside in front of the weird pick up tube that you put cells in front of for display output.

and there are some on e-bay
perhaps when I get my tax refund


and true about the tuner, I'm pretty sure that trying to replace anything in it would do more harm than good. :(
There Used to be someone within 50-70 miles from here who fixed/ rebuilt them, but they have not been heard from in some time. "quality tuner service" out of Longview, TX.

Yeah ebay unfortunately is probably about the most inflated place you could get one. Should be $20 maybe 50 tops for a very nice looking one. You really should make sure you get at least the target slide with it. Otherwise the only cable you'll need is a BNC to clip leads. Shipping too is a deal killer now days on test gear. Ask around if there was anyone in your area that used to service TV's. Post a wanted add on FB marketplace if you have an account. Seems to be the latest and greatest place to sell old stuff.

the latest test...

https://www.youtube.com/watch?v=dkHebH7xepU

hooked channel master cm-94444 Balun directly to tuner ( soldered)
added ext RF amp, +15 db

still waiting for other peaking coils and Pot to add the contrast mod.

there is still a slight bit of snow in pic . :(

but is looking better.

I'm hoping that once i hook the 12lp4 up, that the retrace lines will go away, I'm not really sure how they got blanking to work in this thing. :o

but since I am using a "test CRT" and it's not quite right, i guess that is why the lines are there for now.

Most early TVs didn't have any retrace blanking. Ideally, they are watched in a dimly lit room and you adjust the brightness and contrast so they are not visible.

Most early TVs didn't have any retrace blanking. Ideally, they are watched in a dimly lit room and you adjust the brightness and contrast so they are not visible.


It's a shame that no one has come up with a blanking mod for it over the years. :(

the latest test...

https://www.youtube.com/watch?v=dkHebH7xepU

hooked channel master cm-94444 Balun directly to tuner ( soldered)
added ext RF amp, +15 db

still waiting for other peaking coils and Pot to add the contrast mod.

there is still a slight bit of snow in pic . :(

but is looking better.

That actually looks quite respectable. Are you using a DVD player, and have you tried any other signal source? You've definitely come a long way with that TV. :thmbsp:

That actually looks quite respectable. Are you using a DVD player, and have you tried any other signal source? You've definitely come a long way with that TV. :thmbsp:

Yes, it is a DVD player, a cheap one I got a $20 piece of garbage, which I got as a source for working on my CTC-16XL, went ultra cheap so if it was taken out by the HV or whatever, I would not lose anything.
I made the DVDs myself from videos I had on my system so it would be macrovision free.


I put in the contrast mod today, and it does work, not as dramatically as it did in the color set I took it from but it works, most likely cause the CTC-16 has 10v on the cathode at that point, and this thing has about 3v, so perhaps I will put in a larger cap than 50mfd.

I'm hoping that the other 3 peaking coils show up this week, shipped 4/14 from Canada, this pandemic has slowed all mail down :(

I see that at least the cheap LCR meter I sent for is in the country now, and may be here this week.

no idea when the digital RF generator will show up, when it does I can hopefully clear up that last bit of snow.

Well if you haven't already try another RF signal source. It would be something if your snow issues turned out to be caused by a cheap DVD player.

Well if you haven't already try another RF signal source. It would be something if your snow issues turned out to be caused by a cheap DVD player.

the DVD player itself has no RF modulator, they stopped putting those in years ago when things switched over to digital.

got this

https://tinyurl.com/yaez4lm4

hooked into an RF amp to the TV.

It's a shame that no one has come up with a blanking mod for it over the years. :(

Try this:

1. Place a 47k resistor between pin 11(cathode) of the CRT and ground.

2. Connect a .05uf, 630v cap from pin 3 and 4(plate) of the 6K6 vertical output
to pin 11(cathode) of the CRT.

Basically you need a positive going vert deflection pulse at the CRT cathode in order to blank the picture during vertical retrace.

https://www.amazon.com/Craig-Compact-Player-Remote-CVD512a/dp/B00A71YOQI

cheap piece of crap i use for testing.


https://www.amazon.com/gp/product/B007F9XHBI/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

the one hooked to my CTC-16 (video input ) for normal playback

Try this:

1. Place a 47k resistor between pin 11(cathode) of the CRT and ground.

2. Connect a .05uf, 630v cap from pin 3 and 4(plate) of the 6K6 vertical output
to pin 11(cathode) of the CRT.

Basically you need a positive going vert deflection pulse at the CRT cathode in order to blank the picture during vertical retrace.

Tried it, not much change, yet.
as I am suspecting, this is mainly due to the diff in the test CRT ( 8YP4) and the one the set was made for, 12LP4.

And once I do have something built to put this into and mount it safely, the lines should be gone ( I hope )

Typical operation...
12LP4

Anode voltage. 11Kv
Grid #2 voltage 250v
max circuit value,
Grid #1 circuit resistance, 1.5 max meg.

8YP4
Anode voltage. 16Kv
Grid #2 voltage 400v
Grid #1 circuit resistance, 1.5 max meg.

https://frank.pocnet.net/sheets/049/1/12LP4.pdf
https://frank.pocnet.net/sheets/049/8/8YP4.pdf

The video smearing, as someone pointed out, is most likely peaking coils, but I'm STILL WAITING on the 3 that were sent from Canada on 4/15, ( 2 @ 120 uh , 1 @ 93 uh ), I wonder if they will ever show up now...

Do ion traps go bad? ( wear out? )

reason I ask is I have 2, the original one that was with the set, that hardly seems to be magnetic at all anymore, and this NIB one I found off ebay.

https://i.ebayimg.com/00/s/MTIwMFgxNTk5/z/1N4AAOSwiQxdfp0h/$_57.JPG?set_id=8800005007
which seems to be quite stronger :o

got the ultra cheapo Mega328 LCR-T4 tester today, only took over 3 weeks :/

Very disappointing on how it works.
does OK on CAPs and Resistors, but SUCKS on coils,

Was way WAY off by over 40% on 2 new coils 240uh and 180uh,
but what do you expect for so little $?

and the New coils I ordered never showed up. :no:
now have try to find something else, somehow...

Ion traps can loose their magnetic charge. It isn't common but does happen.

Trying again :/
trying to get a LCR meter that's a bit better.

also trying to get coils again from another source
perhaps these wont get lost on the way here :(

19-4120 - 120 uh Peaking Coil, 12k Shunt x2
however, the orig was on a 22k, meaning I will have to stick a 10k in there to keep the circuit tuned?

and again I could only get 1 93 coil :/
19-4093 - Peaking Coil, 93 uh, 10m

No shunt from what I can tell

https://imgur.com/0pAv0eh
I think I know what coil/coils are bad/ damaged, but have not been able to test/ replace yet :(
that 6.8 k resistor was burned to a crisp, (r141) most likely due to that .05 cap being shorted, the 10uf was WAY over 10uf, but not TOO leaky, but that paper cap had gone to crap.

Trying again :/
trying to get a LCR meter that's a bit better.

I have had one of these for about 4 years.

https://www.amazon.com/5000-Handheld-LCR-Meter-accessories/dp/B00S298KJO/ref=pd_rhf_se_p_img_4?_encoding=UTF8&psc=1&refRID=VPH8398E96AREEHMW2Z2

Better than a inexpensive 328 tester... cheaper than a lab quality bench unit.

jr

I have had one of these for about 4 years.

https://www.amazon.com/5000-Handheld-LCR-Meter-accessories/dp/B00S298KJO/ref=pd_rhf_se_p_img_4?_encoding=UTF8&psc=1&refRID=VPH8398E96AREEHMW2Z2

Better than a inexpensive 328 tester... cheaper than a lab quality bench unit.

jr

getting this
https://www.youtube.com/watch?v=piAhl9unCMc

USPS track says that the round 2 of the peaking coils will be here midweek.
But I'm still a bit unsure about what to do about the orig 22k shunt vs new 12k. ( it was the only 120mh I could find )
I have not worked much with these type of things, so I'm not sure what to do.

Do I stick the new one ( 120mh on 12k ) and see what happens? Or stick it in series with a 10k resistor to try and match the orig 22?

...

19-4120 - 120 uh Peaking Coil, 12k Shunt x2
however, the orig was on a 22k, meaning I will have to stick a 10k in there to keep the circuit tuned?



Peaking coils are not sharply tuned, like an IF or tuner coil. The shunt (in other words, parallel) resistor is there to damp the resonance so that you do not get too much peaking / ringing etc. A lower shunt resistor usually just means you will get less peaking and a slightly less sharp picture. You cannot improve this by adding a series resistor.

When you get the coil, if it is physically possible to disconnect one end of the resistor from the coil without mechanically destroying it, you could do that and add a shunt resistor of the specified value.
Edit: I think I misread. If you mean adding 10k in series with the 12k (not in series with the whole assembly), that would work too.


Similarly, if a peaking coil calls for a shunt resistor but the replacement has none, you can just add a resistor in parallel.

I messsed up the preceding answer and had to edit it twice!
Please refresh and read the corrected version - sorry!

Peaking coils are not sharply tuned, like an IF or tuner coil. The shunt (in other words, parallel) resistor is there to damp the resonance so that you do not get too much peaking / ringing etc. A lower shunt resistor usually just means you will get less peaking and a slightly less sharp picture. You cannot improve this by adding a series resistor.

When you get the coil, if it is physically possible to disconnect one end of the resistor from the coil without mechanically destroying it, you could do that and add a shunt resistor of the specified value.
Edit: I think I misread. If you mean adding 10k in series with the 12k (not in series with the whole assembly), that would work too.


