Hello! I thought would ask the pro's of any suggestions and tips for my RCA 16XL. Is there is any must/recommended do's or things to look out for? It is in fairly good shape, looks to have very little work done to it and mostly original condition. The CRT tests really strong on a CR70 and has a great color picture. The flyback looks to be ok and does not have any leakage under it and that's nice to see.
However the vertical is a bit outta wack and no way to fill screen without stretching the top. Horizontal is close with the control at its max so I suspect I need to be checking out them sections for drifted components.

Also, is there a way to protect the flyback from melting down or failing? What kind of failure usually causes this so I can keep a look out for that. I thought a while back I read that there was a way to fuse it to help protect them, but for the life of me I cant seem to find where I read that at.

I'm excited to get this thing going :D Looking forward to watching Star Trek the original series weekdays on broadcast :D

I just want to say thank you to everyone for your input and help!

Oh, I did get a copy of the Sams manual as well

Hello fellow 16XL owner!! :)
Glad to hear yours is working so well... ( mine is not, No color via tuner, was the orig prob when I got it, then it sat for many years... )

First and foremost, in order to keep the FB safe cool and happy ( as I have seen it stated many times )
run through the horizontal sweep circuit adjustments ( page 7 under Misc, adjustments )
MOST important is the cathode current on v12 horizontal output.

Now many have stated that the electrolytics in these sets degrade quite a bit over time and are not quite up to the task any more, I have replaced most of mine, and it has made quite an improvement, but I'm still having a big headache with resistors that are too far out of spec. :(

Hey fellow 16XL owner! I have been reading about yours, quite a journey so far! I am sure you will get it squared away :D I am thinking maybe I will go ahead and replace all them electrolytic caps. I will have to keep ya updated on my findings. I think this weekend I am going to take on that cataract problem our sets have. wish me luck! lol

Who doesn't love seeing pictures of these old sets up and working :D

Needs a cataract surgery. Picture looks nice otherwise.

Indeed, I just finished the surgery too. First time doing it and was worried id ruin the tube, but it turned out good! now on to the electronics since I didn't blow it up lol

For the vertical problem, check the electrolytic capacitor in the cathode circuit of the output stage. Also, check the decoupling capacitor on the B+ end of the output transformer.

Thanks Tim! I will check them out

hi rocket, please check R102 150 K . that is between vertical height and vertical linearity. this resistor causes many different symptoms height adjustments. and it is common to fail in old sets. that is a part that I personally change every time with the original specification or a small increase in wattage.

hi rocket, please check R102 150 K . that is between vertical height and vertical linearity. this resistor causes many different symptoms height adjustments. and it is common to fail in old sets. that is a part that I personally change every time with the original specification or a small increase in wattage.


CTC-16 vs CTC-16XL confusion bites again. :o
The resistor you refer to ( r102) is only present in the CTC-16 and not the CTC-16X (L) version,
The vertical circuits are quite different between the two.

For the vertical problem, check the electrolytic capacitor in the cathode circuit of the output stage. Also, check the decoupling capacitor on the B+ end of the output transformer.

going by the Sams for the CTC-16x (0818-2)

electrolytic capacitor in the cathode circuit of the output stage. - C4 50uf

decoupling capacitor on the B+ end of the output transformer.
C3b 80uf (through r108 1000ohm gets a bit warm ) only draw from 400v tap
I kind of blame RCA for all the confusion :/ the 16 and 16x are SO different, they should have had a seprate #, they even have different tubes in places :o

The vertical on the CTC-16X seems a bit strange :o
Height Pot is normal enough, B+ 390 (1) via r104 through pot r14 to gnd.
It's linearity (r13) that's weird, high side from 970v boost, but then the other side goes all the way to s6 (picture tube bias ) and then to screen grid pots ( via r193 194 )
not really sure what they are doing with this :o

All very good info bluenorm & yamamaya42!

I was looking over the schematic from sams and there is something very close in the 16xl. its R104 at 150k and it looks to be connected right up to the vertical height. R102 is also very close to the vertical height but its value is 3.3 meg and so is R103 at 2.7 meg. I am going to check on these later today and report back my readings : D

R104 has already been replaced from the looks of it. it tested out at 151k
R102 tested at 3.1 meg
R103 tested at 2.8 meg

They are all seem pretty close to spec.

Also noticed C-4 electrolytic has been replaced. Sams shows it as a 50 @ 50v and was replaced with a 47 @ 50v. that is pretty close. not sure if that should get switched out or not. I thought I read something once about its ok to go slightly above but not below spec. but that may have been for the voltage rating now that I think about it more. lol

---

Also noticed C-4 electrolytic has been replaced. Sams shows it as a 50 @ 50v and was replaced with a 47 @ 50v. that is pretty close. not sure if that should get switched out or not. I thought I read something once about its ok to go slightly above but not below spec. but that may have been for the voltage rating now that I think about it more. lol

A 47uf electrolytic is just a standard value that replaces 50uf. The tolerance on electrolytics is usually very wide, so when 50 was specified, the actual value of an individual unit might be anywhere from -20% to +50% or so.

The vert. oscillator plate load resistor frequently goes 'waay out of spec from being hammered by high level spike. This applies across all makes and models, both BW and color. Worth bookmarking.

that kinda explains why your 16-xl works so well and mine does not T_T, yours has been worked on before. mine is all factory orig parts. :( not counting tubes.

Under the 'Suggestions/Tips' heading there's one problem endemic to the CTC-12, '15, '16, '17 and '25. That's the two ground stakes on the far right end of the chroma board. They exist in one of two states; they're either cracked or gonna crack, and should always be re-flowed as a matter of course.

Under the 'Suggestions/Tips' heading there's one problem endemic to the CTC-12, '15, '16, '17 and '25. That's the two ground stakes on the far right end of the chroma board. They exist in one of two states; they're either cracked or gonna crack, and should always be re-flowed as a matter of course.

As i mentioned in the thread for my CTC 16XL, the entire chroma board had been removed at one point ( which i replaced ) when i first got it, I have now found it to be IF related ( not fixed yet ) As I can get color when I inject video at first video amp but not through the tuner. ( which was the orig problem before It was put in storage - no color )
so, they have been resodered on mine

The vert. oscillator plate load resistor frequently goes 'waay out of spec from being hammered by high level spike. This applies across all makes and models, both BW and color. Worth bookmarking.

Bookmarked! :) I am going to check on that one tomorrow

I will also reflow all of them spots as well, thanks for the tips!

that kinda explains why your 16-xl works so well and mine does not T_T, yours has been worked on before. mine is all factory orig parts. :( not counting tubes.

Yeah, I think this thing was well maintained and kept clean and dry for most of its life. I was impressed when I ran across it! So far digging through this chassis it looks like 4 caps and 1 resistor has been replaced. I thought I had little done until now hehe

Took a break from checking caps and resistors and started working on cleaning tube sockets with DeOxit and tube pins as well all the pot controls as they were acting kinda finicky when I noticed that little pin that usually grounds to a tube shield and realized that I'm missing the shield! Took a peak at the schematic to make sure no others were missing. So I gotta find me one of them. Its on the 6gh8a Chroma Reference Oscillator. Kinda curious if any y'all know what kinda problems that missing shield would cause? :scratch2:

Adding or removing the shield could slightly affect the tune of the chroma osc. Shielding is important, but missing shields shouldn't cause harm...Just more noise radiated and or recieved.

Took a break from checking caps and resistors and started working on cleaning tube sockets with DeOxit and tube pins as well all the pot controls as they were acting kinda finicky when I noticed that little pin that usually grounds to a tube shield and realized that I'm missing the shield! Took a peak at the schematic to make sure no others were missing. So I gotta find me one of them. Its on the 6gh8a Chroma Reference Oscillator. Kinda curious if any y'all know what kinda problems that missing shield would cause? :scratch2:

Its prob not SUPER critical, they prob have it there to stop any RF energy from Chroma reference Osc. & control tube (v24 -6GH8A ) from bleeding out all over the place.

Not to be picayunish :)but the colorburst tube is not the oscillator. The burst tube supplies the synchronizing signal for the osc.

Not to be picayunish :)but the colorburst tube is not the oscillator. The burst tube supplies the synchronizing signal for the osc.

Edited

Not to be picayunish :)but the colorburst tube is not the oscillator. The burst tube supplies the synchronizing signal for the osc.
And they are timed by a horz pulse to grab & amp the 8 burst
signals on the back porch.

73 Zeno:smoke:
LFOD !

It's a miracle they ever got color working at all (and still have it compatible with B/W ) And when it did work, It was... Never The Same Color! ( my electronics taught us that one )
along with...
Bad Boys Rape Our Young Girls But Violet Goes Willingly … :o
There was also .. eli the ice man. ( barely remember that )

And they are timed by a horz pulse to grab & amp the 8 burst
signals on the back porch.

73 Zeno:smoke:
LFOD !
..And then the osc. free-runs during the whole scan period (one scan line) before the next synchronizing "burst".

