View Full Version : RCA CTC...Something? poor HV output.


Arcanine
10-08-2015, 11:57 PM
I'm not sure which CTC chassis it has. Originally I wanted an RCA to begin with, and I ended up with one today. I'm selling both of my Zenith's to Jim.

It's a New Vista set, Model GF 631, if someone knows which CTC this is, that would be awesome!

The high voltage is very poor. If the probe I have is accurate at all, the set is only producing around 12kV. It does display a picture, even though the voltage is poor. Adjusting the HV Output only changes it 1kV or 2KV, not much adjustment.

I don't hear any arcing in the flyback box, and there is some melted wax, but no carbon tracking so the flyback isn't arcing out. I don't have any spare tubes for this kind of set. I'd like to know where to start before I have to suffer the pain of ordering them all on ebay.

It worked fine about a year ago, and it's just been sitting since. I have all the pictures of it. I'll post them below.

http://img.photobucket.com/albums/v480/RileyWestwolf/ssc_zpsehprkiuu.jpg (http://smg.photobucket.com/user/RileyWestwolf/media/ssc_zpsehprkiuu.jpg.html)
The pictures below show it was working a year ago and how it looked, a year ago.
http://img.photobucket.com/albums/v480/RileyWestwolf/cccc_zpslrswqyjf.jpg (http://smg.photobucket.com/user/RileyWestwolf/media/cccc_zpslrswqyjf.jpg.html)
http://img.photobucket.com/albums/v480/RileyWestwolf/cc_zps02nzdenz.jpg (http://smg.photobucket.com/user/RileyWestwolf/media/cc_zps02nzdenz.jpg.html)

Electronic M
10-09-2015, 12:04 AM
I'd have kept a Zenith and dumped the RCA.....Tubes+PCBs=more frequent harder to fix troubles....As some one who runs an RCA(clone roundy) and Zenith(hybrid rect) side by side as daily watchers and has done so for 5+ years I can tell you that the RCA construction method/circuits are more of a pain to fix (and need to be more often) when they act up.

Depending on the chassis variant I probably have most or all of the tubes in my stocks. If it is a CTC-15 set I could probably sub known good tubes from one of my sets to test it.

If you have not tried the HV reg adjustment, then you should....If that don't help, pull the top cap off the HV reg tube (may need to place in a jar to prevent arcing) and see if the HV improves....If it does the reg needs work....If not suspect the HV rectifier on back to the H osc.

StellarTV
10-09-2015, 12:07 AM
You have a CTC16 there. Any previous service information/parts replacement? If not then it's probably full of stock components.

Some might suggest a resounding "full recap!" I think that the capacitors in the RCAs of this era are actually quite reliable, but unless you're able to solve the low HV issue by swapping out the Horizontal Output, Damper, HV Regulator and Rectifier tubes then you're going to have to get a print and start checking voltages.

Arcanine
10-09-2015, 12:20 AM
You have a CTC16 there. Any previous service information/parts replacement? If not then it's probably full of stock components.

Some might suggest a resounding "full recap!" I think that the capacitors in the RCAs of this era are actually quite reliable, but unless you're able to solve the low HV issue by swapping out the Horizontal Output, Damper, HV Regulator and Rectifier tubes then you're going to have to get a print and start checking voltages.

No idea. I was told the CRT is much newer, and it looks it by how it was working. It's an RCA "Hi-Lite", it has a few GE Compactrons throughout the set, all the HV tubes are still RCA lables, thus I presume original. I can get a stable, blurry picture out of it, so the horizontal output is working.

I have 4 Dentron 6LQ6 tubes that are still strong, the HF amplifier they lived in was still doing good strong power when I used it. I swapped one in, and the HV won't even kick in on these. It has an RCA 6LQ6 in it as is, and it's working fine.

StellarTV
10-09-2015, 12:31 AM
That is bizarre. A weak Horizontal Output can cause HV issues, but you'll usually get a picture that won't fill out horizontally. I think it's safe to say your stock HO tube is doing it's job, but those other tubes you have should light up and run too.

And that CRT looks amazing too. You got a good one!

Are you running at full brightness? Will the picture "bloom" (defocus and expand) when the brightness control is fully advanced?

rca2000
10-09-2015, 12:37 AM
I can see NO WAY....you ONLY have 12KV here. The pix is WAY too good--and full. 12 KV would NOT give a full raster--and focus woulod likely be VERY bad..


YOU DEFINITELY need to check your HV PROBE !! I'll BET...from that pix...you are getting at LEAST 23KV.

Arcanine
10-09-2015, 01:06 AM
I can see NO WAY....you ONLY have 12KV here. The pix is WAY too good--and full. 12 KV would NOT give a full raster--and focus woulod likely be VERY bad..


YOU DEFINITELY need to check your HV PROBE !! I'll BET...from that pix...you are getting at LEAST 23KV.

I'm sorry. I did not mean to incite confusion.

The pictures posted first are of the set before the previous owner stored it. It does NOT display like this today. That is how it was. and should be...

http://img.photobucket.com/albums/v480/RileyWestwolf/image_zpsuqykawcm.jpeg (http://smg.photobucket.com/user/RileyWestwolf/media/image_zpsuqykawcm.jpeg.html)

That is what I see on it, today. After about 15 minutes of on time, focus goes, then the picture fades out.

old_coot88
10-09-2015, 02:18 AM
Take a look at the two 6GU7s on the far right end of the chroma board. Are their heaters lighting?

If not, with those heaters cold, here's what's happening: the plates go 'waay positive and drive the (G1) grids of the CRT positive (since the plates are direct-coupled to the CRT grids). The CRT beam current goes into avalanche, producing exactly the symptoms you describe. And this overcurrent is extremely hard on the 3A3, flyback, and H.output tube.
Don't run the set in that condition.

Of course if the 6GU7 heaters are lighting, then the problem lies elsewhere.

If the heaters are cold, it's caused by a broken ground in one of the two ground stakes on the far right end of the chroma board. So re-flow those grounds. This problem was endemic to the CTC-12, 15, 16, 17, and 25.
Even if the 6GU7s are lighting, re-flow those grounds anyway as a matter of routine.

bluenorm
10-09-2015, 11:21 AM
I have the same set (ct16) and in my case the first symptom was the lost of converging adjustments in one of the color(green) hv was check and was detected at 17 thousand top, a few days later was at 15 and the poof. chassis was removed and all the voltages coming out of electrolytic tested ok. the high voltage transformer burned. it was replaced with a nos and all problems were solved.

bluenorm
10-09-2015, 11:37 AM
what old coot88 describes happen to a friend of my ct15's or 16, exactly as he stated. he discovered by pressing down the 6gu7 and later pressing the board near the ground stakes thus making ground. an easy fix.

DavGoodlin
10-09-2015, 12:39 PM
To add to Old Coots' post: there are two brown wires that run on TOP of the PCB between the 6GU7s and the 6GY6s. These carry filament voltage to 6GU7/6GY6 on right side, and due to heat, corrode to green dust where they enter the PCB hole.

Arcanine
10-09-2015, 01:11 PM
To add to Old Coots' post: there are two brown wires that run on TOP of the PCB between the 6GU7s and the 6GY6s. These carry filament voltage to 6GU7/6GY6 on right side, and due to heat, corrode to green dust where they enter the PCB hole.

Both of my 6GU7's heaters light up, and it appears the aforementioned connection has seen a reflow already. I tried wiggling them around a little, and nothing changes at all.

I also noticed there is a fair amount of arcing out of the top of plastic cup on top of the fly back box. The wire to anode goes in though there, as well as two others. I'm going to need to see what that's about. I'm sure that'll be worse once I get the HV back up.

The tubes are largely original, almost all RCA. I'm hoping I just have a flat tube. I'll add the 6GU7's to the check list.

Arcanine
10-09-2015, 01:18 PM
http://img.photobucket.com/albums/v480/RileyWestwolf/fdfd_zpszna6dy5q.jpg (http://smg.photobucket.com/user/RileyWestwolf/media/fdfd_zpszna6dy5q.jpg.html)

Something tells me this tube shouldn't be so... crispy...and dark. The camera can't even pick up on just how bad it actually is looks.

This is the 6EL4 tube. It's also RCA original.

DaveWM
10-09-2015, 01:48 PM
tube dark from xrays, just means had a lot of use, does not mean bad.

you should 1st try running the set with the CRT plug (the base socket)disconnected, this removes the load of a CRT which may be high due to bad CRT or incorrect bias.
Check HV

if no change, then try disconnect the 6Bk4, this takes the shunt tube out of the circuit, could be a prob if bad or bias is wrong.
check HV

if still no change
Check Horz out voltages, screen and grid
Check Horz out cathode current
Report back findings for whats next.

Arcanine
10-09-2015, 02:06 PM
tube dark from xrays, just means had a lot of use, does not mean bad.

you should 1st try running the set with the CRT plug (the base socket)disconnected, this removes the load of a CRT which may be high due to bad CRT or incorrect bias.
Check HV

if no change, then try disconnect the 6Bk4, this takes the shunt tube out of the circuit, could be a prob if bad or bias is wrong.
check HV

if still no change
Check Horz out voltages, screen and grid
Check Horz out cathode current
Report back findings for whats next.

CRT plug disconnected: 14kv

6BK4 Disconnected CRT plugged in: 14Kv

I'll have to check the other two after my trip to see Jim.

I made sure I had a stonger connection with the probe today, the set is managing 14Kv

StellarTV
10-09-2015, 06:16 PM
http://img.photobucket.com/albums/v480/RileyWestwolf/fdfd_zpszna6dy5q.jpg (http://smg.photobucket.com/user/RileyWestwolf/media/fdfd_zpszna6dy5q.jpg.html)

Something tells me this tube shouldn't be so... crispy...and dark. The camera can't even pick up on just how bad it actually is looks.

This is the 6EL4 tube. It's also RCA original.

HV Regulator tubes use lead-impregnated glass to minimize X-ray emission. They darken with use.

Username1
10-09-2015, 06:16 PM
I think people have posted before that the version B & C of those tubes are darkened
with a coating to help contain some of the x-rays they can produce.

With 14KV and the reg tube removed, that means its caused somewhere else. Be sure
the HV rectifier is good. Then check for the Possibility of problems in the horiz output
drive, or in the flyback. With good width is may be in the flyback.
A good place to start is the voltages around the H output tube. Also be sure to check that
the flyback is not getting too hot while on, check bias voltage on H output, and cathode
current.... I think a number of people here have been on that street before.....

.

DaveWM
10-09-2015, 07:20 PM
oh yea forgot the HV rectifier.

with poor HV (with CRT unplugged) the SOP is to replace the Horz out,Damper,shunt and HV rectifier with KNOWN good tubes. You cant go by tube testers.

if those four make no difference the check the Horz out tube pin voltages.

This assume of course you have checked the B+ to know the power supply is ok.