Similarly, if a peaking coil calls for a shunt resistor but the replacement has none, you can just add a resistor in parallel.

the coil is lit wrapped around the resistor , i this case, and painted over with colored epoxy.
https://i.ebayimg.com/images/g/HSkAAOxyhS9TiLGB/s-l300.jpg
this is not an exact pic, but it gets the idea across

got the ultra cheapo Mega328 LCR-T4 tester today, only took over 3 weeks :/

Very disappointing on how it works.
does OK on CAPs and Resistors, but SUCKS on coils,

Was way WAY off by over 40% on 2 new coils 240uh and 180uh,
but what do you expect for so little $?
.


Interesting. After you posted you ordered one, I checked mine for accuracy against an ordinarily very accurate Sencore Z-meter.

I found the capacitance value readings of the 328 very accurate from low values to high value electros. I found the resistance readings excellent except for values under an ohm. Strangely, using a different combinations of the three inputs gives different results on low value resistors.

But I found the accuracy of the inductors very close to what the Sencore says they are. The 328 is limited in that it doesn't read below 10uh, but other than that, it was very accurate with inductance compared to the Z-Meter

You can try calibrating the 328 tester. Short the three inputs together, then power on. It will calibrate itself and about half way through will ask you to connect a capacitor over .1uf before it finishes. I used a 4uf film capacitor when I calibrated mine and it's pretty accurate.

John

Edit: I just tried a couple more values. Low value inductors read very accurately, but I just tried a 1mH inductor, and it read 1.02mH on the Sencore, and 1.71mH on the 328. Like yours, not even close, so as far as inductors go, I'd not use this ( I didn't anyway). Resistors over an ohm and capacitors of any value are accurate. I also like how it checks transistors and also automatically identifies polarity and lead configuration.

Still, this doesn't make it totally useless on coils. If there are any other coils in the unit of identical or similar value, you can use the results on a "curve" so to speak.

.

the coil is lit wrapped around the resistor , i this case, and painted over with colored epoxy.
https://i.ebayimg.com/images/g/HSkAAOxyhS9TiLGB/s-l300.jpg
this is not an exact pic, but it gets the idea across

If it's not possible to disconnect one end of the resistor without destroying the coil, then you should just use it as is. Not likely to make a major difference in the result.

2 coils replaced so far, both on the 1st video amp, but no change on the smearing yet, will do the video output next.

But what are the chances this may be caused by the Test CRT?
I mean it being JUST different enough to cause slight problems like this?

...

But what are the chances this may be caused by the Test CRT?
I mean it being JUST different enough to cause slight problems like this?
...

Too many posts to go back and find out what your current setup is - are you connected by long wires to the test CRT? This could cause some loss of high frequencies.

Are you talking about the smears in the video you linked in post #322 (Lost in Space)?

That kind of long smear is not likely from peaking coils. In fact, it doesn't seem to occur uniformly on all parts of the picture, but looks more like a regeneration/oscillation problem. You may want to take an insulated screwdriver and touch various tube pins in the video, IF, and tuner, to see if there's a spot that's sensitive to some extra stray capacitance. Touch the CRT cathode and grid too, to see if they are radiating back into the set.

Are all the required tube shields in place?

Too many posts to go back and find out what your current setup is - are you connected by long wires to the test CRT? This could cause some loss of high frequencies.

they are no longer than about 10-10.5 inches, I did extend the rather short wires on the CRT socket when I re-wired it, but no longer than in most color sets, prob shorter,
https://imgur.com/HM6zCI6
I have the term block in there so I can reconfig it to whatever.

Are all the required tube shields in place?

yeah, all shields are in place.

So I guess the next step with this thing is...
Go through the whole video amp circuit, video detector → video output, and make sure there are no more old resistors left.
This will not make any difference, most likely as 75% have been changed already and the old checked in circuit, but this way I can definitely say it's NOT resistors, will also put in the new coils at the video output stage, ( got them, might as well use them ), will also do a 3rd check of the replaced caps in the area. :/ mostly .05 paper caps (coupling) replaced with film type .047.

When done, I will attempt to use the 12lp4 for the first time, which will be a bit tricky cause I got to work out how to support it safely.

I will most likely try the newer trap, as the old one seems very weak.
There are very detailed instructions about how to put on the ion trap in the RCA 630ts service guide, mentioning “ion trap flags” in the CRT, and lining them up, but it was written for the EM version, not that different but, I am to assume the the arrow stamped in permanent magnet trap is to point to the screen?
https://imgur.com/byyV6dg

been over the video amp section again, and after putting in 2 new coils, found nothing else wrong, other than a 47k res at 55k, replaced, but not the cause.

I do see the same smearing of video no mater if it is input via the tuner or direct input, also, I saw no visual difference in picture when i pulled out the 6AL5 being used as "dc restoration" while watching with video input, and I did swap it with the other 6AL5 from the audio sec, no change.

I'm tending more now to think that this may be due to the diff between the test CRT and the original types.
I wont be able to test this for sure till this weekend or so.

they are no longer than about 10-10.5 inches, I did extend the rather short wires on the CRT socket when I re-wired it, but no longer than in most color sets, prob shorter,
https://imgur.com/HM6zCI6
I have the term block in there so I can reconfig it to whatever.

Your extra long CRT wires and the terminal strip aren't an ideal situation. A lot of manufactures intentionally separated the video wire from the others to eliminate stray capacitance. Personally I would get rid of the terminal strip and shorten those wires. Not a guarantee it will fix all smearing, but what you have there is poor practice considering the frequency response of the video signal.

:yikes::guitar:

WOW!

My guess was right.
I have been chasing ghosts , literately

https://www.youtube.com/watch?v=xJhhr12FFrI

Here it is on the 12lp4.

Not fully adjusted yet, as i don't have a permanent thing to put it in yet, but DAMN!

Hmm..I wonder if maybe you got a flaky test CRT. Can't say I've ever used an 8YP4. I'll assume you knew that you don't use an ion trap with a test CRT. I have no idea what that could do if you did.

:yikes::guitar:

WOW!

My guess was right.
I have been chasing ghosts , literately

https://www.youtube.com/watch?v=xJhhr12FFrI

Here it is on the 12lp4.

Not fully adjusted yet, as i don't have a permanent thing to put it in yet, but DAMN!


Something's wrong. There's some annoying whine that is permeating the sound.

Edit: Never mind, that's Dr. Smith...

John

Hmm..I wonder if maybe you got a flaky test CRT. Can't say I've ever used an 8YP4. I'll assume you knew that you don't use an ion trap with a test CRT. I have no idea what that could do if you did.


i chose the 8YP4 cause it did not need any focus or Ion trap, I did not want to mess with it when I was restoring things.

today was the first time ever setting up an Ion trap :o
and the 8YP4 was used. :O

Something's wrong. There's some annoying whine that is permeating the sound.

Edit: Never mind, that's Dr. Smith...

John

that is the fans in my server..
2 of these

https://www.youtube.com/watch?v=on9pvkJ0P1w

Also you don't use a focus coil with a test CRT. I'm probably stating the obvious but there's no telling what can be overlooked. Never mind, just read you post before mine. Good on you.

Also you don't use a focus coil with a test CRT. I'm probably stating the obvious but there's no telling what can be overlooked.


correct,

that is why I picked it,, of the few that ETF had, it was the only one that I did not have to worry about ion trap and any focus ( automatic ), i just happened to pick the VERY used one, it had scratches and 2 burned spots on the screen.
they still have 1 new on I think.

hmmm

that blanking mod sort of works with the12lp4, but it also caused a shadow to appear on the top of the screen. that was not seen on the test CRT.
Weird :o as seen in the video.

no amount of vert resize would make it go away.
I removed it, hooked cathode back to GND, and its gone...
strange

snip/ paste
Try this:

1. Place a 47k resistor between pin 11(cathode) of the CRT and ground.

2. Connect a .05uf, 630v cap from pin 3 and 4(plate) of the 6K6 vertical output
to pin 11(cathode) of the CRT.

Basically you need a positive going vert deflection pulse at the CRT cathode in order to blank the picture during vertical retrace.
----
Pure speculation at this point, not really sure, the RCA 630ts service manual shows the wave at this point to be 700v ptp, perhaps that was too high for the cathode of the 12lp4 , and some resistor in the line is needed?

A resistor may be needed also adjusting the cap value may help...a good place for decade box engineering.

A resistor may be needed also adjusting the cap value may help...a good place for decade box engineering.


I'm thinking the same...

from another thread...
-----
I often simply hunt for an appropriate waveform somewhere in the vertical oscillator or output stage and couple it through a small value cap to the brightness control of the set. If the video signal is on the CRT cathode and brightness control on the grid, then you want a sawtooth with a rising ramp and a vertical drop. If the video is on the CRT grid and the brightness is on the cathode, then you want a signal with a falling ramp and a vertical rise. Depending on the amplitude of the signal you are grabbing, something in the range of 50 - 1000 pF will usually do it, and typically you need to add about 50-100 K in series with the lead to the cathode or grid, and couple the signal to the cathode or grid end of the resistor.

I've had a few sets where this was not successful. Sometimes the problem is that the sawtooth rise or fall is too fast, and the retrace on the screen isn't done before the blanking pulse ends. The method shown here should solve that problem, since it pulls the blanking pulse off the actual current waveform in the vertical deflection yoke. I'll keep this circuit in mind for future reference!
-----

and seen in almost every RCA color set, CTC 10-20 , and so on.
https://imgur.com/ZH3uckS
I may try something more like seen here.