If you still don't get full height, you may have to look at ALL resistors in there...
r98,99 ,100,101, (102,103,104, OK ) 106,107,108...
The only unknown factor is the VDR @ r105, Still not sure how they are ment to act, or test them. ,

I have been putting off checking all the resistors in my set for a while, as I wanted it to sit in an dry climate controlled environment for at least a month or more before I started, I brought it inside early Feb.

Glad the shield isn't super critical, still going to find one to replace it.
This evening going to go back to checking out more components and see what I find.
Don't know why but it's a lot of fun working on these old sets! It is totally amazing we were able to make color work back then and doing it all on fly without microchips and computers! Amazing so cool :)

Glad the shield isn't super critical, still going to find one to replace it.
This evening going to go back to checking out more components and see what I find.
Don't know why but it's a lot of fun working on these old sets! It is totally amazing we were able to make color work back then and doing it all on fly without microchips and computers! Amazing so cool :)

“microchips and computers” Funny you mention that. :p
It's what I have spent the bulk of my life working on ( debug ) since I got out of electronics classes. :p

“microchips and computers” Funny you mention that. :p
It's what I have spent the bulk of my life working on ( debug ) since I got out of electronics classes. :p


Thats awesome!! and here we are working on these vintage sets *lol*

The vert. oscillator plate load resistor frequently goes 'waay out of spec from being hammered by high level spike. This applies across all makes and models, both BW and color. Worth bookmarking.

Did some checking and it was out of spec, it was not really really bad but it was higher than it should be. Also found one on the horizontal section as well.

now that is odd, does yours have an RF shield over the IF board, like shown in the sams on page 17, Chassis top view? mine does not have it, or did not when i got it...

now that is odd, does yours have an RF shield over the IF board, like shown in the sams on page 17, Chassis top view? mine does not have it, or did not when i got it...

Indeed mine does, I went and took a picture for you to compare. I wonder if there are other things we could be missing. I also wonder how hard it could be to come by one of these shields... though could maybe make one out of thin sheet metal.

Which means, most likely that someone was messing with the IF before I got it, &I need someone to make a template from a same model 16xl when they have time, :)

Which means, most likely that someone was messing with the IF before I got it, &I need someone to make a template from a same model 16xl when they have time, :)

If you pull the tubes and cut out for the protruding transformer can you could probably make a usable template out of paper from your own set.

Which means, most likely that someone was messing with the IF before I got it, &I need someone to make a template from a same model 16xl when they have time, :)

Yeah, its a shame that they didn't bother to put the shield back. Also I will be glad to try to work up a template for you from mine ; )

Got a question about properly doing the HV setup. I will be ready to put the chassis in for a test run in the next few days and I want to get this set correctly as one of the first things on my list. I have been reading up on the Sams instructions. Its my first time doing a HV setup so I don't want to botch it and get everything connected up correctly.

I drew up a little thing and attached it.

Please correct me if I am wrong, I pull the top of the horizontal output tube and have my meter in series with that lead as well as a capacitor in series with my meter. Then adjust to get below 210ma while maintaining 24kv on the picture tube anode at normal brightness setting.

Got a question about properly doing the HV setup. I will be ready to put the chassis in for a test run in the next few days and I want to get this set correctly as one of the first things on my list. I have been reading up on the Sams instructions. Its my first time doing a HV setup so I don't want to botch it and get everything connected up correctly.

I drew up a little thing and attached it.

Please correct me if I am wrong, I pull the top of the horizontal output tube and have my meter in series with that lead as well as a capacitor in series with my meter. Then adjust to get below 210ma while maintaining 24kv on the picture tube anode at normal brightness setting.

the Horz current setting is on the CATHODE , not the plate
you will have to interrupt its path to ground. (pin 3)

this may help explain
https://www.boxcarcabin.com/rcacathode.htm

the Horz current setting is on the CATHODE , not the plate
you will have to interrupt its path to ground. (pin 3)

this may help explain
https://www.boxcarcabin.com/rcacathode.htm

Thanks Yamamaya42! That helps a lot : D

the Horz current setting is on the CATHODE , not the plate
you will have to interrupt its path to ground. (pin 3)

this may help explain
https://www.boxcarcabin.com/rcacathode.htm

A useful tip when you disconnect the cathode lug of the socket run a wire from it to the top side of the chassis and add a fuse holder above chassis. Ground one side of the fuse holder, and connect your cathode wire to the other. When you're using the TV as a TV install a 250mA fuse to protect the flyback...If you ever need to check the cathode current all you have to do is pull the fuse and clip your meter to the terminals of the empty fuse holder.

Adding that fuse/holder above chassis both gives your flyback added protection and and gives you a convienent cathode current test point.

A useful tip when you disconnect the cathode lug of the socket run a wire from it to the top side of the chassis and add a fuse holder above chassis. Ground one side of the fuse holder, and connect your cathode wire to the other. When you're using the TV as a TV install a 250mA fuse to protect the flyback...If you ever need to check the cathode current all you have to do is pull the fuse and clip your meter to the terminals of the empty fuse holder.

Adding that fuse/holder above chassis both gives your flyback added protection and and gives you a convienent cathode current test point.

Great tip Tom! Thanks : ) it's now on my list

Yeah, its a shame that they didn't bother to put the shield back. Also I will be glad to try to work up a template for you from mine ; )

that would help a lot, tks. :banana:

that would help a lot, tks. :banana:

sure thing! Least I could do for all the help

I got the template done, drop me a pm with an addy and ill mail it over to ya

A useful tip when you disconnect the cathode lug of the socket run a wire from it to the top side of the chassis and add a fuse holder above chassis. Ground one side of the fuse holder, and connect your cathode wire to the other. When you're using the TV as a TV install a 250mA fuse to protect the flyback...If you ever need to check the cathode current all you have to do is pull the fuse and clip your meter to the terminals of the empty fuse holder.

Adding that fuse/holder above chassis both gives your flyback added protection and and gives you a convienent cathode current test point.


"install a 250mA fuse to protect the flyback. "

I'm guessing slo-blow for this? And the voltage ratings (AC/DC) are not super critical ?

Depends on the current it runs. If it scores in the 170s a slow blow might not catch moderate issues till serious. If it scores in the 210s it may have regular nuisance blows if fast acting (my 21CT55 CTC2b does this).

Voltage rating is almost completely unimportant for fuses... especially given they were nearly all rated for 250v back in the tube era. thanks

Depends on the current it runs. If it scores in the 170s a slow blow might not catch moderate issues till serious. If it scores in the 210s it may have regular nuisance blows if fast acting (my 21CT55 CTC2b does this).

Voltage rating is almost completely unimportant for fuses... especially given they were nearly all rated for 250v back in the tube era. thanks

Hey Tom, what are you thoughts that if it scores higher and is a bit of a nuisance. Would bumping up to a 300ma fast or a 250 slow run a risk of not catching things quick enough? or better off sticking to the 250 fast to be safe

I'd be inclined to stay at 250 and go with slow blow...My gut feeling is the waveform spikes probably aren't going to reliably trip a 300 fast until the average DC current reaches the trip point of a 250 slow...

Another thing to consider is that some sets will have an increase of the static current during warmup or power off or changes in line voltage (which occur if the fridge, climate control, or local power grid your set is on cause voltage fluctuations*).

*That can be dealt with with a Sola VRT/CVT/voltage regulating line isolation transformer.....My local grid sucks so I've been forced to resort to these.

Fuses are cheap so you could probably grab 2-5 of each and experiment on sensitivity if you really want to get it to blow at anything above normal optimized parameters. Ultimately as long as it isn't nuisance blowing and isn't wildly above that point you should be fine...I've seen major non-flyback circuit failure (such as H osc. failure) drive the average cathode current well above 300mA. Most tube color sets that see daily use will need SOMETHING fixed every year or so...Thus if you check cathode current during that service you can catch issues developing.

I'd be inclined to stay at 250 and go with slow blow...My gut feeling is the waveform spikes probably aren't going to reliably trip a 300 fast until the average DC current reaches the trip point of a 250 slow...

Another thing to consider is that some sets will have an increase of the static current during warmup or power off or changes in line voltage (which occur if the fridge, climate control, or local power grid your set is on cause voltage fluctuations*).

*That can be dealt with with a Sola VRT/CVT/voltage regulating line isolation transformer.....My local grid sucks so I've been forced to resort to these.

Fuses are cheap so you could probably grab 2-5 of each and experiment on sensitivity if you really want to get it to blow at anything above normal optimized parameters. Ultimately as long as it isn't nuisance blowing and isn't wildly above that point you should be fine...I've seen major non-flyback circuit failure (such as H osc. failure) drive the average cathode current well above 300mA. Most tube color sets that see daily use will need SOMETHING fixed every year or so...Thus if you check cathode current during that service you can catch issues developing.

Sounds good I already have a 5 pack of the 250ma fast on the way, if I have nuisances and the readings look good perhaps I will try the 250 slow. How often do you have nuisance blows? and did it get any better with the line voltage regulation?