DaveWM
10-09-2015, 07:27 PM
there is one item worth mentioning, beginning I think on the CTC-15 there was an additional HV hold down circuit added. It works by take the rectified neg voltage from the blanker tube and feeding it back to the grid of the horz out thru a voltage divider. The Idea was if the HV shot up too high this hold down (the blanker got its voltage from the fly) voltage would bias the grid of the horz out more neg, cutting off the tube.

You can tell this when the grid of the horz out is TOO neg. esp if you have a scope and the wave form of the drive signal is normal (compared the neg reading at the grid).

what happens is the voltage divider (390k again IIRC) resistor on the chroma board loses its ground thru a very thin trace that runs right along the side of the board right by the HO tube. the trace cracks, the voltage divider no longer divides, and voila you get TOO much hold down. a simple test is to use the resistance charts for the blanker tube. if the grid resistance is too high its prob the crack in the board.

Arcanine
10-09-2015, 10:19 PM
Okay. I got things to check then. I'll report back on my findings as I go along. I am out of town for the weekend so I will report back when I start to poke at this set again.

I'm really really hoping the flyback it self isn't bad.

Arcanine
10-12-2015, 11:10 PM
The part I'm not understanding is; The picture is very bright, and I can turn the brightness up all the way and the screen doesn't bloom or go out of focus. In fact the focus is quite good.

When I play with the controls on the front, or change the channel, vertical conks out for a second or two before it pops back in. It struggles to hold vertical control as well. And while bright, the picture does remain quite yellow.

I wonder if my HV probe is just junk? Perhaps the problems are in the vertical section? Horizontal width is still good. And I can get a very sound horizontal lock.

I've swapped the tubes around a couple times with good ones, and still no improvements.

Arcanine
10-13-2015, 03:44 PM
Would a stone cold dead 1v2 focus rectifier cause the issues the set is suffering from?

I tried to test it today, nothing glows inside, and it is fully dead according to the tester. I can't get anything out of it.

Arcanine
10-13-2015, 04:33 PM
It actually had a 2AV2 in the socket. I still can get nothing from it on the tester with the correct filament voltage. It at least glows but does nothing.

I can get the needle to show something with the 3A3 and the other high voltage rectifiers, but this one shows nothing. Not even a little twitch.

I also don't think the socket has been modified at all to make a 2AV2 work.

zeno
10-13-2015, 04:37 PM
1) bad focus rectifier gives bad focus !
2) your pix bright, full width, does not bloom.
The hoz osc, out, damper, rectifier, focus rectifier, HV reg
are all good. Your meter is NG, try it on another set.
3) arcing at the HV rect socket usually the cup. Other 2
wires are the filament & wrap around the FBT core.
ALL the wires are at full HV potential. & can arc anywheres.
4) Try a "by the book" grey scale set-up. then turn you attn
to the 6GU7 area of the set. Watch for dried up wires, they
were common even 45 yrs ago.
5) put up a few screen shots that show people & colorful scenes.
A pattern is fine but a real scene shows more.
6) the old pixs looked AWESOME so unless the jug has aged
fast & it happens, you will have a great set.
7) so you have 3 problems. Vert, arc & poor color. You should
get a first generation Sams for this set.

73 Zeno:smoke:

Arcanine
10-13-2015, 05:01 PM
1) bad focus rectifier gives bad focus !
2) your pix bright, full width, does not bloom.
The hoz osc, out, damper, rectifier, focus rectifier, HV reg
are all good. Your meter is NG, try it on another set.
3) arcing at the HV rect socket usually the cup. Other 2
wires are the filament & wrap around the FBT core.
ALL the wires are at full HV potential. & can arc anywheres.
4) Try a "by the book" grey scale set-up. then turn you attn
to the 6GU7 area of the set. Watch for dried up wires, they
were common even 45 yrs ago.
5) put up a few screen shots that show people & colorful scenes.
A pattern is fine but a real scene shows more.
6) the old pixs looked AWESOME so unless the jug has aged
fast & it happens, you will have a great set.
7) so you have 3 problems. Vert, arc & poor color. You should
get a first generation Sams for this set.

73 Zeno:smoke:

The focus does suck. So I ordered a NOS correct RCA 1v2 to replace the 2AV2, so it's a place to start. I'll look at the wires next and replace as needed.

Then I will set it on fire, and throw it off a bridge.

TUD1
10-13-2015, 06:22 PM
Don't set it on fire and throw it off a bridge. I can PROMISE you it won't fix the problem.

Username1
10-13-2015, 06:44 PM
When you set it on fire and make it go off a bridge, do it in a cool way ! Put wheels on
it, pull it with a rope, make it crash into another set, set an explosion at impact, then
have the console go up a ramp, hidden by the smaller tv, explode at the top of the ramp,
spin in the air once or twice hit the ground & slide then go off the end of a bridge, crash
on the shore next to the water, and then explode again ! That would be Hollywood Cool ! !

Yah....... Oh, don't forget to film it from several directions, splice it into a really good
reel, and put it on youtube ! !

Yah......

And post a link to it too..... ! !

.

TUD1
10-13-2015, 06:55 PM
Or just give it to me. I'll go buy you a BPC set if you want to throw something off a bridge and whatnot.

Username1
10-13-2015, 07:57 PM
Explode it and crash it off a bridge ! Don't tell TUD1 till it's over.....SShhhhhh......


.

Electronic M
10-13-2015, 08:28 PM
Explode it and crash it off a bridge ! Don't tell TUD1 till it's over.....SShhhhhh......


.
:lmao:

A bad focus rect. tube will cause bad focus. One thing you could do while you wait is go to Radio Snack (if one still exists near you) and get 4 of the 1.5KV diodes they sell, and string those in series as a SS focus rect......IIRC roundy focus voltage is ~4100V so 6KV worth of diodes should be able to take it....Maybe add a 5th or 6th for good measure.

Arcanine
10-13-2015, 08:46 PM
:lmao:

A bad focus rect. tube will cause bad focus. One thing you could do while you wait is go to Radio Snack (if one still exists near you) and get 4 of the 1.5KV diodes they sell, and string those in series as a SS focus rect......IIRC roundy focus voltage is ~4100V so 6KV worth of diodes should be able to take it....Maybe add a 5th or 6th for good measure.

You got my DM last night? Lemme know what you might want. I might just commission you to fix the damn thing... I don't have the polethrea of parts you do.

Arcanine
10-16-2015, 12:33 AM
For lack of anything else to do, I poked around with the set for about a half hour. I cleaned the high voltage wires to check where they were arcing from.

And I let the set run for about 15 minutes, while I checked and watched a few things.

Nothing changed so I shut it down, checked the caps, nothing was hot, everything was cool to the touch until I checked in the flyback box...

The flyback is getting extremely hot. So much so, that I could see fresh wax dripping out of the bottom of it.

I presume that means it's shot? Internally shorted or something like that?

On a positive note: I emailed the guy I bought it from, and explained my situation, and he's giving me a complete CTC16 almost identical to this one with a bad CRT. I'm going to lay claim to the flyback for my set, but I will likely part the rest out for other's who need RCA parts.

Electronic M
10-16-2015, 03:35 AM
Have you used the H lin./H eff. coil to dip the cathode current? That is an essential procedure on RCA sets......If the adjustment is far enough out of whack the H out tube could be drawing enough current to badly overheat the fly....And RCA ran their flys hard, usually close to the point overheating.

timmy
10-16-2015, 08:03 AM
yup could be H eff coil if not checked it could be standing at 250ma right now and that would be a real cooker for the fly. and i noticed that whenever a hot tube is swapped the ma changes a bit and should be checked whenever anything is done in and around the horiz section. i have a 66 silvertone that i recapped and played flawless only problem was it would drip wax and the fly would get really hot and still played fine with the eff coil at 190ma so having a nos fly i replaced it and it never got hot again. it was only a matter of time that the fly was going to take a dump. it seemed to me that the secondary, the donut, was shorted somewhere enough to heat it up to the point of melting the wax but not affecting the operation of the set. i would check the eff current and associated components around the horiz and if all is good, change the fly, well saying that is easier said then done being these flys are hard to find.

Username1
10-16-2015, 09:23 AM
True, You might just want to set it on fire and throw it off a bridge ! !

:)

.

timmy
10-16-2015, 11:19 AM
Well no all that has to be done is leave the fly in and it will do it itself.

Arcanine
10-16-2015, 03:40 PM
http://www.boxcarcabin.com/rcacathode.htm

Is this an effective method of checking the cathode current? I did some research on how to check this, since it's important, and I may as well know how to do it.

I plan to check this later after I make my trip to Milwaukee to get the parts CTC16.

Electronic M
10-16-2015, 04:37 PM
That is a good procedure (sam's excerpt I believe). I generally do the HV adjustment after the fact. If I've adjusted the osc. that way once, and it has not failed or significantly drifted since I skip that part, and only do the cathode current.

I prefer an analog meter (I just use a Radio Snack cheapie) for this as it allows a more precise dip to be achieved. If it don't want to dip below 220mA something is probably wrong. 185-215mA is where you want to be to baby that hard to get fly.

Username1
10-16-2015, 06:34 PM
That boxcar guy has a lotta cool stuff if you fish around there.....

.

Electronic M
10-16-2015, 06:52 PM
That boxcar guy has a lotta cool stuff if you fish around there.....

.

He is a member here....IIRC his handle is CTC17.

timmy
10-16-2015, 07:03 PM
Ctc17 has been gone for awhile now.

Findm-Keepm
10-17-2015, 10:17 AM
http://www.boxcarcabin.com/rcacathode.htm

Is this an effective method of checking the cathode current? I did some research on how to check this, since it's important, and I may as well know how to do it.

I plan to check this later after I make my trip to Milwaukee to get the parts CTC16.

Easiest is using a socket adapter for the 6JE6/6LQ6 and a 300-500mA analog meter. I have a center zero one, so hooking up requires no polarity. The adapter is a Pomona 2599, and breaks the cathode circuit for you-available on eBay and other vendors.

Make sure you have a spare horiz efficiency coil - mine was seized, so i swapped coils before I started. 112875 is the part number.

old_coot88
10-17-2015, 12:05 PM
I prefer an analog meter (I just use a Radio Snack cheapie) for this as it allows a more precise dip to be achieved. If it don't want to dip below 220mA something is probably wrong. 185-215mA is where you want to be to baby that hard to get fly.
Yes, an analog meter is imperative since digital meters are prone to going nuts on complex waveforms. We just used a Simpson 260 and a Pomona adapter for the cathode current.
Since we were an RCA dealer and the first imperative was keeping the damn sets working thru their warranty period, we put the power xfmr. primary tap for 'high' line voltage, and the H.out cathode current as low as possible, 200-205 ma. max.
210 ma. would have been the absolute upper limit for any degree of longevity.