IE, VERT OUT-- RESISTOR -- CAP - RESISTOR -- CRT CATHODE --- RESISTOR-- GND

Something's wrong. There's some annoying whine that is permeating the sound.

Edit: Never mind, that's Dr. Smith...

John


that is the fans in my server..
2 of these

https://www.youtube.com/watch?v=on9pvkJ0P1w


Swing and a miss...

:(


John

Swing and a miss...

:(


John

Yes, I do know what you meant, I happen to like the new Dr Smith better BTW, (June Harris)

I just happen to be of the school of when you turn on your PC, and if it does NOT need to be nailed down or glued to a horizontal surface to keep it from taking off like a 747, then you DON'T HAVE ENOUGH fans in it!! :D

Yes, I do know what you meant, I happen to like the new Dr Smith better BTW, (June Harris)

I just happen to be of the school of when you turn on your PC, and if it does NOT need to be nailed down or glued to a horizontal surface to keep it from taking off like a 747, then you DON'T HAVE ENOUGH fans in it!! :D

Lol.
For my media PC I bought the quietest fans and case I could get for sane money and sized the heatsinks 2X the wattage the CPU etc would be able to put out....the result: my fans barely need to run under heavy load, don't make audible noise and if my fans die and I don't hear it the heatsink alone will prevent calamity and allow normal opperation under normal use.

Yes, I do know what you meant, I happen to like the new Dr Smith better BTW, (June Harris)



Okay.

I feel a little better I guess. :tears:

So hard being an internet comedian. The pay is lousy and most people just flat out think you're nuts..:screwy:

John

server specs...
NOT , my main system, not my media system...
Just the server...
Yes i have many PCs.. :o

LSI MegaRAID SATA/SAS 6Gb/s PCI-Express 6 port
WD Red Pro 2TB NAS Hard Disk Drive - 7200 RPM Class SATA x4
WD Black 3TB Performance Desktop Hard Disk Drive - 7200 RPM SATA x2
Crucial M4 2.5" 256GB SATA III MLC Internal Solid State Drive (SSD)
pioneer BDR-208DBK
gigabyte GA-970A-DS3P mobo.
amd vishera FX-8320
G.SKILL Ripjaws X Series 16GB x2 DDR3 1600 (PC3 12800) total 32 gig
CORSAIR RM Series RM650 CP-9020194-NA 650W
EVGA GeForce GT 710 DirectX 12 01G-P3-2711-KR 1GB 64-Bit DDR3 PCI Express 2.0
RAIDMAX SMILODON ATX-612WBP Black 1.0mm SECC Steel ATX Mid Tower Foldout MB Computer Case
3 vantec tornado 80mm
2 vantec 120 mm

I'm thinking the same...

from another thread...
-----
I often simply hunt for an appropriate waveform somewhere in the vertical oscillator or output stage and couple it through a small value cap to the brightness control of the set. If the video signal is on the CRT cathode and brightness control on the grid, then you want a sawtooth with a rising ramp and a vertical drop. If the video is on the CRT grid and the brightness is on the cathode, then you want a signal with a falling ramp and a vertical rise. Depending on the amplitude of the signal you are grabbing, something in the range of 50 - 1000 pF will usually do it, and typically you need to add about 50-100 K in series with the lead to the cathode or grid, and couple the signal to the cathode or grid end of the resistor.

I've had a few sets where this was not successful. Sometimes the problem is that the sawtooth rise or fall is too fast, and the retrace on the screen isn't done before the blanking pulse ends. The method shown here should solve that problem, since it pulls the blanking pulse off the actual current waveform in the vertical deflection yoke. I'll keep this circuit in mind for future reference!
-----

and seen in almost every RCA color set, CTC 10-20 , and so on.
https://imgur.com/ZH3uckS
I may try something more like seen here.

IE, VERT OUT-- RESISTOR -- CAP - RESISTOR -- CRT CATHODE --- RESISTOR-- GND

By all means feel free to experiment. Adding a series resistor is a good place to start. Every set is a little different so there's no exact science.

here it is w/o the shadow at the top
https://youtu.be/Fi4C6_bdXJk

now come the tough part,, trying to put it all into something :o

I just closely checked the coils I removed from the set, the 2 120uh coils, L22, L20 (wrapped around a 22k res) seemed to compare mostly OK to to new ones, but today, when removed the wax from them so I can open the coil on one end to measure the resistor, the core resistor from L20 tested at 52k and L22 at 31k. :yikes:

At this point, I have only replaced 4 out of 6 coils, for video amp and output, have not touched video det yet, which has a 180uh coil around a 39k, this one most likely has also drifted up. :(

https://www.youtube.com/watch?v=xGH3LW2gUwE

retrace mod adjusted

vertout--100k--.01uf--56k---CRTcath---47k---gnd

front section done (almost, sanding and painting still needs to be done )
https://imgur.com/l89X293
:banana:

this took a while, a few missteps, but came out OK!

first test fitting

https://imgur.com/YaNjW2E
https://imgur.com/xAz5lG8
https://imgur.com/6deGCHw
https://imgur.com/PymKJqn

Still gotta do some sanding, find paint that matches the CRT cover color, perhaps add some trim around the edges on the front, and get a clear plexyglass top.
also,make a opening for the speaker when I get it.

I now have a spare FBT for this set (Ram XO-36) in my paws, it came today! :o

I never would have guessed that one for this would be easier to get than one for a CTC-16XL :/

And even though this thing is "NOS", there are already tiny cracks in the "doughnut" on it, but I don't think that really matters much. :p

The CTC-16 and a good number of color RCAs were notorious for eating flybacks but Zenith and a number of other brands almost never blew a fly....go back to the late 40s and it was the other way around....

here it is with knobs and faceplace
https://imgur.com/2A81IVs

Nice!

The CTC-16 and a good number of color RCAs were notorious for eating flybacks but Zenith and a number of other brands almost never blew a fly....go back to the late 40s and it was the other way around....

Zeniths were pretty good about flybacks, and RCAs from the early 60s until the XL-100 came out about 1971 were tough on them.

But, Zeniths were prone to yoke failure wheras we NEVER saw an RCA color yoke fail ever.

John

now painted

https://imgur.com/AWn6Qn3

however, due the current virus situation, there has been a run on plexiglass, and it's hard to get in large pieces, and thus the prices have gone WAY up, i couls only get too big or too small, the piece I got was $30, to get larger would have been over $80, and I would have had to cut a good part of it off to cover the entire top, so I did the best with the smaller. :/

Zeniths were pretty good about flybacks, and RCAs from the early 60s until the XL-100 came out about 1971 were tough on them.

But, Zeniths were prone to yoke failure wheras we NEVER saw an RCA color yoke fail ever.

John

By the early 50s Zenith flybacks were solid , but the late 40s early 50s flybacks found in Zenith portholes were fairly high failure...worse than the contemporary 630 RCA variants.

By the early 50s Zenith flybacks were solid , but the late 40s early 50s flybacks found in Zenith portholes were fairly high failure...worse than the contemporary 630 RCA variants.

Before my time Tom, before my time. I had heard of the legendary 630 by the old timers in the TV trade when I was the young gun in the 70s helping the old guys with transistors, but had never seen one until maybe 10 years ago at a swap meet. My dad was fond of servicing them.

But I remember my dad and older brother replacing flybacks on RCA color TVs we sold that were still within warranty - the nastiness peaking about 1968 or so. Back then, RCA supplied parts, but did not pay labor to servicing dealers.

Getting off the topic a bit, but I remember when RCA introduced the XL-100 in 1971, they allowed the owner to have *any* service company repair an XL-100 in warranty. That was short lived and they went back to standard ASCs a year or so later.

John

what I don't really get is, why is something with a 12 inch diameter CRT limited to being hidden behind a 7.5 x 10 in window? :o
could it not have been a bit bigger?

what I don't really get is, why is something with a 12 inch diameter CRT limited to being hidden behind a 7.5 x 10 in window? :o

Probably to restore the lost corners of the picture, albeit at the cost of a smaller pic. Just guessin'. :nerd:

Probably to restore the lost corners of the picture, albeit at the cost of a smaller pic. Just guessin'. :nerd:

Those corners come at a cost of a considerably smaller picture size...compare these two GE sets that have 10” round CRTs.

http://www.videokarma.org/attachment.php?attachmentid=170160&d=1302897431

jr

Before my time Tom, before my time. I had heard of the legendary 630 by the old timers in the TV trade when I was the young gun in the 70s helping the old guys with transistors, but had never seen one until maybe 10 years ago at a swap meet. My dad was fond of servicing them.

But I remember my dad and older brother replacing flybacks on RCA color TVs we sold that were still within warranty - the nastiness peaking about 1968 or so. Back then, RCA supplied parts, but did not pay labor to servicing dealers.

Getting off the topic a bit, but I remember when RCA introduced the XL-100 in 1971, they allowed the owner to have *any* service company repair an XL-100 in warranty. That was short lived and they went back to standard ASCs a year or so later.

John
I was born in 1991 and and work on pretty much anything/everything TV/radio/audio made before 1976 so everything I fix is before my time...It all fascinates me so I try to learn as much as I can about everything.