What are you thoughts of them ups battery backups? I currently use a few of them I kept my stuff on. Surprisingly the power doesn't seem that bad around here and it rarely has to kick in. I have noticed that I run a little on the high side around 121vac here. I will have to get out the meter and kick on the fridge and AC to see if I notice any drop in voltage.

In the CTC2 running at ~210-215mA with 250mA fast blows the fuses didn't last more than 3 hours.

Most UPSs I've seen don't regulate the line voltage at all...All they seem to do is switch to battery if the bottom drops out.

It will be hard to catch the most TV-noticeable line voltage change with a meter...When a large induction motor (fridge compressor, climate control, etc) kicks on for an instant it draws more than 5X it's power rating to get started...That drop is too fast for most meters (though if the steady state load is high enough that will register)...When a motor first kicks on you may notice a single flicker of the lights (at least if your still running incandescents like me)...On a tube era TV the raster will bloom with no correlation to video content...It can be very noticeable...There is an industrial park within 2mi of me and sometimes whatever they are doing causes blooming randomly every 3-6 seconds. I know it is the grid when I run 2 tube sets at once and both do it at the same time.

In the CTC2 running at ~210-215mA with 250mA fast blows the fuses didn't last more than 3 hours.

Most UPSs I've seen don't regulate the line voltage at all...All they seem to do is switch to battery if the bottom drops out.

It will be hard to catch the most TV-noticeable line voltage change with a meter...When a large induction motor (fridge compressor, climate control, etc) kicks on for an instant it draws more than 5X it's power rating to get started...That drop is too fast for most meters (though if the steady state load is high enough that will register)...When a motor first kicks on you may notice a single flicker of the lights (at least if your still running incandescents like me)...On a tube era TV the raster will bloom with no correlation to video content...It can be very noticeable...There is an industrial park within 2mi of me and sometimes whatever they are doing causes blooming randomly every 3-6 seconds. I know it is the grid when I run 2 tube sets at once and both do it at the same time.

Wow! indeed that doesn't last long at the high side huh, is it any better around 190 ma?

Yeah I can also see it in the lights, though its not very often. I wonder if an analog meter would do any better than a digital at seeing the fluctuations.

Wow every 3-6 seconds that's crazy! it probably is something in that industrial park

There probably would be a noticable improvement in life. To be honest untill the CTC-2 (I ranout shortly before that) I had been using mostly fuses from electronics I had been scrapping and hadn't checked if what I had was slow blow or not.

BTW: line voltage affects these a good bit. There are usually 2 line voltage taps on the transformer primary on most RCAs having it on the best tap for your line voltage or even runing the set off a variac set for balance between normal picture and minimum H output cathode current is not a bad thing to do.

Couple of other things you can do are to make a ventilation hole in the HV cage and mount a small fan to draw warm air out to cool the flyback. Also on the CTC-16 I serviced for a dead beat (guy still owes me money) that used to be active here. He wanted me to remove the rubber tire on the HV winding and replace it with Silicone based on this video: https://www.youtube.com/watch?v=BUnPkymnxUw which I sucessfully did for him. Apparently the rubber beraks down and becomes conductive sometimes as it ages.

Sounds good I already have a 5 pack of the 250ma fast on the way, if I have nuisances and the readings look good perhaps I will try the 250 slow. How often do you have nuisance blows? and did it get any better with the line voltage regulation?

What are you thoughts of them ups battery backups? I currently use a few of them I kept my stuff on. Surprisingly the power doesn't seem that bad around here and it rarely has to kick in. I have noticed that I run a little on the high side around 121vac here. I will have to get out the meter and kick on the fridge and AC to see if I notice any drop in voltage.

like he said, a UPS wont help, but a Line Conditioner will, if you were really willing to spend the $$$ for it..

they work by converting the AC in to DC then back to stable AC, so no fluctuations in make it out.
example
https://www.amazon.com/Tripp-Lite-LC1800-Conditioner-Outlet/dp/B0000514G8

There probably would be a noticable improvement in life. To be honest untill the CTC-2 (I ranout shortly before that) I had been using mostly fuses from electronics I had been scrapping and hadn't checked if what I had was slow blow or not.

BTW: line voltage affects these a good bit. There are usually 2 line voltage taps on the transformer primary on most RCAs having it on the best tap for your line voltage or even runing the set off a variac set for balance between normal picture and minimum H output cathode current is not a bad thing to do.

Couple of other things you can do are to make a ventilation hole in the HV cage and mount a small fan to draw warm air out to cool the flyback. Also on the CTC-16 I serviced for a dead beat (guy still owes me money) that used to be active here. He wanted me to remove the rubber tire on the HV winding and replace it with Silicone based on this video: https://www.youtube.com/watch?v=BUnPkymnxUw which I sucessfully did for him. Apparently the rubber beraks down and becomes conductive sometimes as it ages.

I will keep on eye on the fuses and the power draw and report back how well it goes.

Thats good to know about these sets. I think it may be worth it even if my line voltage isn't as bad it still would be better from what I've taken notice here the last few days.

I really like the idea to ventilate the flyback cage, I've been thinking about doing that as well. I really would like to do what I can to keep the flyback good. I can't believe that they put a tube in a metal box with the flyback, its gotta get pretty hot in there. I did notice though that the tube says it has X-ray radiation and perhaps maybe that's why they have it in a cage. I wonder if there would be X-ray leakage with drilling in some holes at the top that one would be concerned about :scratch2:

Is there any signs when the rubber becomes conductive and becomes a problem? I may give it a shot in the future and try to do that as well. Really sucks someone didn't pay you for your work, that's the worst.

like he said, a UPS wont help, but a Line Conditioner will, if you were really willing to spend the $$$ for it..

they work by converting the AC in to DC then back to stable AC, so no fluctuations in make it out.
example
https://www.amazon.com/Tripp-Lite-LC1800-Conditioner-Outlet/dp/B0000514G8


Thats a pretty nice line conditioner, I believe you and Tom got me convinced : D lol and from keeping an eye on things around here, it could probably use it. I was about to look up how exactly it works as well hehe

I am now curious what the efficiency of this unit is converting ac to dc and back to ac again.

Something akin to these is what I use. https://www.alliedelec.com/circuit-protection/constant-voltage-transformers/?category=2%7C2510416%2F1643984&a7=In%20Stock%20Only

The way I understand it there is a motor run cap inside that regulates the power through a resonance effect. They can hold outut voltage rock stable with anything between 90-140 input...Heck they can even hold stable output voltage through a missing cycle or two of input.

I see new ones are stupid expensive...I got all of mine by haunting Hamfests and antique radio swapmets...I don't think I paid over $25 a pop for mine. Every one of the 4 I've got was a good purchase, and I'm still lookin for more.

The advantage of a CVT is there is no switch mode supply to potentially generate RF hash on the line...Also fewer parts means less to go wrong.

Something akin to these is what I use. https://www.alliedelec.com/circuit-protection/constant-voltage-transformers/?category=2%7C2510416%2F1643984&a7=In%20Stock%20Only

The way I understand it there is a motor run cap inside that regulates the power through a resonance effect. They can hold outut voltage rock stable with anything between 90-140 input...Heck they can even hold stable output voltage through a missing cycle or two of input.

I see new ones are stupid expensive...I got all of mine by haunting Hamfests and antique radio swapmets...I don't think I paid over $25 a pop for mine. Every one of the 4 I've got was a good purchase, and I'm still lookin for more.

The advantage of a CVT is there is no switch mode supply to potentially generate RF hash on the line...Also fewer parts means less to go wrong.

Wow that's impressive it can hold stable of a missing a cycle or 2! Probably more efficient than the ac-dc kind as well. Really don't want any RF hash on the line as well. It is a shame they are so expensive. I will have to keep an eye out at the swapmeets and perhaps I can pick up one for a better price.

Well I did my first power up today to check my progress and it looks as though I have made my situation worse. I lost even more of my vertical height, was just a horizontal line at first, but the controls let me bring the line down a few inch's. I was able to bring up the upper vertical but not as much as before as well. but it looks like most of the picture is squeezed in a few inch's. I did try another vertical tube just to rule it out.

Here's what I've done so far,
Cleaned up all the pot controls and switches and they all seem to work much better now. cleaned up all the tube pins and sockets with DeOxit

replaced 2 paper/wax caps under the hood
Also under the hood R130 and R125 connected on the horizontal output tube was pretty well out of tol.
I also replaced that 150K everyone talked about, think that was r104. it drifted to about 8% so I nabbed it also.

up top on the sweep board R97 was past the edge so I replaced that one. Had to lift R82 to read it and it wasn't too bad but had drifted a bit so I nabbed it.

Going to pull the chassis back out tomorrow and recheck all my work.

Any suggestions on where to look and test for I'm all open ears

Start with all the electrolytic caps in the vertical (IIRC one is mounted on the convergence board). Change the orange/maroon drops in the vertical stage too if the lytics are not it. Many say drops don't fail, but in sweep stages and some in the color stages close to tubes do go bad in these sets (I've tested caps for leakage to full working voltage on my Heathkit C3 to learn this).