Arcanine
10-21-2015, 08:27 PM
I'm starting to think my HV probe is lying to me.

http://img.photobucket.com/albums/v480/RileyWestwolf/color_zpsezoxqoyg.jpg (http://smg.photobucket.com/user/RileyWestwolf/media/color_zpsezoxqoyg.jpg.html)

I swapped a couple tubes tonight with the CTC20 just to see, and I swapped in my NOS 1V2 focus rectifier and this is what I saw when I went around to the front of the set. A little tweak to the focus adjustment, the picture is razor sharp, my camera won't even catch how sharp it actually is.

This is the first time it's ever given me a color image.

It's also very bright and clear. I let let it run for 10 minutes on the dot and shut it off, and checked the fly, and it wasn't even warm.

I'm starting to think it's not the fly and more dead caps. It refuses to fill the screen vertically, and when no color is present, the image still looks yellowish. As soon as color pops, it looks good. It has full horizontal and locks on with out much fuss.

rca2000
10-21-2015, 08:38 PM
I TOLD you...you were NOT that low on HV...now I am SURE of it !! That pix looks like at LEAST 24KV to me--maybe MORE.

Was one of the tubes you changed the H-osc tube or damper? A weak osc tube WILL allow way too much current through the fly, lower HV and overheating. As others have said--you DO need to check the H-drive current level now--to make SURE it is under 220 MA. Cool fly tire and core or NOT...you NEED to KNOW.

Arcanine
10-21-2015, 09:11 PM
I TOLD you...you were NOT that low on HV...now I am SURE of it !! That pix looks like at LEAST 24KV to me--maybe MORE.

Was one of the tubes you changed the H-osc tube or damper? A weak osc tube WILL allow way too much current through the fly, lower HV and overheating. As others have said--you DO need to check the H-drive current level now--to make SURE it is under 220 MA. Cool fly tire and core or NOT...you NEED to KNOW.

Yes. I had one Damper crap out on me, so I've switched it. Same thing for the H-Osc tube. I swapped it as well.

I'm going to tug the chassis out tomorrow and add in the two needed wires and the cap so I can check the current. I want to make sure it's below 220 so I can baby this fly. I ran the set again for a few minutes, and it's stable and very bright.

I'm gonna get together with Electronic M soon hopefully, and I think we can hammer out the last of the sets issues and make it work fully again.

Electronic M
10-21-2015, 09:15 PM
That is not far off from how it should be running.

One thing that may be worth wile when doing the current check is to add a 1/4 amp fuse to the cathode....It will lend some protection and if you (or I) mount the fuse holder above chassis it will facilitate future current checks and adjustment (just pull the fuse and connect the meter).

Arcanine
10-21-2015, 09:22 PM
That is not far off from how it should be running.

One thing that may be worth wile when doing the current check is to add a 1/4 amp fuse to the cathode....It will lend some protection and if you (or I) mount the fuse holder above chassis it will facilitate future current checks and adjustment (just pull the fuse and connect the meter).

I like this idea. I may have you do that so it can be checked. I'm happy this set is showing it still wants to work, I was really bummed out when I first got it home and found it not really functional.

WISCOJIM
10-21-2015, 11:55 PM
Teamwork. I like that!

Only 2-1/2 weeks to the next WARCI swap. See you guys then.

.

Arcanine
10-22-2015, 04:09 AM
It may have been suffering low HV before, but no longer. The new focus rectifier, and the shuffling of tubes... And I also cleaned up some dust build up inside the HV cup on top of the flyback box since there was some arcing in there, and I also changed out the anode lead to the CRT with a 50kV rated wire from an old computer monitor, which took care of all the arcing, and makes a nice connection to the CRT, as well.

(and a minor adjustment to my meter so the needle would stop sticking)

http://img.photobucket.com/albums/v480/RileyWestwolf/HV_zpshgtbhrov.jpg (http://smg.photobucket.com/user/RileyWestwolf/media/HV_zpshgtbhrov.jpg.html)

25kV! Now, the Hi-Volt adjust is cranked open all the way, so that could be something else, time will tell once it gets more issues, and caps changed.

Now for everything else. One step at a time. This was a big step for me, very excited to see color, 25kV on the meter, and a bright stable image. This will be a nice set again soon!

timmy
10-25-2015, 07:17 PM
Could be the 1.5 meg resistors around the hv pot, may have drifted.

Findm-Keepm
10-25-2015, 10:17 PM
It may have been suffering low HV before, but no longer. The new focus rectifier, and the shuffling of tubes... And I also cleaned up some dust build up inside the HV cup on top of the flyback box since there was some arcing in there, and I also changed out the anode lead to the CRT with a 50kV rated wire from an old computer monitor, which took care of all the arcing, and makes a nice connection to the CRT, as well.

(and a minor adjustment to my meter so the needle would stop sticking)

http://img.photobucket.com/albums/v480/RileyWestwolf/HV_zpshgtbhrov.jpg (http://smg.photobucket.com/user/RileyWestwolf/media/HV_zpshgtbhrov.jpg.html)

25kV! Now, the Hi-Volt adjust is cranked open all the way, so that could be something else, time will tell once it gets more issues, and caps changed.

Now for everything else. One step at a time. This was a big step for me, very excited to see color, 25kV on the meter, and a bright stable image. This will be a nice set again soon!

Be careful with the HV and a bad/low output focus rectifier. Folks see low HV, crank up the HV, and then have out of focus pix, so they replace the focus rectifier tube or diode, and now they have too much HV, and too much focus current - it smokes the focus coil on these old sets (happened to my CTC16) - it's a no wonder the focus coils were QT parts.

Electronic M
10-28-2015, 11:53 PM
I'm overhauling it for Arcanine. So rather than fill my PM box and keep it hidden, here is a public status update.

I started work on it today. As gotten screen shots: http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0821_zpsxozgoedj.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0821_zpsxozgoedj.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0824_zpswwycoege.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0824_zpswwycoege.jpg.html)

As can be seen the grayscale was very yellow. I also had to tweak the chroma osc. to get the color bars shot.

I could not get setup lines with the service switch and had to resort to playing with the brightness and CRT bias switch to get them.....The blue was still VERY weak with it's control maxed (had to douse the lights to balance the lines with the G2 knobs)....I'm probably going to test the gun biases later to see if something is messing with the blue.

That got me here:http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0825_zpsuwq2d34w.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0825_zpsuwq2d34w.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0826_zpsdgyls7pd.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0826_zpsdgyls7pd.jpg.html)

I decided to verify HV level on my probe. With the set running on 117VAC it's producing 23.5KV, which is within the 22-24KV listed in the sam's.

I removed the chassis and decided to look at the ruined power switch. The shaft of the vol pot/power switch on the donor CTC-20 chassis was 1/2" too short, and the switch was different so that was eliminated as an option.
Opening the original switch revealed that a piece of black phenolic (SP?) that connects the switch contacts to the shaft broke. Attempt to duplicate it failed due to limited tools and lack of knowledge of the shape of the damaged part.
I then remembered I had some spare pots with similar switch shells. None of my spare pots had the right shaft length so I tried to transplant the switch section alone. One had different guts that I ruined trying to adapt to the original. The second was identical to the original switch section and I was able to mount it successfully. It works well, and no one would ever think it was a replacement. The white piece on the original shaft in the picture is what the broken black piece in the original switch should have looked like.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0832_zpsajrejtcv.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0832_zpsajrejtcv.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0833_zpsouwzyqzq.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0833_zpsouwzyqzq.jpg.html)

Now that the grayscale is right and the power switch works again, it is on to other work.....Like changing original caps of types I do not trust, going over the vertical circuit, and some adjustments, etc.

Findm-Keepm
10-29-2015, 12:07 AM
Looking good! What's the HOT cathode current running?

Always replace the cap attached to the cathode of the 'GF7 - that cap, more than any will cause problems with the vertical. Also go over the ground eyelets on the boards. Vertical / horizontal sync problems are generally caused by resistors way out of tolerance. I've restored three CTC16 sets, and outside of electros, the cathode cap, the sync resistors, and a thermistor or two, I've never replaced a single film cap.

Also clean the pins on the IF tubes - video will suffer If problems there.

Like I said, looking real good!!

Arcanine
10-29-2015, 12:34 AM
Oh wow. Those colors are really good. You really managed to get rid of that yellow it was suffering.

Excited to see the progress. This was just one of those things, I was so let down when I got it home and it almost was completely dead, I was so disappointed I didn't find my self wanting to work on it.

I got it as far as proper HV, and color on the screen then passed it on to you.

When we tested my CRT, didn't it show all the guns were pretty good? Seems strange blue doesn't want to play nice.

Electronic M
10-29-2015, 01:16 AM
Oh wow. Those colors are really good. You really managed to get rid of that yellow it was suffering.

Excited to see the progress. This was just one of those things, I was so let down when I got it home and it almost was completely dead, I was so disappointed I didn't find my self wanting to work on it.

I got it as far as proper HV, and color on the screen then passed it on to you.

When we tested my CRT, didn't it show all the guns were pretty good? Seems strange blue doesn't want to play nice.

IIRC it was blue that failed the color tracking test. This could be a side effect of that, or something else could be off in the gun bias circuits.

Arcanine
10-29-2015, 01:30 AM
IIRC it was blue that failed the color tracking test. This could be a side effect of that, or something else could be off in the gun bias circuits.

It may wake up. I have no idea how many years that TV was sleeping and how long that CRT went unused. It seems like it has a hell of a picture.

Electronic M
10-30-2015, 02:44 AM
Red eye status update.

I've found why the screens were funky. The 1020V boost was 200-300V low. The 100K resistor between the rectifier and it's loads was 2.5X rated value. Replacing it got it half way back to spec. Replacing the boost diode with 2 1.5KV PIV rated silicon ones (1 probably would have been enough, but there is no kill like overkill :D ) in series brought it within 35V of spec.....I'll call that close enough of a tolerance for my taste. Now I can back the CRT bias switch off a click and still get a bright blue set up line. :thmbsp:
http://i1095.photobucket.com/albums/i469/ElectronicMemory/th_DSCN0835_zpsai0hshj9.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/DSCN0835_zpsai0hshj9.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/th_DSCN0836_zps3dhyybdp.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/DSCN0836_zps3dhyybdp.jpg.html)

I replaced the three tubular ceramic Elmenco caps with modern parts (I've seen enough bad not to trust them). The .01 400 red tubular plastic H osc. cap next to the coil also has been replaced as a precaution.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/th_DSCN0834_zpslwp20r0g.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/DSCN0834_zpslwp20r0g.jpg.html)

The grounds on the video and sweep boards got a 150W iron touch up, and I also reflowed the some of chroma osc. traces (she has not lost color synch since last time).

I added the HOT cathode fuse holder, but I don't have any fuses down near the 1/4A range so it is a place holder until you pop one in. Cathode current dipped at about 200-205mA which seems decent.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/th_DSCN0837_zps6uou2fvu.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/DSCN0837_zps6uou2fvu.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/th_DSCN0838_zpsai0lpw1v.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/DSCN0838_zpsai0lpw1v.jpg.html)

I checked every resistor in the vertical section under the 2Meg max of my DMM and all were within rated tolerance. The V Out cathode cap was re-replaced with a new 47uF 160V replacement that is closer to the original 50u 150V cap that Arcanine replaced with a 100u 400V. The 80uF 450V off the vertical output Xfmr tested fine and B+ to it looks good. Hoping the Boost fix would bring it back I powered it up with no change in vert.