I was born in 1991 and and work on pretty much anything/everything TV/radio/audio made before 1976 so everything I fix is before my time...It all fascinates me so I try to learn as much as I can about everything.
I retired from the trade vocationally in the mid-'80s, never dreaming that someday I'd be able to do the same stuff 'vicariously' thru a yet-uninvented magic medium.

https://imgur.com/a/pdV17xU

speaker hole added ( and speaker), and speaker cloth.

once I get that face-plate put on for real, not just laid in place, will add trim at top and bottom of speaker cloth, but the face-plate must be centered on CRT first.

https://www.youtube.com/watch?v=Wo1TIaGsA-Y

here it is in the enclosure with a real speaker

https://imgur.com/a/pdV17xU

speaker hole added ( and speaker), and speaker cloth.

once I get that face-plate put on for real, not just laid in place, will add trim at top and bottom of speaker cloth, but the face-plate must be centered on CRT first.

Looks and sounds very good.

Amazing what an enclosure can do for a speaker. :)

Seems like the picture should be a little wider, but you'll figure that out when you get the mask on there permanently.

Looks and sounds very good.

Amazing what an enclosure can do for a speaker. :)

Seems like the picture should be a little wider, but you'll figure that out when you get the mask on there permanently.

it is wider, there was a wired AR issue when i made the DVD.

A test fit with all pieces in place

https://imgur.com/3uZPZqv

still have to do final paint touch up, after final placement adjustments, which will have to wait till I get small wood bits for dremel tool to make final trimmings.

I did manage to nab a REAL rf modulator, https://tinyurl.com/y8hqmz7u ( channel 7 ) , I just have to rig up a way to get power into it, +12 & +5, should work much better than the basic crap one I have now.:banana:

https://imgur.com/vJ1cEe9

the BT mod came a lot faster than expected :o

Harlock had to go sneak into the pic! =^-^=

:D:yes:

I think I found my target for restoration in 2021!
https://tinyurl.com/ycrcm7c4

I don't have it yet, but I will try!

I did manage to nab a REAL rf modulator, https://tinyurl.com/y8hqmz7u ( channel 7 ) , I just have to rig up a way to get power into it, +12 & +5, should work much better than the basic crap one I have now.:banana:

The picture shows ch6...
If it is that could be better. The audio for CH6 is at the bottom of the FM band and most FM radios can tune it (there are even analog TV stations opperating more as radio stations because of this). You could use it as both TV station and radio station if you want.

Cute cat BTW. Some of the most affectionate cats I've met were black cats.

The picture shows ch6...
If it is that could be better. The audio for CH6 is at the bottom of the FM band and most FM radios can tune it (there are even analog TV stations opperating more as radio stations because of this). You could use it as both TV station and radio station if you want.

Cute cat BTW. Some of the most affectionate cats I've met were black cats.

I just used that one as "stock Picture" , before I had mine in hand, mine is chan 7, I WAS focused on the unit, but then kitty jumped in and stole the scene (and focus )
I ordered it on sat, and had it on Mon. even though eBay said it would be here Thurs. :o

I guess since the conversion to digital cable, these things have become “obsolete” and thus so easy to find so cheap everywhere.

:D:yes:

I think I found my target for restoration in 2021!
https://tinyurl.com/ycrcm7c4

I don't have it yet, but I will try!

it seems this is a rare / unusual TV.
stromberg Carlson X-21 M4B
mentioned here
http://www.earlytelevision.org/pdf/rider-67.pdf
I just have to go get it some time.
:D

https://www.youtube.com/watch?v=FMH5KJL602Q

latest test, ran it for about an hour.

Still have slight IF problems.

tuner is still dirty, have to go in and scrub contacts, spraying cleaner in and rotating it did not clean it enough.

this was with the BT modulator on channel 7.
still need to adjust Horz width a bit.

Cell cam SUCKS for taking video :(

For some reason, the horz width adjustment had very little affect, I doubt that the coil is bad, I may start with changing the two caps that they stuck in there to mod it for the 12 inch CRT.

Sent from my VS501 using Tapatalk

https://imgur.com/J6m643k

I'm still not sure what these 2 caps do, but they are ONLY on the version with the 12 inch CRT, not the 10, so I assume it has to do with making the scan wider.
As mentioned, adjusting the width coil seemed to have no effect, not sure why, I doubt that it's open, but who knows.
I have 2 new caps ordered, mouser # 505-FKP1220/2000/10 , will take a close look at coil when I put them in.

edit...
a pic of the old caps from when I had the FBT out of the set.
https://imgur.com/qw1tylZ

The width coil typically has only minimal effect. It's meant for fine tuning the width. Maybe an 1/8" - 1/4" of an inch from one extreme to the other.

Well, the caps are already ordered, so I might as well put them in, for better , or worse.
I now see why they have 2 220pf caps in series, cause 110pf seems to be a VERY odd cap, and is hard to get, even now, not in stock with very long wait time to get if you try.

Putting two in series may be a voltage stress thing too, so better to do it their way.

I decided to haul out the LD payer and run a movie or two.

https://imgur.com/Z28QFrd

Today's test

One thing I have noticed running this set, the audio on it can get VERY loud, surprisingly so.
Also, tuning is quite finicky, always having to tweak fine tuning to get best picture as it warms up, (herringbone patterns that never fully gos away ), not sure if this is a tuner problem ( age/ dirty contacts ) or if it's IF related, namely the new 1st IF coil 23.3mhz and trap 27.25mhz, which I was unable to get good results the first attempt going by the book to adjust it, and did it by “eye'..

One thing that will help is to eliminate the color sub carrier from the video going to your modulator.
On an LD player if there's an S- video output make an RCA adapter cable that only connects to the monochrome coax in the S-video coax pair. Newer component video sources just use the green Y video cable.
Many monochrome sets made before color TV was standardized had video response out to 4.5MHz later sets limited the video IF bandwidth to ~3MHz to hide the chroma dot crawl.

One thing that will help is to eliminate the color sub carrier from the video going to your modulator.
On an LD player if there's an S- video output make an RCA adapter cable that only connects to the monochrome coax in the S-video coax pair. Newer component video sources just use the green Y video cable.
Many monochrome sets made before color TV was standardized had video response out to 4.5MHz later sets limited the video IF bandwidth to ~3MHz to hide the chroma dot crawl.

not on my player :(

http://www.laserdiscarchive.co.uk/laserdisc_archive/pioneer/pioneer_ldv-8000/pioneer_ld-v8000.htm

edit- notice the wt... almost 35lbs :o

But I do have one of these...
https://i.ebayimg.com/images/g/grkAAOSwPwVemGtC/s-l1600.jpg

I can cut the color out completely.

But I do have one of these...
https://i.ebayimg.com/images/g/grkAAOSwPwVemGtC/s-l1600.jpg

I can cut the color out completely.

It would be interesting to know how it adjusts the color level; specifically, does it involve a low pass filter that also attenuates high frequency detail?

another day, another LD.

https://imgur.com/mMXcECv

I def have to clean that tuner dome some :(
And I am betting sound in the picture still.
I did try to clean the tuner a while back, with deoxit, and ran through the channels a few times, but it was obviously not enough, for example, with the BT modulator, (CH7) , when I tune to 7, I get nothing when it "clicks" into position, I have to turn it slightly out of position to get it to get the signal in, so it seems the contacts are still dirty for chan 7, and who knows about chan 9, the IF alignment instructions said to remove the OSC tube and turn to chan 9, so perhaps 9 has dirty contacts too still.
and that's why I had problems with the IF setup :(

I do have I can of RadioShack Control/Contact Cleaner and Lubricant coming, that I hope to clean it up better.

and then perhaps I can try to adjust the 1st IF again

it seems that once I cleane the tuner a bit more, I will have to adjust more than the new 1st IF coil and trap...

as mentioned. I have seen sound in the picture.
but that trap has nothing to do with that.

https://imgur.com/p7bwi4X

this info is only in the RCA guide, the sams does not say what the traps do.

the trap on the 1st IF is for adjacent channel sound, of which there is none...

the sound trap is an another adjustment :/

today's movie

https://imgur.com/mPmo6pq

and as I guessed (and was told ) , trying to adjust the traps by eye does not really get me anywhere :/

so will have to wait till later after I get the cleaner, and I recover from shoulder surgery and can lift things again :(

I now have a RF generator that I can have precise control over , freq and amplitude, unfortunately, the tuner cleaner did not come today as hoped, meaning it will be here Monday or later, (USPS is very slow lately ) meaning I won't be able to attempt to do it until Aug, most likely after I have recovered and can lift things again w/o risk of ripping the things they are trying to fix in my shoulder :(

there is still one thing about the alignment setup I am unsure of.
where as it says Channel 9, in though the aut inputs and gives exact setup for setting RF gain via "contrast " at -3 volts, and what freq to use for each coil trap adjusted, it does NOT mention what amplitude to use, I can select any range from 00.000v to 10.000, so what would be needed to do this?
has anyone done this before and know the right range to use?

screenshot of the PC interface for the RF generator
https://imgur.com/lwu3fZK

there is still one thing about the alignment setup I am unsure of.
where as it says Channel 9, in though the aut inputs and gives exact setup for setting RF gain via "contrast " at -3 volts, and what freq to use for each coil trap adjusted, it does NOT mention what amplitude to use, I can select any range from 00.000v to 10.000, so what would be needed to do this?
has anyone done this before and know the right range to use?


In general the lowest amplitude that allows you to make a reliable measurement. Since your TV doesn't have AGC you don't have to worry about that messing with your signal level. The one thing you want to avoid is overloading the IF amplifiers.

In general the lowest amplitude that allows you to make a reliable measurement. Since your TV doesn't have AGC you don't have to worry about that messing with your signal level. The one thing you want to avoid is overloading the IF amplifiers.


I'm going to start with the traps only, cause the RCA service manual says to do them first, and I'm mostly seeing sound and noise in the pic.