Well I did my first power up today to check my progress and it looks as though I have made my situation worse. I lost even more of my vertical height, was just a horizontal line at first, but the controls let me bring the line down a few inch's. I was able to bring up the upper vertical but not as much as before as well. but it looks like most of the picture is squeezed in a few inch's. I did try another vertical tube just to rule it out.

Here's what I've done so far,
Cleaned up all the pot controls and switches and they all seem to work much better now. cleaned up all the tube pins and sockets with DeOxit

replaced 2 paper/wax caps under the hood
Also under the hood R130 and R125 connected on the horizontal output tube was pretty well out of tol.
I also replaced that 150K everyone talked about, think that was r104. it drifted to about 8% so I nabbed it also.

up top on the sweep board R97 was past the edge so I replaced that one. Had to lift R82 to read it and it wasn't too bad but had drifted a bit so I nabbed it.

Going to pull the chassis back out tomorrow and recheck all my work.

Any suggestions on where to look and test for I'm all open ears

That's why I chose not to do too much of an area at once, example, my first target was the v6 area, replace what I think may be bad, then re-power on to see if there is any drastic change.
My next target is the V1/V2 area.

Pick a section at a time, and test the set a LOT as you go.

I believe I have all the electro's changed out except for the 3 big cans, and I was contemplating them, but I wanted to test the set first to see how things were looking. I will pull the chassis back out after work today and check my work, then check to make sure about all the electro's, I need to take a look at the convergence as I have not done that. I did clean up all the pot controls on it with DeOxit though. then if all looks well, I will start on the drops. I don't have a way to test to full voltage so I may just get all the drops in the vertical section.

yeah, not a bad idea about testing the set as you go : D

Start with all the electrolytic caps in the vertical (IIRC one is mounted on the convergence board). Change the orange/maroon drops in the vertical stage too if the lytics are not it. Many say drops don't fail, but in sweep stages and some in the color stages close to tubes do go bad in these sets (I've tested caps for leakage to full working voltage on my Heathkit C3 to learn this).

This did the trick Tom! I went ahead and replaced all the orange/maroon drops on the sweep board and vertical is working perfectly :banana: sized up perfect and easily, locks in perfect with a wide range.

The horizontal has a lot left to be desired. it can be centered, but with controls at almost their max.

I am contemplating going though and getting the rest of the orange/maroon drops on all the other boards and re stuffing them 3 electro cans.. what's your option Tom on that doing that? My largest fear is putting the set out of alignment by changing out all them caps.

Hint: any circuit that is "tuned" for correct operation will have an adjustable component, like a coil or potentiometer. If the fixed-value caps are way out of tolerance, the circuit is already detuned, and the best thing is to replace these and retune the circuit.

Note that the small ceramic or mica caps that tune the IF or tuner are seldom bad, compared to the larger paper or film caps or electrolytics in sweep circuits, etc., so it's not a good idea to blanket replace those small ones that tune IF or RF circuits. IF re-alignment is a chore, so if it's not broke, don't fix it.

But the paper or wax caps or electrolytics that affect sweep operation or are B+ bypasses, or large cathode bypasses (like the video output) etc. are worth replacing when things don't work right. The retuning then consists of adjusting the sweep size and linearity, for example, which will work much better if the fixed resistors and caps are within tolerance.

This did the trick Tom! I went ahead and replaced all the orange/maroon drops on the sweep board and vertical is working perfectly :banana: sized up perfect and easily, locks in perfect with a wide range.

The horizontal has a lot left to be desired. it can be centered, but with controls at almost their max.

I am contemplating going though and getting the rest of the orange/maroon drops on all the other boards and re stuffing them 3 electro cans.. what's your option Tom on that doing that? My largest fear is putting the set out of alignment by changing out all them caps.

If a stage is not operating well changing the drop caps and lytics is completely advisable. If any lytics get warm in operation (even if it takes better than 30min to get there) replacement is more than optional, it is necessary.

The CTC-16 I did I have limited memory of (it was a fast resto), but on my Silvertone CTC-15 clone (though it might have been old enough for the chassis to be RCA made*) I went slow and learned much...That set worked okay with the maroon drops in it, but many stages especially the color demod/video board benefitted greatly from the replacement of all the maroon drops. If performance seems lacking change those caps. One thing to note with most drop caps most were either plastic film or plastic/paper hybrid dielectric...They may very rarely leak current, but the early hybrid caps have degradation of the paper that will drift the tolerance of the capacitance value well out of tolerance...Most will still pass signal, filter, bypass, create a time constant (or whatever their specific job was) in a passable manner, but will be collctively far enough off optimum to notice.

*Pre 1963 nearly every chassis that was an RCA design used in a smaller brand was RCA made, then sometime in 63 RCA stopped selling chassis to other brands and those brands either built RCA chassis under license or designed their own chassis (some made clones for a while then switched to their own designs).

I rambled too much didn't I...

If a stage is not operating well changing the drop caps and lytics is completely advisable. If any lytics get warm in operation (even if it takes better than 30min to get there) replacement is more than optional, it is necessary.

The CTC-16 I did I have limited memory of (it was a fast resto), but on my Silvertone CTC-15 clone (though it might have been old enough for the chassis to be RCA made*) I went slow and learned much...That set worked okay with the maroon drops in it, but many stages especially the color demod/video board benefitted greatly from the replacement of all the maroon drops. If performance seems lacking change those caps. One thing to note with most drop caps most were either plastic film or plastic/paper hybrid dielectric...They may very rarely leak current, but the early hybrid caps have degradation of the paper that will drift the tolerance of the capacitance value well out of tolerance...Most will still pass signal, filter, bypass, create a time constant (or whatever their specific job was) in a passable manner, but will be collctively far enough off optimum to notice.

*Pre 1963 nearly every chassis that was an RCA design used in a smaller brand was RCA made, then sometime in 63 RCA stopped selling chassis to other brands and those brands either built RCA chassis under license or designed their own chassis (some made clones for a while then switched to their own designs).

I rambled too much didn't I...

Not at all! : D I sure love hearing and learning about all about this stuff :thmbsp:

I will check on the cans and see if they get warm at all. Probably get the drops changed out and check on that horizontal

Update,

Got the set working and looking better so far. I got some practice in doing purity and convergence setups and that was pretty cool :D and its looking pretty good. though not quite where it needs to be.

HV output was 16kv at about 175ma. I was able to bring that up to 24kv, that brought me up to around 210ma, I was able to get that down to around 200ma

Some fields on convergence can get sorta close with their pots at max, so I am going to check out some resistors and see if anything is outta range.

I noticed the sharpness/focus adjust does not have any effect. it looks like that coil has had work done in the past. so gotta figure that out as well, its a little off.

One of the 3 metal electro cans started getting warm after running a while, guess I know what I am going to be doing about that hehe

However something that kinda has me wondering what is up and I am not sure if I want to run the set more until I know what is going on,
about 4 hours of running as I was working on the set I started getting a hiss like sound coming from high voltage area. Letting the set sit overnight and firing it up this morning, did not have that hiss sound until about 15 minutes of running and then it returned. Any ideas what that is about?

And I got a picture of my first time doing a purity and convergence setup!

Update,

Got the set working and looking better so far. I got some practice in doing purity and convergence setups and that was pretty cool :D and its looking pretty good. though not quite where it needs to be.

HV output was 16kv at about 175ma. I was able to bring that up to 24kv, that brought me up to around 210ma, I was able to get that down to around 200ma

Some fields on convergence can get sorta close with their pots at max, so I am going to check out some resistors and see if anything is outta range.

I noticed the sharpness/focus adjust does not have any effect. it looks like that coil has had work done in the past. so gotta figure that out as well, its a little off.

One of the 3 metal electro cans started getting warm after running a while, guess I know what I am going to be doing about that hehe

However something that kinda has me wondering what is up and I am not sure if I want to run the set more until I know what is going on,
about 4 hours of running as I was working on the set I started getting a hiss like sound coming from high voltage area. Letting the set sit overnight and firing it up this morning, did not have that hiss sound until about 15 minutes of running and then it returned. Any ideas what that is about?

And I got a picture of my first time doing a purity and convergence setup!

I can't cout how many times I have done the convergence and purity dance. if i had to say, it's in the 100s :p:huge:

Dynamic convergence tip: if the board is fine but it is pretty far off at all pot settings try moving the convergence yoke as much as 1/4" forward or rearward of it's designed position (over the end flare of the electron gun/or red dag ring if the gun is hidden). Sometimes The dynamic field overall is too strong or too weak and moving it fore/aft can act as a mechanical gain control. If the outer 1-2" radius is kinda lousy but looks decent from 15-20' viewing distance you may have optimized it. Perfect convergence to the edges on a roundy is a rare achievement.

Some focus ideas: there should be a ~3-6KV ceramic cap on the focus coil that may not be holding correct capacitance value. IIRC the 16 is tube focus rectification...I tend to switch most focus rects to modern SS HV diodes. Removing the filament load relieves the flyback, and tube focus rects are not always as stable as I like.