Some tube rolling got me this: http://i1095.photobucket.com/albums/i469/ElectronicMemory/th_DSCN0839_zpszixhgprk.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/DSCN0839_zpszixhgprk.jpg.html)

I think my plan of attack is going to be lift one leg of the high resistors in the vertical so my chinese component tester (which has a higher resistance range, but is more interested in the caps in the circuit) can focus on the resistors and if that fails to find fault start testing/changing the vertical stage drop caps.

Unfortunately while going thru the spare tubes (to find another vertical tube) one of the H outs Arcanine left with me managed to roll off the table and bust it's self on the floor. :sigh: I'm sorry dude, I should have been more careful.

kvflyer
10-30-2015, 07:54 AM
Red eye status update.
...
Unfortunately while going thru the spare tubes (to find another vertical tube) one of the H outs Arcanine left with me managed to roll off the table and bust it's self on the floor. :sigh: I'm sorry dude, I should have been more careful.

Looking good!

As for the tube rolling off of the counter, well, I have been not only in that church but also in the same pew as well. Usually with something like a sweep tube, audio output tube (not 50C5, think ... 7027A etc.) or Telefunken 12AX7/ECC83. Yes, very frustrating and especially when we try so hard to not have it happen!

Again, looking great!

Arcanine
10-30-2015, 12:59 PM
Red eye status update.

I've found why the screens were funky. The 1020V boost was 200-300V low. The 100K resistor between the rectifier and it's loads was 2.5X rated value. Replacing it got it half way back to spec. Replacing the boost diode with 2 1.5KV PIV rated silicon ones (1 probably would have been enough, but there is no kill like overkill :D ) in series brought it within 35V of spec.....I'll call that close enough of a tolerance for my taste. Now I can back the CRT bias switch off a click and still get a bright blue set up line. :thmbsp:
http://i1095.photobucket.com/albums/i469/ElectronicMemory/th_DSCN0835_zpsai0hshj9.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/DSCN0835_zpsai0hshj9.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/th_DSCN0836_zps3dhyybdp.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/DSCN0836_zps3dhyybdp.jpg.html)

I replaced the three tubular ceramic Elmenco caps with modern parts (I've seen enough bad not to trust them). The .01 400 red tubular plastic H osc. cap next to the coil also has been replaced as a precaution.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/th_DSCN0834_zpslwp20r0g.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/DSCN0834_zpslwp20r0g.jpg.html)

The grounds on the video and sweep boards got a 150W iron touch up, and I also reflowed the some of chroma osc. traces (she has not lost color synch since last time).

I added the HOT cathode fuse holder, but I don't have any fuses down near the 1/4A range so it is a place holder until you pop one in. Cathode current dipped at about 200-205mA which seems decent.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/th_DSCN0837_zps6uou2fvu.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/DSCN0837_zps6uou2fvu.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/th_DSCN0838_zpsai0lpw1v.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/DSCN0838_zpsai0lpw1v.jpg.html)

I checked every resistor in the vertical section under the 2Meg max of my DMM and all were within rated tolerance. The V Out cathode cap was re-replaced with a new 47uF 160V replacement that is closer to the original 50u 150V cap that Arcanine replaced with a 100u 400V. The 80uF 450V off the vertical output Xfmr tested fine and B+ to it looks good. Hoping the Boost fix would bring it back I powered it up with no change in vert.

Some tube rolling got me this: http://i1095.photobucket.com/albums/i469/ElectronicMemory/th_DSCN0839_zpszixhgprk.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/DSCN0839_zpszixhgprk.jpg.html)

I think my plan of attack is going to be lift one leg of the high resistors in the vertical so my chinese component tester (which has a higher resistance range, but is more interested in the caps in the circuit) can focus on the resistors and if that fails to find fault start testing/changing the vertical stage drop caps.

Unfortunately while going thru the spare tubes (to find another vertical tube) one of the H outs Arcanine left with me managed to roll off the table and bust it's self on the floor. :sigh: I'm sorry dude, I should have been more careful.

Wow it's really coming back to life. I'm glad I handed it off to you, it was indeed a little beyond me.

And which tube was it? Was it the tall RCA 6JE6? Or was it a Sylvania 6LQ6? If it was the Sylvania don't lose any sleep over it. If it was the RCA, well, better start sweating!

Haha nah don't worry I'm kidding, accidents happen. I have a couple more of those here.

old_coot88
10-30-2015, 01:27 PM
Since that boost diode's been replaced with silicons, be sure to monitor it (them) for overheating.
The original part being selenium, it could handle the fast retrace ("fly-back") spike whereas silicons lagged in fast-switching ability.

It might be worth asking somebody like Mouser or Digikey if they've got Schottky diodes in high enuff voltage rating. Or you could series 'em.

Electronic M
10-30-2015, 02:35 PM
Since that boost diode's been replaced with silicons, be sure to monitor it (them) for overheating.
The original part being selenium, it could handle the fast retrace ("fly-back") spike whereas silicons lagged in fast-switching ability.

It might be worth asking somebody like Mouser or Digikey if they've got Schottky diodes in high enuff voltage rating. Or you could series 'em.

Honestly, my Silvertone CTC-15 clone had to have it's Boost rect changed 5 years ago....Back then I used the same diodes to replace it, and those have been in weekly to daily use ever since without issue.....If they fail in the first 2 years of service I will be shocked.

Findm-Keepm
10-30-2015, 09:11 PM
We always used an RGP15-20 for any scan derived power supplies. It's a fast recovery 2000V 1.5A diode, and works perfectly in my CTC16, and cheap at a quarter for one diode, far cheaper than the NTE506.

http://www.fagorelectronica.com/images/download/semiconductor/rgp1520.pdf

RCA specified this type in the later chassis(M134, CTC203) and once we figured out the root part number, we ordered a bunch and never looked back. great for boost diodes, and convergence diodes.

Conventional diodes like the 1N4007 and 1N5408 are just too slow, and tend to overheat.

Electronic M
11-02-2015, 10:20 PM
Quick progress. The only vertical stage resistor under 2M I did not check (excluding controls which I skipped last session) was near the controls, and it was wide open....R102 150K .....I replaced it with another one on the top end of it's tolerance (t'was all I could find ATM).
http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0843_zpsbuismri5.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0843_zpsbuismri5.jpg.html)
Replacing it got me this.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0845_zpsp9k0ouku.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0845_zpsp9k0ouku.jpg.html)

I can't get linearity quite right though.....If I do the bottom (and sometimes top) is under-scanned, and centering is maxed downwards.....It's progress though.

This is the HO tube that died. I can't find any ID marks on it.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0841_zpsiluptwfp.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0841_zpsiluptwfp.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0840_zpsk09bppp8.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0840_zpsk09bppp8.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0842_zpsqgojqsvf.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0842_zpsqgojqsvf.jpg.html)

Arcanine
11-02-2015, 11:52 PM
Quick progress. The only vertical stage resistor under 2M I did not check (excluding controls which I skipped last session) was near the controls, and it was wide open....R102 150K .....I replaced it with another one on the top end of it's tolerance (t'was all I could find ATM).
http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0843_zpsbuismri5.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0843_zpsbuismri5.jpg.html)
Replacing it got me this.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0845_zpsp9k0ouku.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0845_zpsp9k0ouku.jpg.html)

I can't get linearity quite right though.....If I do the bottom (and sometimes top) is under-scanned, and centering is maxed downwards.....It's progress though.

This is the HO tube that died. I can't find any ID marks on it.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0841_zpsiluptwfp.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0841_zpsiluptwfp.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0840_zpsk09bppp8.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0840_zpsk09bppp8.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0842_zpsqgojqsvf.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0842_zpsqgojqsvf.jpg.html)

Oh... crap... That's one of my Dentron part numbered tubes. It's an unusual 6LQ6 tube. I tried it in the TV early on, and found it only works in HF amplifiers and not televisions despite being the same number. It's an optimized tube for HF amplification and not television.

Dentron's part number for those is D-50. http://www.radiowrench.com/sonic/so02182.html is what it came out of.

Those... are very expensive and hard to find (At least they were 9 years ago. Not looked in a long time). I forgot it was in that lot of tubes. I need to know if that RCA 6LQ6 tests healthy, if it does I can rearrange the HF amp's tubes and use the RCA as the driver.

If you don't mind test that RCA H-Out tube for me.

Don't worry dude accidents happen. I'm not mad at you. I'm MUCH happier to see a full picture on the screen of that TV then I am upset over a broken Dentron tube.

Electronic M
11-17-2015, 01:38 AM
About done.

I went after the vertical linearity issue this past week. I made sure all resistors in the circuit were good and changed any marginally bad testing caps. One odd thing I found is that a cap in the output cathode circuit was listed as a .47, but the original installed part was a .15uF....I stuck with the value was installed after trying a .47 with no improvement.
I'm not proud of my replacement for that .0082 1KV orange drop....The best I could do, since I don't stock new caps over 630V, was to connect a few 2KV rated blue disc caps salvaged from 90's BPC sets in parallel for the correct value as measured on my cap testers.....Not pretty, but it should function well...It's the kind of thing I regularly put in my sets when there is nothing better on hand, but I prefer not to do that in sets repaired for others (looks unprofessional, and I'm not right there laying in wait to replace if it fails).
http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0904_zps3i5gxkgp.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0904_zps3i5gxkgp.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0908_zpsyfsqyid7.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0908_zpsyfsqyid7.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0909_zpsvvspsiru.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0909_zpsvvspsiru.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0907_zpshvpzz4ud.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0907_zpshvpzz4ud.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0938_zpsf6pwowni.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0938_zpsf6pwowni.jpg.html)

The vertical linearity issues were watchable, but bad enough to bother me.....After all that passive part verification (with little improvement) I was about ready to give up and say the linearity was not going to get better, but then I remembered that when it still had the under-scan issue tube swapping showed linearity differences....So I swapped the vertical tube and things got better...Much better.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0923_zpshurmilbw.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0923_zpshurmilbw.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0921_zpswbki3ezs.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0921_zpswbki3ezs.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0919_zpslp4yz1lr.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0919_zpslp4yz1lr.jpg.html)

One odd thing that happened is that after around 1 hour on the flyback got rather hot....I know because I started smelling wax, then heard a sizzling noise from the HV cage. As soon as that happened I switched it off and opened the HV cage immediately the sizzling continued and was visually confirmed to be coming from the center of the fly windings, and a drop or two of wax had freshly landed on the small existent wax stalagmites. Many of my sets have evidence of this happening before and during my ownership, but I've never seen or heard it in action before....So I don't know whether to interpret this as normal or a warning sign. I had checked cathode current to be just under 200mA not more than 5 minutes before this happened.....
5-10 minutes after powering it off I powered it back on to do a few adjustments for 10-20 minutes....It worked fine, and it did not sizzle again.
Might be a good idea for you to drill some vent holes in the HV cage and add a computer fan to help cool it.