For RF input, a couple of millivolts up to a tenth of a volt should do. If the instructions say to set the contrast/gain to a certain fixed value, do that and adjust the input level up from zero until you get a few volts (2 to 4) out of the video detector. If you have information on what the usual video amplitude is out of the video detector, go for that instead.

A note on the use of a fixed AGC/gain voltage:

Changing the bias of the RF and IF amplifier tubes to adjust signal gain can affect the tuning of the stages. In the earliest sets, it is likely that the designers tried to minimize this or just lived with it - hence, the best procedure in alignment was to use a specified bias instead of a specified input signal level.

When designers later got this effect understood and under control, they designed IF amplifiers for black and white sets that deliberately changed response at low signal conditions to roll off the high video frequencies (low IF frequencies), thereby reducing noise ("snow") in the picture. In these sets it is even more important to use known bias and hence strong signal conditions that do not produce the roll-off when aligning the IF.

Finally, when color came along, designers had to minimize any response shift, which could have attenuated the color signal. Still, it was good practice to align the IF under specific fixed bias conditions, so any undesired variations would occur from there and not some random conditions that the technician happened to use.

here is how SAMs says to do it
https://imgur.com/HpMK2wJ

Looks like they're depending on IF frequencies getting through the tuner. If that doesn't work, they send you to connect at the mixer grid. This means that everything from the mixer output to the video detector cannot accidentally be loaded/detuned by your signal connection. It also probably means you will need greater signal level than I mentioned above, because I thought you were inputting a channel 9 RF sweep.

On a unrelated note, I have secured the Stromberg Carlson X-21 M4B, for restoration project 2021, I don't HAVE it yet, but it's paid for, and I just have to go get it once I'm able to drive again.

This does bring up an odd question, what does one DO WITH all these old sets when done? You tend to run out of places to display them all when done! :p

And, it seems that restoring stuff is like a drug addiction, heroin or crack cocaine, the more you do, the more you want!:D

I wish Photobucket would let me navigate to the picture of my wall of color sets from the years when I was stuck in a small apartment room.

I've learned to stack and or shelve stuff. I literally have walls of sets that I can turn on and watch...I've been known to watch the same show on 3 sets at once, or 3+ different shows at once. It's sort of like the old intros to robot chicken. :D
Once I buy my own home and am not limited to the basement, my bedroom and display room I'll probably be set up like Walter Matheaus character in Grumpy Old Men where I can walk half way across the house and not have my eyes off the program on some TV. :D

I do actually sell off stuff. I reevaluate my collection and sell off the bottom 10% of things on the likeability scale and or things that don't fit themes or categories I want to collect. The ETF is my primary selling ground, though the radio clubs within 3 hours drive of me sometimes result in TV sales...I collect radios too and bringing TVs to radio meets sometimes gets leads on TVs and other stuff.
I'm at the point where with ~100 sets I'm happy with what I have and have almost stopped buying new stuff/gotten pickey.

The stromberg carlson x-21 seems to be an interesting set, (been looking at the SAMS)

It's clearly more power efficient than the RCA 630ts, needing only 1 5u4g vs 2, the set has 2 speakers, 1 in front, 1 side, it uses 1 of those compact resistor / capacitor modules, and it has an option for phonograph input ( ceramic ), the dual switch changes audio to ext input, and kills HOT output via cathode, and thus vertical scan through boost.
https://imgur.com/Iv55YPT

my surgery went OK, and now my arm is hanging off me like a dead fish, due to the nerve block. So now i wait for it to wear off and the horrid post op pain to start, and the 2 weeks of aggressive PT to follow. :yikes::saywhat:

my surgery went OK, and now my arm is hanging off me like a dead fish, due to the nerve block. So now i wait for it to wear off and the horrid post op pain to start, and the 2 weeks of aggressive PT to follow. :yikes::saywhat:

Ouch. Hope your recovery goes fast and well.

Sitting around waiting for PT later today, I was watching some Trek fan episodes, and in ep#2 of "Space Command,The Greatest Star Trek Series You're Not Watching "

I spotted something VERY familiar ! :D


https://imgur.com/8SJBu3V

alignment question...
In the sams, it says that if you are doing an IF alignment with CRT removed, to remove V22( horz osc ) to disable HV, but in the many videos I have seen, (mostly shango066 stuff ) , that this is bad, as it can cause the HOT to over bias and melt down w/o being fed an osc source.

this chassis has S2 ( fuse 2) which is easy access under side, that cuts power from the damper cathode to the FBT primary, would not pulling that be a safer easier way to disable HV than to remove the horz osc tube?

Tuner cleaning was unsuccessful, after using RS contact / tuner cleaner on it, and aggressive changing channels for several minutes, there is no change in how well channel 7 is working, I am still having to rotate quite a bit far away from the "click " for that channel for it to come in correctly and there is something wrong with the contacts in the tuner in that area, and 2 cleaning attempts have not helped, this is also probably having an impact on channel 9, and preventing me from doing a proper IF alignment, so rather then trying to figure out what is going on with the tuner, I think the best way to go ahead is to do direct A/V input.

Sent from my VS501 using Tapatalk

If that's a Standard brand tuner it seems there may be a slot in the clunk roller mounting bracket so you can fine tune the contact alignment?

Could be it has the same multi-deck wafer rotary switch as the RCA 630. Not sure why that would affect the IF alignment ?

Could be it has the same multi-deck wafer rotary switch as the RCA 630. Not sure why that would affect the IF alignment ?

it has the exact same multi-deck wafer rotary switch as the RCA 630.

and where as I did not see the problem on channel 3-4, I only became aware of it after I got a BT modu which is set to channel 7,
and as mentioned, I can only get chan 7 to come in if I turn the turner off the indent and into between 7-8 .

I'm highly suspecting this is contact problems that 2 cleanings did not help, and did not seem to effect chan 3-4.
the reason it may be affecting IF alignment is, the way is is said to do it on this set is to turn to channel 9 and feed in a signal from a RF generator, I have tried this 2 times with a old analog generator (Eico 324) and have not been able to complete the process, signal input had no effect on meter, I had thought this may because the Eico 324 was not exact enough, or something, but I now suspect hat chan 9 may also be flaky, and without any way to test it, I have no way to know if it works correctly to even try using it for IF alignment.
if there was a way to do IF alignment that did NOT feed a signal trough the tuner on chan 9 with this set, I'd try it, but there does not seem to be one...

and so I'm now direct input.
https://www.youtube.com/watch?v=pTZ2pWFNQCE
camera still sux :/

I really found no way to adjust the clunk roller mounting bracket ,

what it would take is something along the lines Phil Nelson did in his GE 810 TV Restoration, https://antiqueradio.org/GE810Television.htm - Tuner Cleaning Redux
same sort of problems, but at this point, its not worth it for me to pull it out to get to it all to clean it. :(

The contacts for channel 7 may be damaged and no amount of cleaning will fix it. I don't see why you couldn't use another channel for alignment but I don't know this set.
From the video it looks like you might have a noise or interference problem in the video signal.

The contacts for channel 7 may be damaged and no amount of cleaning will fix it. I don't see why you couldn't use another channel for alignment but I don't know this set.
From the video it looks like you might have a noise or interference problem in the video signal.

I took it off a crappy cellphone cam, it does not work very well for this, the noise is the cam trying to auto adjust :(

Per Sams have you tried injecting your test signal direct to the mixer grid? With the oscillator tube removed and signal connected to the mixer grid there should be no reliance on channel selection, because the mixer is post any channel tuning. You could also inject the signal to the shield of the mixer, keeping the shield insulated from contacting the chassis.

If your rf generator is not perfectly calibrated to your sets IF you should be able to rock the generator tuning and find out where the signal gets through to the detector. You know the IF is working at some frequency or you wouldn't have been able to watch channels 3-4.

Like Kevin said above, when you align the IF, you inject the signal after the Rf front end. The tuner won't have any effect. The typically have you disable the local oscillator or switch to an unused high VHF channel to avoid an external signal getting in. Probably why they suggest channel 9.

Like Kevin said above, when you align the IF, you inject the signal after the Rf front end. The tuner won't have any effect. The typically have you disable the local oscillator or switch to an unused high VHF channel to avoid an external signal getting in. Probably why they suggest channel 9.

https://imgur.com/HpMK2wJ

the 2 times i tried, I tried going in via the ant input as it said, after the 2nd try, I found that having the freq generator hooked up had no impact on the voltage level at the point being measured, nor did changing freq slightly.

i did not however try as Kevin mentioned, tapping it in on point E, if I do try again, I will most likely go that route, but as mentioned, my contacts for chan 7 are most likely damaged, and to make things work I have to go with a mod I can pic the chan output on to get the most clean pic,, 3-4 DID work, but had a lot of RFI, most likely all the computers i have :(
so hopefully once I can get the IF setup ( mostly the 1st IF and traps ) i can use a modulator like this,https://www.amazon.com/fosa-Modulator-Converter-Amplifier-Satellite/dp/B07G9ZYXW9?th=1
and find the best working channel
till then, I will use direct input, will try to get a better video tonight.

https://imgur.com/HpMK2wJ

the 2 times i tried, I tried going in via the ant input as it said, after the 2nd try, I found that having the freq generator hooked up had no impact on the voltage level at the point being measured, nor did changing freq slightly.

i did not however try as Kevin mentioned, tapping it in on point E, if I do try again, I will most likely go that route, but as mentioned, my contacts for chan 7 are most likely damaged, and to make things work I have to go with a mod I can pic the chan output on to get the most clean pic,, 3-4 DID work, but had a lot of RFI, most likely all the computers i have :(
so hopefully once I can get the IF setup ( mostly the 1st IF and traps ) i can use a modulator like this,https://www.amazon.com/fosa-Modulator-Converter-Amplifier-Satellite/dp/B07G9ZYXW9?th=1
and find the best working channel
till then, I will use direct input, will try to get a better video tonight.