If you can get the HV cage open to look for arcing/corona that may help.

Dynamic convergence tip: if the board is fine but it is pretty far off at all pot settings try moving the convergence yoke as much as 1/4" forward or rearward of it's designed position (over the end flare of the electron gun/or red dag ring if the gun is hidden). Sometimes The dynamic field overall is too strong or too weak and moving it fore/aft can act as a mechanical gain control. If the outer 1-2" radius is kinda lousy but looks decent from 15-20' viewing distance you may have optimized it. Perfect convergence to the edges on a roundy is a rare achievement.

Some focus ideas: there should be a ~3-6KV ceramic cap on the focus coil that may not be holding correct capacitance value. IIRC the 16 is tube focus rectification...I tend to switch most focus rects to modern SS HV diodes. Removing the filament load relieves the flyback, and tube focus rects are not always as stable as I like.

If you can get the HV cage open to look for arcing/corona that may help.

They did once make solid state sub for the HV rec (NTE508) if you could find one, would using one also lessen the load on the FB? ans what would one replace the focus rect (2AV2) with?

They did once make solid state sub for the HV rec (NTE508) if you could find one, would using one also lessen the load on the FB? and what would one replace the focus rect (2AV2) with?

This should work: https://www.mouser.com/ProductDetail/Rectron/R5000F-T?qs=sGAEpiMZZMtbRapU8LlZDya7%252By8IODRo7ob59eZhX AY%3D

I have 4 in series for the focus rect in my CTC2B...Granted that set uses three 3A2s for focus, HV rect, and HV doubling...Also the 3A2 has 18KV PIV rating so putting 4 5KV PIV rated diodes in series for a combined 20KV was cheap insurance against someone swapping the tubes around. (I also built a second one that I've been using in one of the HV positions in that set).

Before I looked up these modern diodes up I had a few selenium focus rect sticks from CTC-15 and similar sets that I used to eliminate the tube focus rect in a Zenith roundy and some other sets.

It will definitely reduce flyback loading since the filament of the focus rect tube pulls its filament power from the energy in the flyback

I can't cout how many times I have done the convergence and purity dance. if i had to say, it's in the 100s :p:huge:

Thats crazy huge!


Dynamic convergence tip: if the board is fine but it is pretty far off at all pot settings try moving the convergence yoke as much as 1/4" forward or rearward of it's designed position (over the end flare of the electron gun/or red dag ring if the gun is hidden). Sometimes The dynamic field overall is too strong or too weak and moving it fore/aft can act as a mechanical gain control. If the outer 1-2" radius is kinda lousy but looks decent from 15-20' viewing distance you may have optimized it. Perfect convergence to the edges on a roundy is a rare achievement.

Some focus ideas: there should be a ~3-6KV ceramic cap on the focus coil that may not be holding correct capacitance value. IIRC the 16 is tube focus rectification...I tend to switch most focus rects to modern SS HV diodes. Removing the filament load relieves the flyback, and tube focus rects are not always as stable as I like.

If you can get the HV cage open to look for arcing/corona that may help.

Ah! that's awesome to know! I may have to check that out and see how that changes things. But yeah, there is a few spots on that very outer 1-2'' that is lousy. but you can't really tell when tuned into a broadcast and does look great from 10 feet back. its impressive the quality of the picture on these older sets!

Indeed you remember correctly, it does have a tube rectifier. And I am up for helping out that flyback. I did notice the ma's surge over 300 for a very brief moment when the tv is first turned on. How hard is that to do solid state conversion?

I am not sure what I am looking for on the arching/corona. Do I need to do that check when the tv is running? I did notice that there was a static build up on the lead coming from the top of the hv cage. I did attach a few pictures of the flyback as well. I have a hunch that I am going to doing that flyback surgery to remove the rubber and do a silicon coating. :scratch2:

why does it look like you have wax or something on the tip of your HV rect 3ca3.
should not be there, and how did it get there?

Thats crazy huge!




Ah! that's awesome to know! I may have to check that out and see how that changes things. But yeah, there is a few spots on that very outer 1-2'' that is lousy. but you can't really tell when tuned into a broadcast and does look great from 10 feet back. its impressive the quality of the picture on these older sets!

Indeed you remember correctly, it does have a tube rectifier. And I am up for helping out that flyback. I did notice the ma's surge over 300 for a very brief moment when the tv is first turned on. How hard is that to do solid state conversion?

I am not sure what I am looking for on the arching/corona. Do I need to do that check when the tv is running? I did notice that there was a static build up on the lead coming from the top of the hv cage. I did attach a few pictures of the flyback as well. I have a hunch that I am going to doing that flyback surgery to remove the rubber and do a silicon coating. :scratch2:

Moving the yoke is for when things are badly out of range...Most procedures have you do the RG horiz and vert lines top and bottom first. I recently did a set where those would barely converge. The controls could barely achieve symmetrical mis-convergence (which consisted of bad mis-convergence over ~2/3 of the screen) moving the convergence yoke a bit got it to where I could converge it perfect to within 1" of the edge.

The SS upgrade consists of unplugging the tube, connecting a HV diode across the solder lugs on the underside of the socket banded end to cathode pin other end to plate pin...If you have a rect tube with an open heater you could put it in the socket for appearance. Putting two SS diodes in series for higher PIV tolerance may be advisable move...IIRC the upper focus voltage on some roundys is partway between 4 and 5KV so a single 5KV PIV rated diode may not have enough headroom. This probably will only knock less than 5mA off of H output cathode current.

In a dim or dark room with the HV cage open look for blue or purple glow inside the HV cage with the set running...The 16 and later RCAs did not make doing this easy with the way they mounted the rect into the lid.

why does it look like you have wax or something on the tip of your HV rect 3ca3.
should not be there, and how did it get there?

Yeah it does look like wax or something like that, it's always been there since I got this set and I haven't had a set like this before so I had no idea and guessed that it was supposed to be there, maybe as a conductor or something. So I clean that out?

Moving the yoke is for when things are badly out of range...Most procedures have you do the RG horiz and vert lines top and bottom first. I recently did a set where those would barely converge. The controls could barely achieve symmetrical mis-convergence (which consisted of bad mis-convergence over ~2/3 of the screen) moving the convergence yoke a bit got it to where I could converge it perfect to within 1" of the edge.

The SS upgrade consists of unplugging the tube, connecting a HV diode across the solder lugs on the underside of the socket banded end to cathode pin other end to plate pin...If you have a rect tube with an open heater you could put it in the socket for appearance. Putting two SS diodes in series for higher PIV tolerance may be advisable move...IIRC the upper focus voltage on some roundys is partway between 4 and 5KV so a single 5KV PIV rated diode may not have enough headroom. This probably will only knock less than 5mA off of H output cathode current.

In a dim or dark room with the HV cage open look for blue or purple glow inside the HV cage with the set running...The 16 and later RCAs did not make doing this easy with the way they mounted the rect into the lid.

Thanks for all the help so far Tom! I sure appreciate it : )

Thats some helpful info on the yoke. This is my first color set I've ever played with. But it's really awesome and I've really enjoyed learning and fixing this set.

The solid state upgrade seems pretty easy to do. I could always clip the heater pins on the tube afterwards? I would like to keep it in for looks.

Yeah I was thinking it would be hard to have that open with the way that tube is mounted, then it just dawned on me that I drilled some holes in the top of the cage, so I should be able to see in there. I will fire up the set for another run this evening before I pull the chassis again and see if I see anything going on in there. Could that wax stuff in the top of the fly where the tube plugs into it cause the corona? And I wonder if having the HV turned down can prevent that, I wonder why the HV was turned down low.

yes, it should be as clean as you can get it.
it's the connection between the FB and the RECT tube
https://imgur.com/xNgchz5 mine
very clean, save for a slight carbon arc point where i did not have the cage closed far enough

One thing to note about HV arcing and corona, if its happening BEFORE the HV rect, one tends to hear the 15k osc sound in it , if after, it has a more static type sound.
but this is rather general...

One thing to note about HV arcing and corona, if its happening BEFORE the HV rect, one tends to hear the 15k osc sound in it , if after, it has a more static type sound.
but this is rather general...

Wow that is a lot cleaner! I will try cleaning that up before my next run this afternoon. Maybe that will clear up the corona.

Thanks for the tip on that : D it's hard to recall now, but I want to say it sounded more like static. I will try to grab a video of it later this afternoon. Perhaps a before and after even.

Any idea if corona is really bad for the fly? I sure hate to ruin it

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

on this he fixes a flyback and draws a AC arc, though you rally cant hear it fully, you can SORT of hear the 15khz whine when he does.

A DC discharge is mostly after the biggest cap in the TV is charged ( the CRT ) and something someplace is bleeding it off somewhere.

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

on this he fixes a flyback and draws a AC arc, though you rally cant hear it fully, you can SORT of hear the 15khz whine when he does.