At this point all there is worth doing is to test all the tubes, test the lytics/replace any bad ones (if present) and reassemble it. The cans were cool after over an hour run time, and it's working like a champ, so I'm not sure the tubes and lytics need my attention.....If you want me to I'll go over them, otherwise I could skip them for speed.

Chroma synch has been reliable, but I make no guarantees that it will hold after a bumpy car ride back to your place, so I'll give you some instructions on how to adjust it when you pick it up.

If you are worried about the fly I could work on the CTC-20 after returning the 16....Then if the 16 dies (and if I can fix the 20) I could swap you a working CTC-20....

Let me know what you think.

Arcanine
11-17-2015, 02:10 AM
About done.

I went after the vertical linearity issue this past week. I made sure all resistors in the circuit were good and changed any marginally bad testing caps. One odd thing I found is that a cap in the output cathode circuit was listed as a .47, but the original installed part was a .15uF....I stuck with the value was installed after trying a .47 with no improvement.
I'm not proud of my replacement for that .0082 1KV orange drop....The best I could do, since I don't stock new caps over 630V, was to connect a few 2KV rated blue disc caps salvaged from 90's BPC sets in parallel for the correct value as measured on my cap testers.....Not pretty, but it should function well...It's the kind of thing I regularly put in my sets when there is nothing better on hand, but I prefer not to do that in sets repaired for others (looks unprofessional, and I'm not right there laying in wait to replace if it fails).
http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0904_zps3i5gxkgp.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0904_zps3i5gxkgp.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0908_zpsyfsqyid7.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0908_zpsyfsqyid7.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0909_zpsvvspsiru.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0909_zpsvvspsiru.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0907_zpshvpzz4ud.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0907_zpshvpzz4ud.jpg.html)

The vertical linearity issues were watchable, but bad enough to bother me.....After all that passive part verification (with little improvement) I was about ready to give up and say the linearity was not going to get better, but then I remembered that when it still had the under-scan issue tube swapping showed linearity differences....So I swapped the vertical tube and things got better...Much better.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0923_zpshurmilbw.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0923_zpshurmilbw.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0921_zpswbki3ezs.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0921_zpswbki3ezs.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0919_zpslp4yz1lr.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0919_zpslp4yz1lr.jpg.html)

One odd thing that happened is that after around 1 hour on the flyback got rather hot....I know because I started smelling wax, then heard a sizzling noise from the HV cage. As soon as that happened I switched it off and opened the HV cage immediately the sizzling continued and was visually confirmed to be coming from the center of the fly windings, and a drop or two of wax had freshly landed on the small existent wax stalagmites. Many of my sets have evidence of this happening before and during my ownership, but I've never seen or heard it in action before....So I don't know whether to interpret this as normal or a warning sign. I had checked cathode current to be just under 200mA not more than 5 minutes before this happened.....
5-10 minutes after powering it off I powered it back on to do a few adjustments for 10-20 minutes....It worked fine, and it did not sizzle again.
Might be a good idea for you to drill some vent holes in the HV cage and add a computer fan to help cool it.

At this point all there is worth doing is to test all the tubes, test the lytics/replace any bad ones (if present) and reassemble it. The cans were cool after over an hour run time, and it's working like a champ, so I'm not sure the tubes and lytics need my attention.....If you want me to I'll go over them, otherwise I could skip them for speed.

Chroma synch has been reliable, but I make no guarantees that it will hold after a bumpy car ride back to your place, so I'll give you some instructions on how to adjust it when you pick it up.

If you are worried about the fly I could work on the CTC-20 after returning the 16....Then if the 16 dies (and if I can fix the 20) I could swap you a working CTC-20....

Let me know what you think.

I honestly never thought I would see that TV produce even a half watchable picture. That is as close to perfect as I'd call a set that old.

I would not worry about your repair. I can source a new cap and replace it if your repair ever fails.

As for the Flyback, I had the same thing happen where it got very hot for no reason what so ever. Judging by the wax build up in there, it's been doing that for a very long time for no real reason. Unless it's acting up internally, like windings have fused or something.

Maybe someone here has a spare CTC16 Fly I can get as a spare.

As for the rest of it, it looks like it has a great picture. Pretty excited to see it's alive and working again.

Electronic M
11-17-2015, 12:22 PM
Glad your happy with it. Roundys tend to be a pain in the but to fix for first timers, but often teach them a lot about what can and will go wrong in these sets.

Do you want me to check the tubes and or lytic cans, or should I just bolt it back together and call it done?

Arcanine
11-17-2015, 12:34 PM
Glad your happy with it. Roundys tend to be a pain in the but to fix for first timers, but often teach them a lot about what can and will go wrong in these sets.

Do you want me to check the tubes and or lytic cans, or should I just bolt it back together and call it done?

Yeah go ahead and test them. May as well make sure they're okay before calling it gone be cause I plan to put it in to service and actually watch the thing.

Make sure you find a good 6LQ6, for me, too.

DavGoodlin
11-17-2015, 03:26 PM
This brings back good memories from all the CTC12s-16s I worked on in my HS years, when I had lotsa time:sigh: -
thanks for a great thread

Electronic M
11-17-2015, 07:07 PM
Yeah go ahead and test them. May as well make sure they're okay before calling it gone be cause I plan to put it in to service and actually watch the thing.

Make sure you find a good 6LQ6, for me, too.

Will do.

I have only one good spare 6JS6/6LQ6 in my stocks. I kinda hate to let go of it since that CTC-20 needs one (HO socket is empty), and I have at least 6 working sets that use that tube...

I wish I could trade some other sweep tubes that I have in duplicate++ for some 6LQ6 tubes.

Arcanine
11-17-2015, 07:43 PM
Will do.

I have only one good spare 6JS6/6LQ6 in my stocks. I kinda hate to let go of it since that CTC-20 needs one (HO socket is empty), and I have at least 6 working sets that use that tube...

I wish I could trade some other sweep tubes that I have in duplicate++ for some 6LQ6 tubes.

I sent you a DM about the tube situation, Tom. Keep your spare dude, you have a stack of sets that use it. That TV is the only I have that uses those. I have a half life one I can give you for the CTC20. It'll work in a TV fine, but my HF amp can't use it.

I believe there might be one more label less tube like the broken one in the bunch from me, along with an RCA 6LQ6, and then the 6LQ6 that was actually in the TV it self. I need to know you still have those two, I went looking and I am missing two. Pretty sure I tried two tubes.

old_coot88
11-17-2015, 08:52 PM
...
I have only one good spare 6JS6/6LQ6 in my stocks.
You meant 6JE6, right? (6JS6 is 12 pin.)

Electronic M
11-18-2015, 01:45 AM
Not counting the broken tube or the tube presently installed in the CTC-16; I have 3 loose 6LQ6 tubes in the boxes you brought me. One unmarked (likely Dentron), one RCA and one Sylvania. The unmarked one tests 50 on my tester (upper end of the bad tube zone), the others test in the 90 range.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0928_zpsn9nxxzg9.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0928_zpsn9nxxzg9.jpg.html)

I tested almost all the tubes you brought me (three in the brown box and the ones in the CTC-20 were not gotten to yet). One 6GH8 in the boxes was bad. I replaced a bunch of tubes in the CTC-16 most tested healthy, but failed the grid emission and or short test of my tester....There were some weak ones, the HV rectifier, the audio output, and the 6GH8 that was NOT in the chroma osc. circuit.....Both 6GH8s were replaces since both failed in some way. Your set also now has one of two nuvistors I've had in my stocks for years....I was dumbfounded that I was able to locate one, and that it was the right type.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0927_zps4yxe8r7v.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0927_zps4yxe8r7v.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0926_zps1us1lhje.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0926_zps1us1lhje.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0924_zpsmvfwdbws.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0924_zpsmvfwdbws.jpg.html)

The tubes that are not weak (most of them) likely would be fine to use, but I replaced them with better ones (mostly from my stocks) anyway....You can use the old ones as spares since it was working fine with them in place. I also put two of my good 6GU7s into the spares bucket to make up for the original I ruined.
The new tubes did not significantly change the performance aside from (I think) better color lock, and reception strength.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0925_zpsubdwfeau.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0925_zpsubdwfeau.jpg.html)

BTW the spares boxes contained 2-4 tubes that fit the 20, but not the 16. Do you want those or should I pop them in the CTC-20?

Yes Old_coot, you are right, I either miss-typed or jumbled the number in my head. :no:

I'm going the heck to sleep now. I'm exhausted.

Arcanine
11-18-2015, 02:07 AM
Not counting the broken tube or the tube presently installed in the CTC-16; I have 3 loose 6LQ6 tubes in the boxes you brought me. One unmarked (likely Dentron), one RCA and one Sylvania. The unmarked one tests 50 on my tester (upper end of the bad tube zone), the others test in the 90 range.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0928_zpsn9nxxzg9.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0928_zpsn9nxxzg9.jpg.html)

I tested almost all the tubes you brought me (three in the brown box and the ones in the CTC-20 were not gotten to yet). One 6GH8 in the boxes was bad. I replaced a bunch of tubes in the CTC-16 most tested healthy, but failed the grid emission and or short test of my tester....There were some weak ones, the HV rectifier, the audio output, and the 6GH8 that was NOT in the chroma osc. circuit.....Both 6GH8s were replaces since both failed in some way. Your set also now has one of two nuvistors I've had in my stocks for years....I was dumbfounded that I was able to locate one, and that it was the right type.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0927_zps4yxe8r7v.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0927_zps4yxe8r7v.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0926_zps1us1lhje.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0926_zps1us1lhje.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0924_zpsmvfwdbws.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0924_zpsmvfwdbws.jpg.html)

The tubes that are not weak (most of them) likely would be fine to use, but I replaced them with better ones (mostly from my stocks) anyway....You can use the old ones as spares since it was working fine with them in place. I also put two of my good 6GU7s into the spares bucket to make up for the original I ruined.
The new tubes did not significantly change the performance aside from (I think) better color lock, and reception strength.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0925_zpsubdwfeau.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0925_zpsubdwfeau.jpg.html)

BTW the spares boxes contained 2-4 tubes that fit the 20, but not the 16. Do you want those or should I pop them in the CTC-20?

Yes Old_coot, you are right, I either miss-typed or jumbled the number in my head. :no:

I'm going the heck to sleep now. I'm exhausted.

The unmarked is a Dentron yeah. Internally something is different about them, that they got their own Dentron part number, and refuse to work inside of a television. So as a result they never test quite right. I know it's good because last time I transmitted with the amp on full blast, I was seeing some pretty sweet RF power.