Speaking of computers generating RFI... everytime you bring in another modern signal processing device you'll more than likely be dealing with yet another switch mode power supply and micro controller generating even more RFI. Something to think about. :scratch2:

so hopefully once I can get the IF setup ( mostly the 1st IF and traps ) i can use a modulator like this,https://www.amazon.com/fosa-Modulator-Converter-Amplifier-Satellite/dp/B07G9ZYXW9?th=1
and find the best working channel
till then, I will use direct input, will try to get a better video tonight.

I've never noticed that modulator before. Are you sure it doesn't output a digital modulated signal. The ad does mention NTSC but the device also looks to have a RF input that it may apply to. The display shows 5.38 which is too low to be in MHz, so it looks like it is set to digital channel 5.38.

here it is on a webcam
https://youtu.be/HgqNDAEh-Wc

a bit better.

for that modulator, the question was asked,,, digital or analog

and the reply.
Analog, NTSC Mono. The Information Sheet that comes with the unit includes a Frequency Table for the channels used with USA cable systems, of which, the first 13 channels are the same as over-the-air broadcast analog channels.

I've never noticed that modulator before. Are you sure it doesn't output a digital modulated signal. The ad does mention NTSC but the device also looks to have a RF input that it may apply to. The display shows 5.38 which is too low to be in MHz, so it looks like it is set to digital channel 5.38.

ATSC and QAM capable modulators are $1K at cheapest and only used by broadcasters and some Ham radio opperators with deep pockets.

Oddly enough, the RFI that is seen on chan 3-4 on the FADA, is also seen on my CTC-16XL, but not the CTC-90.
If it is, it's not noticeable.

Oddly enough, the RFI that is seen on chan 3-4 on the FADA, is also seen on my CTC-16XL, but not the CTC-90.
If it is, it's not noticeable.

I'm not sure what you find odd about that? At any rate you should not consider it a fault of your vintage TV. The fix is unplugging the offending modern noise sources. :D

I'm not sure what you find odd about that? At any rate you should not consider it a fault of your vintage TV. The fix is unplugging the offending modern noise sources. :D

I'm not trying to fault the vintage stuff per sey, just more sort of curious, is tube tech more susceptible to RFI? Or solid state less, or a combo of both?
I have only had the 2 recent tube tech ones to reference recently so I'm not sure.

And since my computers ( main systems & server & home ent system ) are part of what I use on a day to day basis, it's unlikely they will be shut off any time soon! :p
Not to mention the networking systems, both wired in wall and wi-fi, modem, router,hubs etc :0

Anyway, so far my FADA has been run now for about 16-18 hours w/o any problems, the last few with direct input.
Aside from perhaps making another stab at IF alignment someday, the only other thing I'd like to try again is vert blanking mod, after I was not happy with the first 2 tries.

Looking at the SAMS for the SC x21 the I will be getting, I thought perhaps I could use the circuit they have.
https://imgur.com/gVpu2B8

As this sort of worked, but had a black band at the top of the screen.
===
1. Place a 47k resistor between pin 11(cathode) of the CRT and ground.

2. Connect a .05uf, 630v cap from pin 3 and 4(plate) of the 6K6 vertical output
to pin 11(cathode) of the CRT.
======
the RCA manual shows it to be 700v there on the plate of the vertical output, ( a bit high I would think to use here ) and 60v in the yolk.

If I were to try to use the input signal to the yolk as source, do I still use 47k to gnd on the cathode?
or perhaps a 100k pot, and adjust for best results?
and the cap, use one? and just try diff values to see what works?
or more like above in the x21, 2 in series with a pulldown midway.

So many choices :o

"... is tube tech more susceptible to RFI? Or solid state less, or a combo of both?"

If it is radiated RFI, sets with 300 ohm twin lead feeding the tuner will be more susceptible than sets that are 75 ohm coax all the way. Beyond that, it depends on a lot of little tuner design differences that could go either way.

If it is conducted RFI, it all depends on individual chassis design, old or new. This can be reduced with an AC line filter.

I'm not trying to fault the vintage stuff per sey, just more sort of curious, is tube tech more susceptible to RFI? Or solid state less, or a combo of both?
I have only had the 2 recent tube tech ones to reference recently so I'm not sure.

And since my computers ( main systems & server & home ent system ) are part of what I use on a day to day basis, it's unlikely they will be shut off any time soon! :p
Not to mention the networking systems, both wired in wall and wi-fi, modem, router,hubs etc :0

I suppose it all comes down to priorities then. It's technically possible to both transmit and receive a high fidelity AM radio signal, but you probably wouldn't ever consider it enjoyable while listening during a lightning storm.

ooops!
I missed a couple :(

I thought they were Mica :/

I plugged it in tonight and it went FOOM! :O

https://imgur.com/5O76o0O
https://imgur.com/N9UhRBD
one of the 2 input caps went up in smoke, and took the input plug with it, unwelded it from the back.

https://i.imgur.com/xaPGUjl.jpg
so I had to feed a line direct in and add new caps :o

https://imgur.com/8XubId2

back running again

ooops!
I missed a couple :(

I thought they were Mica :/

I plugged it in tonight and it went FOOM! :O

https://imgur.com/5O76o0O
https://imgur.com/N9UhRBD
one of the 2 input caps went up in smoke, and took the input plug with it, unwelded it from the back.

https://i.imgur.com/xaPGUjl.jpg
so I had to feed a line direct in and add new caps :o

https://imgur.com/8XubId2

back running again
My policy on anything pre 1960 is to look up all domino caps on the schematic and replace all rated at 1000pF higher. 1000pF is the threshold where dominos go from usually mica dielectric to usually paper dielectric. The paper dominos also usually have a white dot on them...If there's not a 9 in the capacitance and the capacitance is close to the paper cap range I also consider changing caps.
I've seen blown micamold paper line bypass caps that blew before my ownership before... always a mess.

Watching Card Captor Sakura I see.

My policy on anything pre 1960 is to look up all domino caps on the schematic and replace all rated at 1000pF higher. 1000pF is the threshold where dominos go from usually mica dielectric to usually paper dielectric. The paper dominos also usually have a white dot on them...If there's not a 9 in the capacitance and the capacitance is close to the paper cap range I also consider changing caps.
I've seen blown micamold paper line bypass caps that blew before my ownership before... always a mess.

Watching Card Captor Sakura I see.

Well, I started to run out of LD movies to play while testing, so I went to my original stock of CCS LDs .
And, DO have them all, as I fansubbed the entire series in the 90s :)

I found a " Dunsel "

An old Blonder Tongue Ultraverter Dunsel to be exact!
https://www.ebay.com/itm/201511735381?ViewItem=&item=201511735381

Obviously, it can never be used for anything even if it ever works again, but it's just too unique not to have!

Well, just for grins and giggles, you could use it to convert a digital UHF to VHF and then receive it with a digital receiver or converter box.

If it is still working and you have an agile modulator transmitting at UHF you could hook it to your 630 clone or your Setchell (or was it Stromberg? :scratch2:) Carlson.

I have a few of that things cousins near my work bench. I forget if their gutted or not...I've got roughly 4-6 UHF converter and or VHF antenna amps and 1-2 or the ones I bought were gutted by their previous radio collector owners... one day I'm going either built an AM transmitter in or a clone of a vintage tube RF modulator I bought from the ETF a few years ago.

If it is still working and you have an agile modulator transmitting at UHF you could hook it to your 630 clone or your Setchell (or was it Stromberg? :scratch2:) Carlson.



Convert it to output on Ch. 1 and feed it to your pre-war TV.

Convert it to output on Ch. 1 and feed it to your pre-war TV.

Pretty sure neither I or the OP have a Pre-war TV. I'd like own one some day but given they tend to go for classic car money and I'd rather have a classic car for the money it will probably be a while before I own one.

I found a " Dunsel "

An old Blonder Tongue Ultraverter Dunsel to be exact!
https://www.ebay.com/itm/201511735381?ViewItem=&item=201511735381


We sold a gadzillion of those back in the day. Biggest problem with 'em was intermittency of the wipers on the tuning rings. Cleaning and re-lubing usually helped. Used a 6AF4 and 6AB4. The one tube version had just the 6AF4. Don't recall ever replacing a tube.

Pretty sure neither I or the OP have a Pre-war TV. I'd like own one some day but given they tend to go for classic car money and I'd rather have a classic car for the money it will probably be a while before I own one.

I meant to say "early post-war".

You can afford lots of Hallicrafters T54s with Ch. 1. They make good pictures:
Hint for them: buy a cheap 4" 230 volt AC fan and put it on the RF coil ...
it works nicely on 122 volts and is quiet as a whisper.

I assure you however that pre-war US TVs can be had for reasonable prices
if you are willing to settle for a TRK120. You're thinking British.