A DC discharge is mostly after the biggest cap in the TV is charged ( the CRT ) and something someplace is bleeding it off somewhere.

Ah! So I got a problem somewhere causing this happen to the flyback, may not be be a problem with the fly then?

Ah! So I got a problem somewhere causing this happen to the flyback, may not be be a problem with the fly then?


what i mean is, if its an HV AC related problem, and has the 15khz sound, its likely FB arc related. but if its more static crackle, like noise its more likely to be DC related, which could even be a crt grounding issue.

Also with an AC arc you get an ozone smell most of the time.

as he said w/o being able to look inside with it running, its hard to tell what is going on.

what i mean is, if its an HV AC related problem, and has the 15khz sound, its likely FB arc related. but if its more static crackle, like noise its more likely to be DC related, which could even be a crt grounding issue.

Also with an AC arc you get an ozone smell most of the time.

as he said w/o being able to look inside with it running, its hard to tell what is going on.

Oh I see! Most interesting and cool to know! Thanks for explaining how everything works : ) I sure appreciate it Yamamaya!

I was able to check out that video, he has some cool videos. I'd say I was getting the noise he had when he hooked up the horizontal tube, not the noise when he jumped the Sparks with the screw driver. I do see the difference now.

It's almost dark here, so I am going to fire up the set before long and see what happens

I may have found it or one of them. Takes about 15 minutes for it to warm up before it starts.

Killed the lights, could not see any arching or light peaking into the holes on the HV cage. Then I saw a decent sized blue arch coming from that big plastic cap of the HV regulator tube behind the HV cage. Got a picture of it even. it seemed a bit loose, so I cleaned up the cap and got it to fit snug. I no longer see the blue arch. I can still hear some hiss, not near as bad. I can't seem to find it or see it. I believe I am smelling that ozone smell, boy it kinda stinks.

I did notice that a 6BK4-C was installed so I tried the RCA 6BK4-B that I happened to have on hand and has the correct base on it. No change on that end, but it does glow a pretty cool green! Never seen a tube glow green before O.o

It's a bit late today for me so I am going to call it a night. Tomorrow I am going to look in the HV cage and take a closer look at that flyback and see if I can see anything, clean up that wax stuff on the top of that fb and see if I can figure a way to run this thing with that cage door open.

un related but interesting as I've been monitoring the current draw and when first turn on and its cold it hits about 320ma for a split second before it settles in around 197-201ma

I may have found it or one of them. Takes about 15 minutes for it to warm up before it starts.

Killed the lights, could not see any arching or light peaking into the holes on the HV cage. Then I saw a decent sized blue arch coming from that big plastic cap of the HV regulator tube behind the HV cage. Got a picture of it even. it seemed a bit loose, so I cleaned up the cap and got it to fit snug. I no longer see the blue arch. I can still hear some hiss, not near as bad. I can't seem to find it or see it. I believe I am smelling that ozone smell, boy it kinda stinks.

I did notice that a 6BK4-C was installed so I tried the RCA 6BK4-B that I happened to have on hand and has the correct base on it. No change on that end, but it does glow a pretty cool green! Never seen a tube glow green before O.o

It's a bit late today for me so I am going to call it a night. Tomorrow I am going to look in the HV cage and take a closer look at that flyback and see if I can see anything, clean up that wax stuff on the top of that fb and see if I can figure a way to run this thing with that cage door open.

un related but interesting as I've been monitoring the current draw and when first turn on and its cold it hits about 320ma for a split second before it settles in around 197-201ma

6BK4C is a newer version with better voltage rating a radiation protection.
that "green glow" is x-ray radiation NOT SAFE, for long term exposure.

the wax in the top of the FB is a bit disturbing...
cant really understand how it can get in there.

"figure a way to run this thing with that cage door open. "
one COULD drill out the 2 rivets holding the socket assembly at the top, but then you would have to come up with a way to hold it in place with the tube in the correct position in the FB when testing... and WARNING,,, :eek:
Running like that is a grater x-ray hazard than peeking at the HV reg...

6BK4C is a newer version with better voltage rating a radiation protection.
that "green glow" is x-ray radiation NOT SAFE, for long term exposure.

the wax in the top of the FB is a bit disturbing...
cant really understand how it can get in there.

"figure a way to run this thing with that cage door open. "
one COULD drill out the 2 rivets holding the socket assembly at the top, but then you would have to come up with a way to hold it in place with the tube in the correct position in the FB when testing... and WARNING,,, :eek:
Running like that is a grater x-ray hazard than peeking at the HV reg...

Well I don't want to be x-rayed too much so I popped the -c version back in.

Took some time this morning to clean all that wax out out of that connector. I am worried about that as well.

Sound seems to be coming from the HV reg cap. It gets better or worse when it's rotated. But has not got as bad since I tightened up the connection. Could I have a bad cable/cap?

Well I don't want to be x-rayed too much so I popped the -c version back in.

Took some time this morning to clean all that wax out out of that connector. I am worried about that as well.

Sound seems to be coming from the HV reg cap. It gets better or worse when it's rotated. But has not got as bad since I tightened up the connection. Could I have a bad cable/cap?


could be,,,
once they start to get carbon on them, it's hard to stop it.

I lost the cap to my horz output, and had to rig something, not as critical at the reg, they do have caps you can buy, but I'm not sure what size to get.

could be,,,
once they start to get carbon on them, it's hard to stop it.

I lost the cap to my horz output, and had to rig something, not as critical at the reg, they do have caps you can buy, but I'm not sure what size to get.

Well shoot.. I was hoping I could clean or fix my current one.
That cable gave me a good shock when I got close to it near the top of the HV cage. So I run my probe and it looks to pickup some discharge along that cable back to the HV cage.

If there is an obvious carbon track and it won't clean off you can drill out or grind the carbon track off and rebuild with silicone caulk...The HV rect bottom socket cups in some sets will arc through and carbonize and that is my typical solution to that...The silicone caulk has a higher dielectric strength than the average plastic they used back then so it at least in the case of carbonized holes is usually a sound solution...YMMV.

Well shoot.. I was hoping I could clean or fix my current one.
That cable gave me a good shock when I got close to it near the top of the HV cage. So I run my probe and it looks to pickup some discharge along that cable back to the HV cage.

being zapped by the CRT hv high voltage is graduation from greenhorn to veteran TV repair person. i cant count how many times i have had the joy of being hit by the reaming charge left in the CRT, it's one of the most exciting things about TV repair, is that you will Never know when you will be knocked on your ass by a hv discharge. anyway. if your cap on your reg has been arcing, then it has been most likely has carbon on it, and is hard to remove, but not impossible.

Some focus ideas: there should be a ~3-6KV ceramic cap on the focus coil that may not be holding correct capacitance value. IIRC the 16 is tube focus rectification...I tend to switch most focus rects to modern SS HV diodes. Removing the filament load relieves the flyback, and tube focus rects are not always as stable as I like.

If you can get the HV cage open to look for arcing/corona that may help.

I found it, its a 130m 6kv. I believe that is a 13pf. Closest I Found is a 12pf 6kv over at mousers

While I am over at mousers I can pickup them SS rectifiers. it is these ones correct? https://www.mouser.com/ProductDetail/Rectron/R5000F-T?qs=sGAEpiMZZMtbRapU8LlZDya7%252By8IODRo7ob59eZhX AY%3D

I also checked the resistor that is on the other side of that cap, its pretty far out of range. its suppose to be 47.5 meg and reads at 58 meg. I happen to have a 2 watt replacement I could use, however this thing looks pretty huge, a lot bigger than my 2 watt. Sams doesn't say the wattage to use for this.



If there is an obvious carbon track and it won't clean off you can drill out or grind the carbon track off and rebuild with silicone caulk...The HV rect bottom socket cups in some sets will arc through and carbonize and that is my typical solution to that...The silicone caulk has a higher dielectric strength than the average plastic they used back then so it at least in the case of carbonized holes is usually a sound solution...YMMV.

Well it sure can't hurt to give that a try, is there a particular silicone caulk that I should use? Same stuff to use on the flyback? I am thinking of doing the flyback as well.


being zapped by the CRT hv high voltage is graduation from greenhorn to veteran TV repair person. i cant count how many times i have had the joy of being hit by the reaming charge left in the CRT, it's one of the most exciting things about TV repair, is that you will Never know when you will be knocked on your ass by a hv discharge. anyway. if your cap on your reg has been arcing, then it has been most likely has carbon on it, and is hard to remove, but not impossible.

Whoot! I'm upgrading from greenhorn :banana: : D Ive been trying really hard not to get knocked on my ass. I only wish I could be half as good as y'all ; )
I am getting better though and may get there someday

The cap is pretty filthy with a black sooty substance, some of it has cleaned off but not at all of it. But I don't see a track or haven't found it yet

I found it, its a 130m 6kv. I believe that is a 13pf. Closest I Found is a 12pf 6kv over at mousers

While I am over at mousers I can pickup them SS rectifiers. it is these ones correct? https://www.mouser.com/ProductDetail/Rectron/R5000F-T?qs=sGAEpiMZZMtbRapU8LlZDya7%252By8IODRo7ob59eZhX AY%3D


Well it sure can't hurt to give that a try, is there a particular silicone caulk that I should use? Same stuff to use on the flyback? I am thinking of doing the flyback as well.