The 6JE6/6LQ6 that's installed in the CTC16 now (Or rather when I delivered it to you) is actually from the CTC20 originally (It's hat looks more like that of a HV Rectifier). I swapped them around. Go ahead and take it out and keep it, and pop my spare RCA back in. That gives you an HO tube for the CTC20 then.

As for the tubes that DON'T belong to the CTC16, those belong to you now. I just popped a pile of tubes out of the CTC20 the final time I decided to mess with the CTC16.

Let's arrange pick up in the next week or two. Mom's car is in the shop currently getting the transmission replaced, so I don't have a warm safe SUV to transport it home in currently. And with it supposed to rain most of this week, the bed of my truck is not a good idea.

And do not buy what the tester says. Jim will chime in and agree, HV Rectifiers never test correctly. They almost always test as bad. Same thing for the Focus 1V2 tube, they test almost bad. You have to remember, the tube usually has 25kW pumping though it, so the tester can't even scratch the surface. Jim and I tested almost 10 of those tubes and they all tested pretty much the same. "Bad"

Findm-Keepm
11-18-2015, 09:32 AM
I honestly never thought I would see that TV produce even a half watchable picture. That is as close to perfect as I'd call a set that old.



Looks great! ElectronicM done you right! Great job!

WISCOJIM
11-18-2015, 01:42 PM
And do not buy what the tester says. Jim will chime in and agree, HV Rectifiers never test correctly. They almost always test as bad. Same thing for the Focus 1V2 tube, they test almost bad. You have to remember, the tube usually has 25kW pumping though it, so the tester can't even scratch the surface. Jim and I tested almost 10 of those tubes and they all tested pretty much the same. "Bad"

Affirmative.

.

Electronic M
11-20-2015, 04:19 PM
The 6JE6/6LQ6 that's installed in the CTC16 now (Or rather when I delivered it to you) is actually from the CTC20 originally (It's hat looks more like that of a HV Rectifier). I swapped them around. Go ahead and take it out and keep it, and pop my spare RCA back in. That gives you an HO tube for the CTC20 then.

Last night I tested all lytics in the CTC-16 for capacitance and leakage up to rated voltage with my Heathkit C3. I completely recapped the C2 and C3 (sam's cap number) cans. Can C2 had 2 leaky and one high ESR section out of 4. C3 had one high ESR section out of 2 sections so I decided to replace the whole thing for good measure. C1 tested perfect, no leakage low esr, so it was left alone.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0937_zpsgboatqy7.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0937_zpsgboatqy7.jpg.html)
I powered it up with your above suggested H out tube swap and the set came on and ran with H centering jitter for 3-10 min before the width shrank greatly which prompted immediate power down. The new ho tube was drawing more than 5ma more cathode current so swapped back to tube that came in the set when I got it....Cathode current is lower and jitter is not present.

I ran it for 1 hour with h out cathode current metered the whole time (it stayed just below 200mA the whole time) and started to hear HV like sizzling and noticed screen noise/h line jitter (multiple clusters of roughly 1-3 h lines would be off center from the rest). I turned it off and the sizzling stopped with power off, opening the cage revealed very mild wax melt (compared to last time), HV winding rubber tire formed warts between HV rect cap cup and the center. It was hottest beneath wart area. The HV rect tube is a RCA 3A3C the chart calls for a 3A3A....I seem to recall once reading that some variants of that tube caused arcing in the CTC-16, but I can't recall it exactly or find it....Could that be the cause?
The tire was VERY soft and pliable in the wart area. I'm really worried that the flyback might not have long for this world.

http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0947_zpsuavg8klh.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0947_zpsuavg8klh.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0946_zpsfseg3ej4.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0946_zpsfseg3ej4.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0939_zpsemddml6c.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0939_zpsemddml6c.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0944_zpswsk1deor.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0944_zpswsk1deor.jpg.html)


And do not buy what the tester says. Jim will chime in and agree, HV Rectifiers never test correctly. They almost always test as bad. Same thing for the Focus 1V2 tube, they test almost bad. You have to remember, the tube usually has 25kW pumping though it, so the tester can't even scratch the surface. Jim and I tested almost 10 of those tubes and they all tested pretty much the same. "Bad"
I don't put much stock in testers results of sweep tubes, but my tester has notes with the settings HV rects...In the case of the 3A3 it says tube good if reads 40 (in the bad scale range) or more. It read 20, and it's replacement read 90 so that is what went in.

I got the CTC-20 together and was able to get a monochrome picture and sound from it.

I'll post some info/opinions in your CTC-16 fly cooling thread latter I have a certain woman SCREAMING at me to do some remodeling work on the house right now.

Arcanine
11-20-2015, 05:39 PM
I wonder if the Tire it self has become conductive? Shango066 on YouTube talks about that a lot on these old RCA sets. And it usually happens in the exact area mine is having major issues with. Right below the hat that the HV Rectifier tube goes in too.

Here is an idea: Carefully see if you can peel the tire off the flyback in the effected area, go to Autozone, or Advance Auto and get Permatex UltraGrey RTV and cover the effected area completely with a layer or two of the RTV to see if that solves the issue it's suffering. It really sounds like the tire has become conductive internally.

Look up Shango066's videos on this. He's repaired much sicker, weaker flybacks this way and it seems to hold up. It's not pretty, but these parts are unobtanium and I cannot afford to source a new fly.

And I don't want to sit with a sick lump of a TV I'm never going to do anything with. I haven't the space to just sit and let it do nothing. I only have room for one single TV this large. If the fly in this set is sick, and you have the patients and time to source a fly, fix the CTC20 and keep the CTC16.

Keep me informed.

Vidoes: https://www.youtube.com/watch?v=BUnPkymnxUw
https://www.youtube.com/watch?v=OHyQo76ySG4

it's not pretty but this might save the CTC16's fly.

Electronic M
11-20-2015, 08:17 PM
I'll examine the fly more carefully to see if I can find what is going wrong.

Would you mind if I drilled a couple of holes in the HV cage so I can see in with it assembled?

The 20 has vertical problems and I have yet to address the coils that are snapped off the rear board.....I don't know if I can get the 20 to work as a color set again (those snapped coils are for color IIRC), let alone by the time you want back at (it might be extra cooperative and come together easy, but I don't want to bet on that yet)....The 16 is working fine aside from the fly issue so I want to try and fix that before I give up and focus on the 20...

I've watched the videos and am willing to try the silicone method if that is what the symptoms merit, but I want to see exactly what it is doing first.

As soon as I can look at it more I'll get back to you.

dieseljeep
11-20-2015, 08:25 PM
I'll examine the fly more carefully to see if I can find what is going wrong.

Would you mind if I drilled a couple of holes in the HV cage so I can see in with it assembled?

The 20 has vertical problems and I have yet to address the coils that are snapped off the rear board.....I don't know if I can get the 20 to work as a color set again (those snapped coils are for color IIRC), let alone by the time you want back at (it might be extra cooperative and come together easy, but I don't want to bet on that yet)....The 16 is working fine aside from the fly issue so I want to try and fix that before I give up and focus on the 20...

I've watched the videos and am willing to try the silicone method if that is what the symptoms merit, but I want to see exactly what it is doing first.

As soon as I can look at it more I'll get back to you.
If someone has a junk CTC19 or a CTC24, the color circuits are the same.

Arcanine
11-20-2015, 09:28 PM
All bets are off. No time frame now, so don't rush. You don't need to rush your self on the 16 or the 20. I'll wait. I don't want to have to sit and worry that fly is going to melt inside it's cage and or burst in to flames if I don't shut it off after under an hour of use. OR the Fly is just going to go KERPOOF after a couple uses and leave all your hard work moot with a dead set. Unfortunately, I'm not able to, or willing to fork over another possible $250 for a "good" flyback plus your labor on that set if that flyback ends up killing it self. That set's future is hanging on it's flyback.

Take. Your. Time. As much as you need.

Feel free to drill and open the cage anyway you need to look inside and see what the fly is doing or aid in cooling it. I'm willing to bet money on that arcing issue, either internally or externally, silently. It's burning the tire in the same exact spot that the videos on youtube. It seems like a simple thing, it's just a bunch of windings inside there, and look at how his was arcing and melting it self, but still worked and keeps working after. Mine is working decently except getting hot with no real explanation and melting the tire in the exact area he mentions in his two videos. I think it's arcing inside the tire and melting it.

Like I said, if you think my fly is sick and I think it's arcing, peel it's tire off and look inside, then seal it back up with RTV. The stuff is only like 4 bucks for a large enough tube to cover the whole flyback. I use Grey all the time, I just used it last week to replace valve cover gaskets on my Ranger.

Electronic M
11-21-2015, 02:00 AM
Looks like it was arcing on the back of the tire.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/DSCN0957_zpsihv5aclu.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0957_zpsihv5aclu.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0956_zpsclgzu2ey.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0956_zpsclgzu2ey.jpg.html)

I wanted to duplicate the arcing behavior so I ran it 20 minutes, and forgot the mirror inside....When the symptoms came back they were fresh ones from the mirror falling between the 11'oclock outer edge of the fly and the cage. Mirror silvering is conductive so all it had to do was melt the plastic edges of the mirror.... After removing the mirror it wanted to arc from the mirror contact point on the tire so I ripped enough off the tire to help, and put a piece of plastic (seen in the last tireless shots) in there to block the spot in the cage it wanted to arc to.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0964_zpsoxp8l7pk.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0964_zpsoxp8l7pk.jpg.html)

I then ran it for almost 2 and a half hours watching it closely, and periodically putting my ear next to the cage to listen for bad noises in hopes the blackened back top of the tire would arc to prove my theory that it was the cause of yesterday's 1 hour arcing.....Nothing happened in those 2+ hours! It worked fine. The tire was warm at the end and some external wax was on the edge of melting/slightly melty, but the only reason I had to shut it off was because I was summoned by the folks for a menial task.

I pulled off the back charred section, and came to the conclusion the tire was so loose it might as well be removed entirely. I'll get some silicone tomorrow and give it a new coat.

http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0961_zpssfdmdksb.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0961_zpssfdmdksb.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0960_zpszbifvg27.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0960_zpszbifvg27.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0962_zpswclhvw71.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0962_zpswclhvw71.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0963_zpsx1h6q8dt.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0963_zpsx1h6q8dt.jpg.html)

Here is what I got out of the 20 last night, but forgot to post. :tongue:
http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0955_zpslurjmgtz.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0955_zpslurjmgtz.jpg.html)

Thanks for allowing me time to get it right. I have been pushing to get it done since there is other stuff (my stuff, and others') I want to work on, and honestly I can see why you were/are not a big fan of this set....I'm sort of tired of pouring my energy into it only to find the next thing or get lack luster non-proportional improvements.

It's darn fascinating working on these chassis and seeing what they are all about compared to others I've seen/worked on, but now my curiosity is sated and from this experience I can say I don't think I'll ever actively seek out another CTC-16 or 20....These sets remind me why I'm (mostly) a Zenith man.