Right now, my FADA is still in direct A/V input mode, as I had trouble with doing the IF alignment procedure, tried more than once, where as the tuner DOES work, there is heavy RFI on channel 3, which is seen to a lesser degree on 4, and adding a rf amp helped even more, it did not make it go away completely, but when I did get a BT modulator for chan 7, I did find it free from RFI, but the tuner has contact problems on THAT channel :(

The instructions clearly says set to channel 9 when doing IF alignment on this set, but someone said that any chan can be used ( this is also reflected in later instructions for other sets ) , since the osc tube is removed and the signal fed in the aunt input.
For example, I just ordered a BT modulator for chan 11, if I can confirm that 11 works OK w/o any problems. Can't I use 11 in the alignment procedure where it says to use 9? will it make any difference?
https://i.imgur.com/HpMK2wJ.jpg

But then what to do with the BT mod chan 7? use it on my CTC-16XL? :p

interesting idea.
But it too has minor IF problems, that I don not have the equipment to adjust, :(
nothing really THAT bad, just red bleeding that will move with the fine tuning, perhaps I will try to fix SOME day!

But for the stromberg carlson x-21 , I do like the idea of feeding it UHF and having the ultraverter convert for it! I just have to be sure to find a modulator that IS uhf and not CATV . :p

Many moons ago, I had a Philco UHF up converter. I used it with my 1076 B&K TV Analyst which only had VHF coverage. Set the 1076 to channel 4 and hook up the Philco and you had channels 14-83 at your fingertips. When I got a 1077, I got rid of the Philco.

I particularly remember the precision vernier for setting the UHF channels. It even had a hand typewritten scale which told you the exact setting for each channel.

Many moons ago, I had a Philco UHF up converter. I used it with my 1076 B&K TV Analyst which only had VHF coverage. Set the 1076 to channel 4 and hook up the Philco and you had channels 14-83 at your fingertips. When I got a 1077, I got rid of the Philco.

I particularly remember the precision vernier for setting the UHF channels. It even had a hand typewritten scale which told you the exact setting for each channel.

So you fed the CH4 output of the B&K into the output of the UHF converter and the converter worked backwards and spit UHF out of it's input?....I never thought of that but the principal seems sound. This gives me some fascinating ideas for UHF agile modulator add-ons to my existing VHF modulators.

I will try to put the final touches into the FADA this weekend, which will involve.
Adding a power switch, as this was part of a combo unit, it never did have one. :O
Adding a A/V bypass relay circuit so I can easily switch from direct to RF input, to be powered from 6v filament voltage.
Mount the volume in a decent location with a knob.
Try again to do the IF setup, most likely on channel 11 this time, given that the BT modulator on the way is for 11, most likely just need to adjust the noise traps and 1st IF, will try antenna input first, but if that still gives problems will try direct input on point E on the tail end of the mixer, and if I STILL can't get the IF set up that way, I will just stick with direct input.

As it was mentioned before, I should not HAVE TO set to channel 9, or any specific one to do this with the osc removed...

And finally, once I have done all I can, ( I hope :P ) take it section by section to it's final location to re-assemble, for one thing that's clear about this set, you do NOT move it when all together, this is more so true now that I don't have the chassis bolted in the cabinet, I deliberately measured and cut things so that there was an about an ½ inch gap between the cabinet bottom and the chassis, I have it sitting up on the bolts for cooling.

Many moons ago, I had a Philco UHF up converter. I used it with my 1076 B&K TV Analyst which only had VHF coverage. Set the 1076 to channel 4 and hook up the Philco and you had channels 14-83 at your fingertips. When I got a 1077, I got rid of the Philco.

I particularly remember the precision vernier for setting the UHF channels. It even had a hand typewritten scale which told you the exact setting for each channel.

I believe that would be the Philco G-8000. They show up for sale now and then.

https://worldradiohistory.com/hd2/IDX-Service-&-Sales-IDX/Archive-Radio-Retailing-IDX/IDX/50s/Radio-Retailing-1953-11-OCR-Page-0021.pdf

https://www.radiomuseum.org/images/radio/philco_philadelphia/vhf_to_uhf_signal_generator_adapter_1739268.jpg

So you fed the CH4 output of the B&K into the output of the UHF converter and the converter worked backwards and spit UHF out of it's input?....I never thought of that but the principal seems sound. This gives me some fascinating ideas for UHF agile modulator add-ons to my existing VHF modulators.

I think you may be overthinking this. ;) More likely used the 1076 as a VHF signal source into the UHF converter, in order to make the 1076 signal usable on UHF tuner TV's. I can't imagine what else what would have been going on.

Yep, that was the unit I had. I liked the line in the ad which said each unit was individually calibrated. Didn't use it much, but when I did, it was really handy. The 1077 could provide the UHF signal, but not with the accuracy of the Philco G-8000.

https://imgur.com/fnI3Cvj
FADA in final location.

made last attempt to do IF adjustment, wont know if it worked until BT mot chan 11 shows up.

A/V bypass relay is installed and working

done, almost waiting for volume pot.

top view
https://imgur.com/qrTbhTb

They are NOT here... yet! :P
https://imgur.com/rGoq2pW

Well, I SHOULD HAVE had the Blonder Tongue Micm-c modulator (chan 11) today, but due to a certain nameless someone's sinister sabotage of the USPS lately, it is NOT arriving on time, like many other mailed items lately, I now have no idea when or if I will ever get it. :(

No way to know if my tweaking of the IF section worked or not yet... :tears:

who knows when it will get here now... :/

One thing I DID notice when I tried ( I saw this before, ) if I follow the setup exactly, and set the voltage gain as the want on the “contrast” to -3v, I got nothing at the testpoint, no matter what freq I put in, I had to back it away from -3, until I could see some sort of reaction to what I was feeding into the tuner, then I went and adjusted the traps only, the 1st IF coil was already tuned to the optimal setting, which I set by visual long ago.

The BT modulator for channel 11 arrived, damaged , but fixable.
it's working WELL on channel 11, no audio in the picture and looks like the IF setup worked this time, well, as well as a n00b like me could do it! :D

https://www.youtube.com/watch?v=w-t2T0c-0To&feature=youtu.be

Yes, success! Looks great.

That's not to say, that it won't benefit from more work, like a tuner rebuild, but since I never did such a thing, if I were to try, it would most likely never work after if I did. :(
something like was done here.
http://worldphaco.com/uploads/621TSARTICLE.pdf
half of the 1500 pf caps in the IF section are still original, ( same caps are used in tuner ), and all the 270 pf coupling capacitors are still original, some people said to replace, others said only to replace if they were giving problems, I did buy all new ones, but opted not to put them in, cause I did not want to face a total end to end IF alignment.

Granted, its not working at optimal condition tuning wise, but for its age, it is working very well and usable! :D:banana:

IF and video response look good. These sets could resolve the video carrier out to 4.5MHz which was better than many sets of the day and better than most 1954 and later monochrome sets (which usually rolled the IF off above 3 MHz to hide the dot crawl of the chroma subcarrier. Even if it isn't all the way out to 4.5 if it can resolve details finer than the subcarrier dots you're winning against other sets around that vintage.

The left ringing and the occasional retrace lines could probably be fixed if you want to.

IF and video response look good. These sets could resolve the video carrier out to 4.5MHz which was better than many sets of the day and better than most 1954 and later monochrome sets (which usually rolled the IF off above 3 MHz to hide the dot crawl of the chroma subcarrier. Even if it isn't all the way out to 4.5 if it can resolve details finer than the subcarrier dots you're winning against other sets around that vintage.

The left ringing and the occasional retrace lines could probably be fixed if you want to.

The left ringing is most likely due to that I have not touched the horizontal linearity adjustment yet on it, there is a barely perceptible squeeze on the extreme sides, that I have not tried to play with yet, I do have a DVD with a linearity adjustment pattern on it, but it's a nightmare to navigate and pause on to use :(
As for the retrace, I still may experiment with adding vert blanking to be able to turn up brightness w/o having it show up.

Is the point that there's no or much less interference on UHF, if you use that to transmit in the house, vs VHF?

If it is still working and you have an agile modulator transmitting at UHF you could hook it to your 630 clone or your Setchell (or was it Stromberg? :scratch2:) Carlson.

I have a few of that things cousins near my work bench. I forget if their gutted or not...I've got roughly 4-6 UHF converter and or VHF antenna amps and 1-2 or the ones I bought were gutted by their previous radio collector owners... one day I'm going either built an AM transmitter in or a clone of a vintage tube RF modulator I bought from the ETF a few years ago.

Is the point that there's no or much less interference on UHF, if you use that to transmit in the house, vs VHF?

Nope. My point was they had an antique UHF converter designed to add UHF to older sets that didn't come with UHF when new, and they could still use it if they transmitted UHF.
Interference varies from place to place depending on a number of factors. UHF could be better or worse depending on where you are, what UHF DTV channels are transmitting* in your area, what type of noise is produced by the switch mode supplies you and your neighbors are using, atmospheric noise, etc.

My advice to anyone planning to transmit their own low power analog is start with an agile (agile meaning you can change which channel it transmitts on) modulator, a DTV converter box with signal strength and manual RF channel selection in the menus, and an analog TV.
*You don't want to transmit on a channel that a local DTV station is using as you'll interfere with each other (the UHF band tends to be more packed with transmitters, but ATSC 3 is changing that). I typically use my Zenith DTV converter boxes to figure out which channels have active DTV stations and avoid those channels (I need to get an ATSC 3 capable box to check for those signals too). The static on an analog TV can tell you a bit about what noise exists on what channels too...once you have an idea where other transmitters and noise exists pick something that has the least of that, set your transmitter to one of those promising channels and try it out...If it sucks try a different channel.

IMO The fixed channel modulators are something you get after you've tried a channel with the agile modulator and know it's good... Otherwise you risk undiscovered interference making the fixed channel modulator as useful as a door stop.