The cap is pretty filthy with a black sooty substance, some of it has cleaned off but not at all of it. But I don't see a track or haven't found it yet


May want to check the cap against it's listed value on the schematic before you order to be sure.

Those are the diodes. I'd order 2 and wire them in series for the focus rect...That way if anything arcs to the focus line it won't take out the diode as easily.

IIRC last time I did a fly doughnut the customer wanted me to use Permatex gray from the auto parts store...I recommend any 'sensor safe' silicone caulk (other types may contain acid that can corrode wires overtime).

Rubbing alcohol, glass cleaner and Goof off (a flamable liquid cleaner)are my go-to for HV cage cleaning. Goof off can dissolve plastics and some paints so I tend to reserve it for metal and as a nuclear option for some issues.

"Whoot! I'm upgrading from greenhorn : D Ive been trying really hard not to get knocked on my ass. I only wish I could be half as good as y'all ; )
I am getting better though and may get there someday "


Well, I got started very VERY young, being born with an innate ability to take things apart, and put them back together again... and have them STILL WORK! :)
Always had an strong aptitude for electronics, had my first soldering iron at age 10, was playing with old amps ( tube and SS ) in my teens, watched my dad fixing TVs growing up, surpassed his abilities at 15ish.
In my sophomore and Jr years of HS, I took the Electronics course they had ( which I terrorized :p )
It was there that they had all sorts of fun donated old electron goodies, and where I learned a lot of the stuff I still use today, ( and got zapped quite a few times ) AND... found out the hard way, that a picture tube really CAN implode when you least expect it.
It was from this class that I found and kept ( saved ) my CTC-16XL, along with other rare items like, a Zenith transoceanic royal 1000 , A Sansui 9090 & 1000, 2 dynakit mark iii amps. uher 22 hi fi special.
NOOO, I'm not a electronic pack-rat..

Before you try moving the convergence yoke, don't overlook the selenium rectifier block on the convergence board. As they age they start to break down. Usually just replace it with individual silicone diodes.

May want to check the cap against it's listed value on the schematic before you order to be sure.

Those are the diodes. I'd order 2 and wire them in series for the focus rect...That way if anything arcs to the focus line it won't take out the diode as easily.

IIRC last time I did a fly doughnut the customer wanted me to use Permatex gray from the auto parts store...I recommend any 'sensor safe' silicone caulk (other types may contain acid that can corrode wires overtime).

Rubbing alcohol, glass cleaner and Goof off (a flamable liquid cleaner)are my go-to for HV cage cleaning. Goof off can dissolve plastics and some paints so I tend to reserve it for metal and as a nuclear option for some issues.

Good call there Tom! I have not yet placed the order. I checked the schematic and its lists that cap at 130pf not 13.

https://flic.kr/p/RSgie4

Oh good, I wanted to make sure that was the silicon : D

Sadly I already found out that goo off can dissolve plastic a little while back : /

"Whoot! I'm upgrading from greenhorn : D Ive been trying really hard not to get knocked on my ass. I only wish I could be half as good as y'all ; )
I am getting better though and may get there someday "


Well, I got started very VERY young, being born with an innate ability to take things apart, and put them back together again... and have them STILL WORK! :)
Always had an strong aptitude for electronics, had my first soldering iron at age 10, was playing with old amps ( tube and SS ) in my teens, watched my dad fixing TVs growing up, surpassed his abilities at 15ish.
In my sophomore and Jr years of HS, I took the Electronics course they had ( which I terrorized :p )
It was there that they had all sorts of fun donated old electron goodies, and where I learned a lot of the stuff I still use today, ( and got zapped quite a few times ) AND... found out the hard way, that a picture tube really CAN implode when you least expect it.
It was from this class that I found and kept ( saved ) my CTC-16XL, along with other rare items like, a Zenith transoceanic royal 1000 , A Sansui 9090 & 1000, 2 dynakit mark iii amps. uher 22 hi fi special.
NOOO, I'm not a electronic pack-rat..

Oh wow! that's amazing! what's crazy is I sorta had a similar start in my young years. I got my first soldering gun at 12 though and I would often fix things like vcr's of my parents friends and such.

Then I sadly took a different path, my 10th grade art teacher thrown me up to a locker and said I was a worthless pos and I should drop out of school. Sadly I took his advice and I've always regretted that, ive felt like I have always had more potential. I have never had any kind of schooling or the such, just kinda learned things as I go.
I also got into computers very early, so I spent a good deal of my life working on computers and the such. And then every now and then poke at my vintage tv/radio stuff.

Back In my late teen years I ran across an old RCA tv from 1949 that was in a barn. I paid 10 bucks for it and took it home. That got me started in tube electronics. I got very lucky, I didn't know any better but the first thing I did was plug that tv in and turn it on. It didn't blow up, thankfully, but I actually got sound, but no picture. I replaced all the paper/wax caps. didn't do any resistors. and it worked, worked really really good. it always surprises everyone the great picture that tv has. I have hauled that TV around for 15+ years now. although its not a daily driver, it does get turned on a used. and all these years its never stopped working, much to my surprise. that is until not all that long ago. I was watching it and the crisp picture faded away to a blank raster : / I pulled the chassis to check out what I done all them years ago as I can't really remember and was a little afraid to see a crappy job or something, lol. but I am kinda proud of my younger self, I did a pretty darn good job. I pulled most all caps I replaced and did little splicing. I did find a 2 papers I didn't replace, probably didn't have them or something, I don't know why I didn't lol. But that didn't fixed the problem. so I pulled out the tube tester to test all them 29 tubes and would ya know one of the tubes went out. replaced the tube and boom, back to running good again. lol I should have checked the tubes before pulling the chassis. but I was really curious to see under it, its been so many years. lol

I also have 2 zenith radio tube sets from the 40's, a table top and a console. 7s633 and 8s563 man I love them radios : D and a sears silvertone a friend gifted to me. I am not quite the packrat, but I do have a fascination for these old tube electronics. I also have another RCA TV 21-D-7479 set a friend gifted me, but the chassis is rusted way beyond saving, I think, just crumbles when you touch it. though I have been thinking of seeing if I can bring life into again anyways, can't hurt to try right ; ) the picture tube tests ok-ish and there is a deal of wax under the flyback, maybe why it got put out of service. but I actually have a spare new in the box fly for that thing. Oh, I also picked up a Philco 12'' set 50t-1403. hmmm maybe I do have a problem. lol

This color tv though, its worlds more involved!

Oh man, now I'm rambling on lol

Before you try moving the convergence yoke, don't overlook the selenium rectifier block on the convergence board. As they age they start to break down. Usually just replace it with individual silicone diodes.

Hey Bill! Thanks, I didn't even think of that. I think ive read something somewhere a while back that its good idea to replace selenium rectifiers. I will look into doing that as well and see what happens.

Oh wow! that's amazing! what's crazy is I sorta had a similar start in my young years. I got my first soldering gun at 12 though and I would often fix things like vcr's of my parents friends and such.

Then I sadly took a different path, my 10th grade art teacher thrown me up to a locker and said I was a worthless pos and I should drop out of school. Sadly I took his advice and I've always regretted that, ive felt like I have always had more potential. I have never had any kind of schooling or the such, just kinda learned things as I go.
I also got into computers very early, so I spent a good deal of my life working on computers and the such. And then every now and then poke at my vintage tv/radio stuff.

Back In my late teen years I ran across an old RCA tv from 1949 that was in a barn. I paid 10 bucks for it and took it home. That got me started in tube electronics. I got very lucky, I didn't know any better but the first thing I did was plug that tv in and turn it on. It didn't blow up, thankfully, but I actually got sound, but no picture. I replaced all the paper/wax caps. didn't do any resistors. and it worked, worked really really good. it always surprises everyone the great picture that tv has. I have hauled that TV around for 15+ years now. although its not a daily driver, it does get turned on a used. and all these years its never stopped working, much to my surprise. that is until not all that long ago. I was watching it and the crisp picture faded away to a blank raster : / I pulled the chassis to check out what I done all them years ago as I can't really remember and was a little afraid to see a crappy job or something, lol. but I am kinda proud of my younger self, I did a pretty darn good job. I pulled most all caps I replaced and did little splicing. I did find a 2 papers I didn't replace, probably didn't have them or something, I don't know why I didn't lol. But that didn't fixed the problem. so I pulled out the tube tester to test all them 29 tubes and would ya know one of the tubes went out. replaced the tube and boom, back to running good again. lol I should have checked the tubes before pulling the chassis. but I was really curious to see under it, its been so many years. lol

I also have 2 zenith radio tube sets from the 40's, a table top and a console. 7s633 and 8s563 man I love them radios : D and a sears silvertone a friend gifted to me. I am not quite the packrat, but I do have a fascination for these old tube electronics. I also have another RCA TV 21-D-7479 set a friend gifted me, but the chassis is rusted way beyond saving, I think, just crumbles when you touch it. though I have been thinking of seeing if I can bring life into again anyways, can't hurt to try right ; ) the picture tube tests ok-ish and there is a deal of wax under the flyback, maybe why it got put out of service. but I actually have a spare new in the box fly for that thing. Oh, I also picked up a Philco 12'' set 50t-1403. hmmm maybe I do have a problem. lol

This color tv though, its worlds more involved!