Arcanine
11-21-2015, 03:43 AM
Looks like my theory and hours of watching Shango's videos paid off.

Remember to peel off that beige silicone stuff that he removed in the second video to make sure there is no carbon tracking on the fly it self behind that gross stuff.

Go to the car parts store and get the Permatex UltraGrey. Automotive RTV lacks the acids, as Shango mentioned in the videos, and it can withstand very high voltage, is completely non-conductive. And it can stand up to very high temperatures.

Yeah. Now you see why I passed it on to you for repair. I bought it thinking it was working well and would be simple to keep going. In reality it was very sick and in very bad shape internally and it needed a lot more work then I knew how to give it...

I'm super excited to see it working again and look forward to seeing it in person once it's complete.

I'm glad to see the CTC20 has life. If you can fix or source those coils, I bet it'll come back to life. It's a fairly nice set honestly, I wish it had better care when it was being stored so it would have survived better. Makes me feel even better that it works, you'll get the cash you asked for. You got a Roundy that works with a good CRT and a lot of potential, and a couple other bonuses I am tossing in for all the time you put in to this thing for me that I think you'll like =)

Arcanine
11-26-2015, 03:15 PM
This may be interesting to you, Tom.

http://www.videokarma.org/showthread.php?t=254649

I found the original thread from Colin when he found the CTC20 back in 2012. It looks like the TV worked pretty well. I would try and bring it back to life if I were you. If you can't fix those snapped off coils, I would try and source them.

If down the road you decide to sell the CTC20, I'll be first in line to get it back. I actually find it to be extremely attractive. I'd make the space to have it with the CTC16 =)

Electronic M
11-26-2015, 11:40 PM
I got the old silicone off and recoated the fly for the CTC-16 on Saturday. It went well, and aside from the rubber tire being charred/bubbled there were no scorch marks or carbon tracks to be found (the old silicon and fly paper were fine).
http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0965_zps0qt22sf6.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0965_zps0qt22sf6.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0966_zpsrdlqupoy.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0966_zpsrdlqupoy.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0968_zpsfytwlplj.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0968_zpsfytwlplj.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0969_zpspwofhwxc.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0969_zpspwofhwxc.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0970_zpsdnfeojma.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0970_zpsdnfeojma.jpg.html)
http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0971_zpso9swbuzc.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0971_zpso9swbuzc.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0972_zps4a2w4bt7.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0972_zps4a2w4bt7.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0973_zpstdxliusp.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0973_zpstdxliusp.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0974_zpssgsptye4.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0974_zpssgsptye4.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0975_zpsnyuan3gv.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0975_zpsnyuan3gv.jpg.html)

I decided not to smooth it since a rough surface has more surface area, and thus should cool better.

I gave it about 1.5-2 hours run time with the silicone still soft (which cured it nicely), and it ran like a champ the whole time.

Then I got sidetracked till last night upgrading my laptop to Windows 10 (long story).

I gave it another hour and 40 minutes on. No, arcing, no wax ooze, but the fly does get rather warm...I want to try and find some time to put 3-6 continuous hours on it to see how it holds up. When I can I'll get some heat sink compound for the fly to chassis (may also squirt some between the windings and core). I'll also try to add some vent holes and a fan to it, but I gotta figure out where and which fan (the best side to put a decent sized fan is against the side of the cabinet, and not usable).


I worked on the 20 today. I resoldered the busted coax to the color level control, and resoldered the snapped off chroma transformers.....It came on, a moment later I hear a snap and the vertical fills out.:thmbsp: Then I proceed to adjust what I believe is the chroma osc. transformer and start to get color barber-poling.....Then another snap, raster is lost, and smoke from the area of the chroma osc. transformer. I swap the two leads I guessed the connection points to, and try to reassemble it, but the bottom has melted/warped to the point where I'm not sure that transformer is worth fixing anymore....The vertical relapsed to not filling the screen too. That CTC-20 is a real mess.

I think I'll work on something else for an hour or two to get a break from RCA color work.

Findm-Keepm
11-27-2015, 12:12 AM
I gave it about 1.5-2 hours run time with the silicone still soft (which cured it nicely), and it ran like a champ the whole time.



Heat doesn't cure RTV, only exposure to air and time. Room Temperature Vulcanizing. Heat may open air passages (tunnels) within the RTV, which is why the DoD bans heat application to RTV products. If you are trying to seal up something, why heat it and create tiny tunnels?

Now epoxy, yes - heat that stuff! It shortens the cure time, and makes bubbles trapped within to pop, making for a better cure. But RTV, no.

Arcanine
11-27-2015, 12:28 AM
I got the old silicone off and recoated the fly for the CTC-16 on Saturday. It went well, and aside from the rubber tire being charred/bubbled there were no scorch marks or carbon tracks to be found (the old silicon and fly paper were fine).
http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0965_zps0qt22sf6.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0965_zps0qt22sf6.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0966_zpsrdlqupoy.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0966_zpsrdlqupoy.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0968_zpsfytwlplj.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0968_zpsfytwlplj.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0969_zpspwofhwxc.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0969_zpspwofhwxc.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0970_zpsdnfeojma.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0970_zpsdnfeojma.jpg.html)
http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0971_zpso9swbuzc.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0971_zpso9swbuzc.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0972_zps4a2w4bt7.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0972_zps4a2w4bt7.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0973_zpstdxliusp.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0973_zpstdxliusp.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0974_zpssgsptye4.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0974_zpssgsptye4.jpg.html) http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0975_zpsnyuan3gv.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0975_zpsnyuan3gv.jpg.html)

I decided not to smooth it since a rough surface has more surface area, and thus should cool better.

I gave it about 1.5-2 hours run time with the silicone still soft (which cured it nicely), and it ran like a champ the whole time.

Then I got sidetracked till last night upgrading my laptop to Windows 10 (long story).

I gave it another hour and 40 minutes on. No, arcing, no wax ooze, but the fly does get rather warm...I want to try and find some time to put 3-6 continuous hours on it to see how it holds up. When I can I'll get some heat sink compound for the fly to chassis (may also squirt some between the windings and core). I'll also try to add some vent holes and a fan to it, but I gotta figure out where and which fan (the best side to put a decent sized fan is against the side of the cabinet, and not usable).


I worked on the 20 today. I resoldered the busted coax to the color level control, and resoldered the snapped off chroma transformers.....It came on, a moment later I hear a snap and the vertical fills out.:thmbsp: Then I proceed to adjust what I believe is the chroma osc. transformer and start to get color barber-poling.....Then another snap, raster is lost, and smoke from the area of the chroma osc. transformer. I swap the two leads I guessed the connection points to, and try to reassemble it, but the bottom has melted/warped to the point where I'm not sure that transformer is worth fixing anymore....The vertical relapsed to not filling the screen too. That CTC-20 is a real mess.

I think I'll work on something else for an hour or two to get a break from RCA color work.

I think with the CTC20 it's going to come down to sourcing good replacements for those two transformers... I wish better care had been taken when it was stored disassembled. I like the style, I may wanna buy the set back, so I'd be interested in helping seek the parts.

I'd almost be interested in coming up there and learning from you while you work a little. Learn the basics I'm missing from you, that stumped me so endlessly with the CTC16. How to read and test resistors, check voltages properly, test capacitors.

As for cooling the CTC16's flyback, I was thinking of putting a small, low voltage brushless computer fan on the bottom of the right side of the flybox (Facing it with the back of the set off), blowing in on the transformer, with a vent hole on the top left side to blow the heat out. It would only take a low voltage wall-wart to power a computer fan, which could easily be wired to the TV's cord and switch, so when the set is switched on, the fan powers on. Brushless computer fans are very quiet and move plenty of air. I have several plus several power supplies laying around that'd drive it perfectly.

I'm going out of state in a few days and I'll be gone until December 10th. so while I am gone, feel free to watch and enjoy my CTC16 all you like. Besides the warm flyback, I would certainly call it done.

Windows 10 sucks so far. If you want Windows 7 I have an unlocked installer that I can give you that updates it self and is fully featured. I'm giving you a pretty high end business grade dell laptop as a bonus for all the work you did on the CTC16. it'll have Windows 7 Professional installed on it and I'll include a DVD of the reinstall stuff for you.

Arcanine
11-27-2015, 12:41 AM
Heat doesn't cure RTV, only exposure to air and time. Room Temperature Vulcanizing. Heat may open air passages (tunnels) within the RTV, which is why the DoD bans heat application to RTV products. If you are trying to seal up something, why heat it and create tiny tunnels?

Now epoxy, yes - heat that stuff! It shortens the cure time, and makes bubbles trapped within to pop, making for a better cure. But RTV, no.

Having worked in the Automotive Industry for the last 11 years, and having sold parts for the last 3 years, I feel I can step in.

You're right, heating it will create bubbles, but UltraGrey, UltraBlack, and the more modern RTV's set up with in an hour of being applied, and cure fully with in 24 hours. It can be placed in to service with in an hour.

Also, we're talking about a hot engine block, not a paper & wax flyback transformer in a vintage television. The flyback doesn't get nearly as hot as an engine. It's heat did nothing to aid in making bubbles, or curing it any faster then it would cure anyway.

I requested he used UltraGrey because of that reason, and because I have had amazing personal success sealing up leaky Flybacks with it before. I keep a small tube in my toolbox. Sony Fly's are notorious for splitting in the center of their hard plastic "tire" and leaking out high voltage and arcing. I just slather a little UltraGrey on, let it cure, and the voltage leaks are gone.

Just my two cents. You are 100% right, it will have that issue on a smoking hot engine, but a warm flyback won't effect it in the same manner.

Findm-Keepm
11-27-2015, 01:15 AM
Having worked in the Automotive Industry for the last 11 years, and having sold parts for the last 3 years, I feel I can step in.

You're right, heating it will create bubbles, but UltraGrey, UltraBlack, and the more modern RTV's set up with in an hour of being applied, and cure fully with in 24 hours. It can be placed in to service with in an hour.

Also, we're talking about a hot engine block, not a paper & wax flyback transformer in a vintage television. The flyback doesn't get nearly as hot as an engine. It's heat did nothing to aid in making bubbles, or curing it any faster then it would cure anyway.

I requested he used UltraGrey because of that reason, and because I have had amazing personal success sealing up leaky Flybacks with it before. I keep a small tube in my toolbox. Sony Fly's are notorious for splitting in the center of their hard plastic "tire" and leaking out high voltage and arcing. I just slather a little UltraGrey on, let it cure, and the voltage leaks are gone.

Just my two cents. You are 100% right, it will have that issue on a smoking hot engine, but a warm flyback won't effect it in the same manner.

And I've used RTV many times for corona prevention before - but conductive tracking does occur, and only at high voltages - where the RTV was heat cured and paths for corona were created.