As for the remaining minor annoying horz issue, mainly the slight fold-over / ringing on the left, there IS a way to adjust it, but it's nearly impossible to do in this set due to the 12 inch screen, and the location of the adjustment, RCA just did not think ahead here.

On the osc transformer, there are 2 adjustments, B2 (on SAMS) HORZ FREQ, which can be adjusted from the back, and B1 HORZ PHASE, which can only be reached from under the chassis.
https://i.imgur.com/oFR1Zab.jpg

The horz osc transformer can be seen here, the metal can at the back opposite the vert output transformer.
As this adjustment is best made with the CRT that is being used in the set, and after all other respective geometry set, ion trap, focus coil and so on, and since it depends solely on the cabinet for safe CRT support in this case, there is no way to reach that adjustment once the CRT is set in place. :(

It seems that the only option right now would be to cut away a section of the bottom of the cabinet so I could reach in and adjust it, but this will be left to a future date.

As for the nonlinearity, IE, the very slight compression on the L/R sides, not sure if that's normal or not now with the set, the horizontal linearity adjustment DID have some effect, but not much on the extreme sides, however, there are 3 caps I have not changed yet.
https://imgur.com/vrj7U91

The pair of 220pf only show up on the 12 inch FADA version, and I can only assume are there to widen the sweep, and the 56pf in the yolk, these may or may not be out of tol, and who knows what effect it may be having. :sigh:

But at this point, I deem the horizontal issue a minor nuisance at this point, not worth pulling the thing apart to deal with, will add it to the list along with the retrace mod for something to think about later. :D

Linearity adjustment is intended to affect one side of the picture with respect to the other, not both sides compared to the middle.

Depending on the sweep angle, a design may have an "S" capacitor to compress the sides because wide sweep angle tubes tend to expand them. I don't think that would be the case for this set. A slight edge compression may be normal for this set and tube.

My FADA is still working fine without problems so far, in spite of the oddly low measurement on the primary winding of the FBT, it's been run many times for hours with no release of any “magic blue smoke” or red-plating on the HOT, so I'm not sure what to make of the low reading, or if it really meant anything.
But I still have the NOS replacement on hand just in case.
The only thing I HAVE noticed with the set is that the IF section is still not optimally tuned, and given how old it is and what it has been through, AND, how hard this one is to tune in the first place, I'm not surprised, but I can tune in a decent picture and audio, and if needed, flip to direct A/V input.

One thing I am impressed with is how much audio power it can generate, the 6K6GT can easily overpower the little 5w 6x9 speaker I put in there, I now wish I got something a bit bigger!

For the ringing on the left hand side take a look at RCA application note AN-151 which is available in the archives of the Electron One website. There's a wealth of historic information stored in those archives. Anyhow, AN-151 breaks down what can be the cause of that ripple and hopefully you can narrow it down to beam current modulation or modulation of the scanning current. Here's the link to the document.

http://www.one-electron.com/Archives/RCA/RCA-AppNotes/RCA%201952%20AN-151%20Minimizing%20Ripple%20and%20Interference%20i n%20Horizontal-Deflection%20Circuits.pdf

random running of my Fada TV :)


https://www.youtube.com/watch?v=r-WCPDdn9mk

Today marks about 3 years since i completed my FADA, and it's still going strong! :banana:

http://suzaku.live-evil.org/0816231928.mp4

Nice!

OK...

:scratch2:

this is a bit weird.

This tube has ALWAYS been brighter in this TV, the 1st video amp, 6AU6, it flashes MUCH brighter when first turned on, then dims down a bit, but is always brighter than all the other tubes, but always seemed to work, an RCA branded tube. may be one of the original tubes.
http://suzaku.live-evil.org/0209241844b.jpg

Just to see what would happen, stuck in a NOS sylvania, and it warms up slow like the others, and is not as bright as the RCA that was removed, not seen a tube act like this before, almost as if they mis branded a 4AU6 as a 6AU6 :O
weird.

Connect is to 6.3V and measure the heater current. Should be 300ma. If significantly higher, something is amiss.

Connect is to 6.3V and measure the heater current. Should be 300ma. If significantly higher, something is amiss.

At 6.3v dc it's 368ma, after the large warm up spike.

Likely a couple of loops of the heater have shorted together, reducing the total heater resistance. :scratch2:

jr

Most likely, just know that it IS an RCA, could be an original from when the set was made.

Hard to see any kinds of date codes on it, not sure how to decode them anyway, :(

Looks like under the “Made in USA” 8 (or B)-71.

No idea if that's what it says or what it means.

Thankfully the planet is still littered with NOS 6AU6's :D

Thankfully the planet is still littered with NOS 6AU6's :D

correct,

Cause the video out was acting a little weird, I have some NOS tubes on the way to replace what's most likely 50+ year old ones.

Thomson France 6AU6WB Military Grade (1st video) I had other 6AU6s, but, you can't turn down mil spec!

6K6GT (2nd video-output) thank you audiophiles for making this tube cost more than it should.

6AL5 (video det/ dc restoration) the only tube not with an inflated price. :(

A weird thing about this set is, the schematic shows the HV to be at 9k, which is the nominal voltage for a 10BP4, standard CRT for the RCA 630TS of which this is a clone of.

HV tests puts output at 10k at mid brightness.
However. FADA put in a 12LP4, and specs show that to have a nominal voltage of 11k.
Did they flub things a but to put this tube in?
It does work, but I can turn up the brightness to a point that it overloads the HV and blooms.
W/O a load, the FBT is putting out about 10.2k, this seems OK for one made for 9k. :O

https://www.youtube.com/watch?v=F17FDW2efp8


bored, decided to run 3 of them today!

Odd behavior with brightness / contrast localized.
Power supply seems to be acting up a bit, it's NOT the pair of 5U4GB tubes, tried new, no change.
Have noticed slight changes in brightness / contrast as the set is in operation, could not work out the cause, then noticed that the horizontal width would change in relation to the sound when vol was up high, pulled the 6K6GT audio output to try another I had, brightness / contrast came up substantially, tube swap made no change.
Working much better with audio output removed, possible sign that the bleeder resistor network which is still original save for 1 section is starting to fail.
However, not willing to pull it apart just yet, as this chassis originally did not have audio output to start with, I'm going to use a band-aid method to keep it going till I'm ready to work on it again, at which time I'll also attempt to do a IF alignment, which it really needs.

So, in the meantime, remove the audio output and use a cheap ext class D amp.

If it's anything, it is likely to be the candohm resistor and not the huge 2 section ceramic resistor, as I remember, there was one section of the candohm that was slightly too high (r128 SAMS), and was bypassed, so prob, other parts are starting to go as well.
Of the 3 parts, one is a bit hard to match.
R 128-A(6750-ohms) 3.2watts
R 128-B(12-ohms) ½ watts
R 128-C(93-ohms) 4 watts

what I found to replace. (mouser parts)
594-AC040006801JAC00
756-WP2S-12RJA25
71-NS00593R00BE12

These should be close enough, I would hope! :)

So, the to-do list for my FADA is...

Fully replace the suspect candohm resistor with new power resistors with ones as close as I can get.
The main large one is still OK and will be left alone.

Replace the 270pf caps in the video IF that I left in there, I did get them 4 years ago, Mouser #598-CD15FD271JO3F, just did not put them in, I'm sure they are still around someplace, I hope, they have come up $1 in the last 4 years, :(

Re-check original resistors that were OK last time, any drift out of tolerance ?

Increase electrolytic capacitor in audio output area (20uf now), one of the problems seen was shrinking horizontally in relation to the audio when the sound was turned up rather high, may also add a bit more capacitance to the pi filter circuit.

Address the annoying damper heater issue, once in a blue moon when turned on the damper won't heat, and a slight wiggle gets it working again, then it's fine for weeks and weeks again, most likely a poor connection.

And lastly, alignment attempt, I CAN tune in stuff, but it is very picky, fussy, the 270pf caps will most likely help with this, but sound and video are still very hard to get matched up, as mentioned before, and I did start this with one IF coil broken off, so the fact that it is working as well that it does now is rather lucky, I just hope it's not TOO hard to align with just an rf generator.

http://suzaku.live-evil.org/0624241853.jpg

yop. I still have the caps.

But I will wait til it gets cooler before I even think about doing it!

Quick question, how critical is that sort of trapezoidal metal shield that goes under the audio section in these sets?

Right now it is off on mine, have it in a box in storage.

Annoying damper heater issue update.
Last early July after it seemed to have gotten worse, I got another NOS 5V4G, last one was new when I finished the restore, now it has not acted up since.

Now it's still a socket issue and it likes the new tube more, or the old tube was having issues. :sigh::scratch2:

I just know it has worked OK so far, dare I put the HV cover back on and go for the long run? :D

Octal sockets are fairly cheap. If it's one of those junk wafer types replacing it is a good idea.
If it's the bakelite style it's possible to repin the original...Which I've done on 5U4 sockets a few times. Basically identify which of the pin contacts are not gripping /conducting well, thoroughly desolder them pinch in the locking tang and straighten them, push up from the bottom and out the top...Do the same for the contacts that the tube doesn't have pins to plug into and use those to replace the bad ones (if you have a NOS spare of the same brand and style of socket you can take pins from it instead of you like), then install your fresh pins in the reverse order of how you removed the bad ones.

I'm gonna close up the HV case and keep an eye on it, IF it does it again, then it's indeed the socket, and needs attention, if it keeps working like it has been, then perhaps the previous 5V4G has poor solder on one of the heater pins.