I've serviced TVs since the 70s, dealt with corona and arcing in 55KV AWG-9 radar transmitter power supplies, 16KV Conrac monitor power supplies, and solved many problems with RTV. But in my humble 30+ years in electronics, I've seen RTV'd flys fail just as often as the originals, and mostly due to the carbon tracks - their death certainly created by heat or disturbed curing. RTV has such a strong dielectric strength that 1/20" will seal against corona in a 50KV system, but one tiny (electron wide) hole is all it takes to fail. Patience and curing at room temperatures, with no disturbance for the allotted time is all that is needed for success.

Now with ATS (Activation Temperature Sensitive) silicone (similar to RTV) products, the crap won't cure without heat, and at a prescribed temperature. I've use it as well - aerospace stuff - we can't afford it - but take some good old RTV3145, the good grey stuff, simply apply and let it cure, no heat. No reason to bake out bubbles that leave a tunnel behind as they head for the surface, setting up a corona/burn path....

Remember, we're trying to save flybacks, not guarantee a kill....

But i digress, it's not my flyback.

Arcanine
11-27-2015, 01:34 AM
And I've used RTV many times for corona prevention before - but conductive tracking does occur, and only at high voltages - where the RTV was heat cured and paths for corona were created.

I've serviced TVs since the 70s, dealt with corona and arcing in 55KV AWG-9 radar transmitter power supplies, 16KV Conrac monitor power supplies, and solved many problems with RTV. But in my humble 30+ years in electronics, I've seen RTV'd flys fail just as often as the originals, and mostly due to the carbon tracks - their death certainly created by heat or disturbed curing. RTV has such a strong dielectric strength that 1/20" will seal against corona in a 50KV system, but one tiny (electron wide) hole is all it takes to fail. Patience and curing at room temperatures, with no disturbance for the allotted time is all that is needed for success.

Now with ATS (Activation Temperature Sensitive) silicone (similar to RTV) products, the crap won't cure without heat, and at a prescribed temperature. I've use it as well - aerospace stuff - we can't afford it - but take some good old RTV3145, the good grey stuff, simply apply and let it cure, no heat. No reason to bake out bubbles that leave a tunnel behind as they head for the surface, setting up a corona/burn path....

Remember, we're trying to save flybacks, not guarantee a kill....

But i digress, it's not my flyback.

I have my fingers cross that Tom did it well and no tracking happened.

You like the CTC16 chassis. Do their flybacks normally run a tad on the warm to almost hot side?

Findm-Keepm
11-27-2015, 02:04 AM
I have my fingers cross that Tom did it well and no tracking happened.

You like the CTC16 chassis. Do their flybacks normally run a tad on the warm to almost hot side?

Warm to the touch. I use the back of my finger to test. I can hold my finger there for as long as I want, not hot.... Too hot, and you've got any of the problems I mentioned in the other thread.

Only RCA flys that ran hot were in some of the 19" tube portables - the pulse regulator sets, as we called them. The load vs size got them hot, but I can't recall one ever failing. We used one as a loaner and the only problems were usually related to the 5GH8s. Too unreliable to sell, so we kept 'em for loaner sets.

I like all RCA color sets, up to the CTC175, and any with a MST/MSC module....

The CTC16 was RCAs largest-selling tube sets, with the exception of the CTC38 (another flyback eater, 119834), IIRC. The 16 was extended in the CTC16X, so those numbers were thrown in too.
Somewhere in Google books is a book about Japanese dumping, and the EIA production numbers for domestic sets from 1964 to 1970, by brand, is listed. RCA creamed the competition in the mid-60s, but Zenith and others caught them by 1970, through initial quality and features. We sold and serviced RCA until 81, then it was just servicing. Mass merchandisers were selling sets cheaper than we could get them from RCA, but we didn't buy entire railroad carloads at a time either....

Back to the flybacks - read the service clinic articles in Radio Electronics and Electronics World magazines - authors such as Jack Darr, Art Margolis, Carl Babcoke, and Homer Davidson - these guys were servicers that got to write about it, and dogged many a chassis to find the unlikely culprit. But Darr and others also wrote about prevention of problems (callback avoidance) and how to get a set healthy for the long haul. Not too many specifics, but enough generalities to get a sense of what to check....all of their stuff is over on AmericanRadioHistory - the search engine is wonky, so try different combinations to find what you are looking for. Oh, and the January Issue of Radio Electronics in the 60s generally was their "Color TV" issue, with more articles on Color TV than the rest of the year's issues....

Findm-Keepm
11-27-2015, 02:17 AM
Here's just one service clinic, this one dealing with Boost voltage, but in the artilcle, Jack Darr gives up some info on HOT current and why it may be high:

http://www.americanradiohistory.com/hd2/IDX-Consumer/Archive-Radio-Electronics-IDX/IDX/70s/1979/Radio-Electronics-1979-11-OCR-Page-0070.pdf

Boost cap leaky or shorted, or a shorted winding in yoke - both can cause HOT current to increase, and cook the fly.

Here, the biggest killer of flybacks and yokes was heat and humidity, something our region has plenty of during the summer, when the TV was used as a babysitter for the kids. "The kids said it went fuzzy, then white, and then it smoked. They said they didn't touch it...." Dead give away, either a bad fly, or a focus rectifier stick gave up the ghost.

Electronic M
11-27-2015, 02:45 PM
Findem Keepim: I did give it around 15-25 min to dry before reassembling the cage and running it. I've never needed to use a caulk or corona dope to fix an arcing/corona problem before (previous issues I've dealt with were solved by cleaning dirt off insulators and or replacing bad HV wire). I only ran it that way because in the youtube videos by Shango66 that Arcanine pointed me to for reference Shango66 seemed to do the same thing: remove old material, caulk and turn it back on with the caulk wet....I'll remember to give it more dry time next time I need to do this. Wish I'd known before I did it....

The issue with fly warmth is that the cathode current is on the low end of the range. I don't think it's exceeding the back of the hand contact rule, but it still bugs me how warm it gets.

I think with the CTC20 it's going to come down to sourcing good replacements for those two transformers... I wish better care had been taken when it was stored disassembled. I like the style, I may wanna buy the set back, so I'd be interested in helping seek the parts.

I'd almost be interested in coming up there and learning from you while you work a little. Learn the basics I'm missing from you, that stumped me so endlessly with the CTC16. How to read and test resistors, check voltages properly, test capacitors.

As for cooling the CTC16's flyback, I was thinking of putting a small, low voltage brushless computer fan on the bottom of the right side of the flybox (Facing it with the back of the set off), blowing in on the transformer, with a vent hole on the top left side to blow the heat out. It would only take a low voltage wall-wart to power a computer fan, which could easily be wired to the TV's cord and switch, so when the set is switched on, the fan powers on. Brushless computer fans are very quiet and move plenty of air. I have several plus several power supplies laying around that'd drive it perfectly.

I'm going out of state in a few days and I'll be gone until December 10th. so while I am gone, feel free to watch and enjoy my CTC16 all you like. Besides the warm flyback, I would certainly call it done.

Windows 10 sucks so far. If you want Windows 7 I have an unlocked installer that I can give you that updates it self and is fully featured. I'm giving you a pretty high end business grade dell laptop as a bonus for all the work you did on the CTC16. it'll have Windows 7 Professional installed on it and I'll include a DVD of the reinstall stuff for you.

If you want to buy the 20 back from me later I'd be open to that. If you want to come over and work on stuff with me some time I'm cool with that.

It did not look like there is a enough clearance between the side of the cabinet and the side of the HV box for a fan, but I can recheck. A separate PS is not really necessary. It's fairly easy to rectify the set's heater line, add a filter cap so the fan sees clean enough DC, and a small user fan switch in a discreet place.

The laptop sounds awesome! :thmbsp: I have my own windows 7 install disc that I've used with several machines. The 10 installation was a free upgrade from 7 on my school machine, and most of the time spent was preparing the Win 7 OS for a drive image backup (closing/saving the mountain of open stuff that being on for a few weeks-months straight accumulates, moving files to external drive to shrink the size of the backup image, defragmentation, run anti-virus, etc.). With the drive image backup I can go back to Win 7 anytime, or throw the image on another drive and go between them by drive swapping.
I like Win 10 so far. The back end is better programmed and it runs better/faster on my laptop than 7 did. There are a couple of things about the look of the taskbar I dislike, but I'll fix or get over them. I also hate the change in mouse commands for photo viewer (makes reading Manga a PITA), but there should be ways around that.

BTW: I got that little Admiral going last night. It was the ion trap that was extinguishing raster. It has a funky intermittent in the tuner (I believe) that kills all reception, but it can be persuaded to work. I recapped the IF board since that was easy with the back off. It is rather dim yet so I plan to test the CRT.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/Temporary/th_DSCN0991_zpsvljxhr1w.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Temporary/DSCN0991_zpsvljxhr1w.jpg.html)

marty59
11-27-2015, 03:59 PM
Quote: "The HV rect tube is a RCA 3A3C the chart calls for a 3A3A....I seem to recall once reading that some variants of that tube caused arcing in the CTC-16, but I can't recall it exactly or find it....Could that be the cause?"

There seems to be some variance in the height of the tube(s) and the "C" versions may be somewhat shorter, causing issues with the tube contacting the top of the flyback. There should be enough slack/adjustability in the top cover as it sets in place but good to verify.

Arcanine
12-16-2015, 11:13 PM
Any updates on this? My DM's not making it though?

I'm starting to miss it~

Electronic M
12-17-2015, 04:40 AM
It is basically as I left it in the last post (started other projects and left it as is). I tried to unbolt the fly to put heat-sink compound between it and the chassis for better cooling, but the bolts holding the fly are stubborn, and after trying every safe hand tool I have and penetrating oil with no results....I decided I rather not do it than start trying things that might risk damaging the flyback. I probably should look for a high line voltage tap on the primary of the power transformer and if there is one connect it...I did not install the cooling fan (but I'll give you some fans, parts and advise if you want)...I should also try to make a line bucking transformer for you...

I sent you a PM.

old_coot88
12-17-2015, 10:21 AM
The line voltage tap is easy to spot. It's on a terminal strip under the chassis, right under the power xfmr area. Look for a terminal with only one wire and nothing else going to it.

DaveWM
12-17-2015, 11:10 AM
I have looked into cooling fans. The only set I have one on is a CTC-5 due to the rarity of the FLY. One thing to remember about vintage TV's do NOT leave them on unattended, even for just a few minutes. They are WAY past any expected use date and the flys were an issue even back when new. The concern I have over forced air cooling is IF the fly still manages to overheat, you will have a blow touch on your hands. The flys tend to be in a confined steel box I presume on reason was safety, as in fire containment. Adding the fan pumping oxygen to a burning lump of tar will really stoke the flames.

miniman82
12-18-2015, 09:29 PM
5 flybacks are super easy to find, I have one here you want it? It's the 4's and 21-CT-55's that are near impossible to replace, in fact I'd take the fly out of my Wingate and replace it with one from a 4 if I had one to spare. A Wingate with stiff HV would be a super nice set to watch, too bad they made 'em wrong from the jump.