Oh man, now I'm rambling on lol

That teacher was probably projecting his problems onto you...The title art teacher should disqualify him from making any statements about any academic matters, and give you an indication of how far he has fallen from any life aspirations he had in his younger years. Its too bad your parents weren't like mine, they'd have told you the same then went to school and read that schlub the riot act bad enough that he'd be scared of ya. :D

That teacher was probably projecting his problems onto you...The title art teacher should disqualify him from making any statements about any academic matters, and give you an indication of how far he has fallen from any life aspirations he had in his younger years. Its too bad your parents weren't like mine, they'd have told you the same then went to school and read that schlub the riot act bad enough that he'd be scared of ya. :D

hehe yeah too bad they didn't, that would have been great! him afraid of me instead of me of him :D Too bad I didn't see things differently back then as I do now. But I'm thankful, ive come pretty far on my own : )

Progress update,

New 6kv cap arrived so I thought about getting that knocked out. Got it pulled out and it was 3 times out of range on just my multimeter. While having that out, I also pulled that 4.7 meg that was at 6 meg that was connected to it to replace it as well. connected up with this 6kv cap is a 6kv 66 meg crazy looking resistor. It reads completely open O.o I was not sure if there was a special way to test such a resistor, but I would figure a resistor is a resistor right? I should get 66 meg give or take. So if that is bad where about do I even get a resistor of that size? I could not find one on mousers.

Next, I don't how I missed this when I looked over everything under the chassis and cleaned up the controls, but the Service/Normal switch is burnt to a crisp O.o and is even missing part of its wafer and 3 of the 4 connection points broke away from the switch. Not sure what would cause that switch to burn up like that.. Anyone have an idea where I could pick up a replacement switch?

Why do i have the sudden urge to say " I am Groot" :p

Why do i have the sudden urge to say " I am Groot" :p

That's awesome! : D

That's awesome! : D

I tend to take my inspiration from something about a decade sooner :) Darkstalkers!

I tend to take my inspiration from something about a decade sooner :) Darkstalkers!

Cool :)

Progress update,

New 6kv cap arrived so I thought about getting that knocked out. Got it pulled out and it was 3 times out of range on just my multimeter. While having that out, I also pulled that 4.7 meg that was at 6 meg that was connected to it to replace it as well. connected up with this 6kv cap is a 6kv 66 meg crazy looking resistor. It reads completely open O.o I was not sure if there was a special way to test such a resistor, but I would figure a resistor is a resistor right? I should get 66 meg give or take. So if that is bad where about do I even get a resistor of that size? I could not find one on mousers.

Next, I don't how I missed this when I looked over everything under the chassis and cleaned up the controls, but the Service/Normal switch is burnt to a crisp O.o and is even missing part of its wafer and 3 of the 4 connection points broke away from the switch. Not sure what would cause that switch to burn up like that.. Anyone have an idea where I could pick up a replacement switch?

Most DMMs don't measure as high as 66M and indicate open on anything 1 ohm above whatever their max range is. Odds are it is still okay. If it is actually bad you can take a few xxM ohm resistors of lower value and make a 66M resistor (resistances in series add)...I did something like that on my 21CT55 about 6 months ago.

Most DMMs don't measure as high as 66M and indicate open on anything 1 ohm above whatever their max range is. Odds are it is still okay. If it is actually bad you can take a few xxM ohm resistors of lower value and make a 66M resistor (resistances in series add)...I did something like that on my 21CT55 about 6 months ago.

Thats cool, I will leave it be for now until I have a way to properly measure it. I will get the other parts replaced and see how the focus control works.

Update;

Its looking pretty good, not quite perfect yet and still got work to do until I am fully happy. I still have not found what has the horizontal centering pot control out of alignment. Also the focus control still does not work after replacing the 130pf and 4.7m resistor. I wonder if the pot is any good or if its something else causing a problem. But it isn't too far off from where it needs to be.

Moving the convergence coil up to that mark on the neck of the picture tube did the trick! and the convergence pot controls work much better.

I also can't do the grey/white setup until the replacement service/normal switch shows up and I figure out how to undo and fix that mess. Its a bit off from when I cleaned the pot controls, but it isn't terrible.

Thought id give it run for a few weeks and see how everything ive done so far holds up and works. Got everything put back together and move it up to the living room. I then thought maybe I may pull that back cover back off so it can run cooler.. :scratch2: but its nice having the original back on it.

I am surprised how close the colors are to my flat panel and how nice the picture is on this set, though its not perfect yet. even the audio is pretty darn good. I really love this TV set.

Nice!

Call me a worry wart, but it always bothers me to have the back off a set off when it's on a wall with a picture hanging above.

The original backs give plenty of ventilation. What I'd do is drill a few holes in the base of the HV cage and a install a fan at the too to draw hot air out. If you're really worried about too much hot air in the cabinet hook a fan to the top inside of the back blowing out.

You can bust the CRT neck way too easily without the back on.

The original backs give plenty of ventilation. What I'd do is drill a few holes in the base of the HV cage and a install a fan at the too to draw hot air out. If you're really worried about too much hot air in the cabinet hook a fan to the top inside of the back blowing out.

You can bust the CRT neck way too easily without the back on.

I'm thinking of doing that to mine, once everything is all done, but I can't decide on an ac or a dc fan, would brushless dc fan be OK with all the RFI and xrays in that cage? or would AC be better?

Either would probably be okay. My 21CT55 has an old 12V computer fan (straight from my PC junk bin), running off 6Vdc of rectified, filtered heater voltage.

It is only rated to draw about as much current as a 12AX7 running at 12V so at 6 it should draw around half that. At 6V a noisy high flow 12V case fan runs quiet and moves plenty of air for a small HV cage.

Great points! Id sure hate for that picture to fall off the wall and hit the neck of my picture tube! I was feeling a lot of heat coming from the back of this set last night after about 4 hours of running.

I did drill holes in the top of the HV cage as well as 2 bigger holes in the bottom of the HV cage.

I have not yet installed a fan but have been thinking of the best way to do that. And some great ideas posted here.

Tom, did you do that fan inside of your HV cage? I know they make some smaller sized computer fans that I probably get to fit into that cage. What do you think of pulling off the heater power from focus tube, the connections are right there inside of the HV cage? I even thought about placing a normal sized PC fan under the chassis blowing up under the HV cage drawing in cool fresh air from below.

Also, so far it seems that sanding that HV reg cap down with some fine grit paper and covering it with that silicon, so far seems to have stopped the leakage. not sure how long that fix is going to last. I have been occasionally turning off the sound and listening for it.

I have noticed today that the convergence has drifted out a bit, I kinda figured maybe this would happen as the new parts break in? I will give it another good few days of working before realigning it again, maybe just wait till this weekend and bring it all back in.

Anyone got any suggestions on doing grey/white scale setup without having a usable service/normal switch? I have the RCA book that explains how to do purity, convergence and the grey/white black/white setups. and I can tell its off a bit and I had to eye the blue/green/red screen pot controls since I move them all out of adjustment when I hit them with contact cleaner and lube. I may just have to wait until I get the new switch and get it installed.

oh! I got about a total of 10+ hours so far on that 250ma fast blow fuse since I installed it so far with no problems : D

You can do minor gray scale tracking on a picture, but it's best if it's a still test pattern with a full range from black to white, like color bars. And it's really best to have the service switch. The problem is that the brightness control and G2 controls have similar effects on the picture, so it's hard to tell if they have been set in opposite compensating directions. The service switch puts a fixed bias on the tube so that when you adjust the G2's you are setting them for design center normal cathode and G1 voltages, and the video output tube has the fullest possible range available.

So, yes, you can tweak the G2 controls, but when you get the service switch fixed, you may find that all three are off by some amount.

If you want to play with it now (and maybe have to readjust later), the principle is to turn the color all the way down, set brightness to mid range, and make the blacks just black and colorless, and the dark grays also the same gray as the highlights, with the G2 controls. Then if all the shades of gray from black to white are off color (but are the same color, that is they are tracking), adjust the green and blue drive. You may have to go back and forth from drives to G2s a time or two.

It's the setting of brightness arbitrarily to midrange that may cause a discrepancy with the service switch procedure, but what the hey, if you want to try it, go ahead.

Tom, did you do that fan inside of your HV cage? I know they make some smaller sized computer fans that I probably get to fit into that cage. What do you think of pulling off the heater power from focus tube, the connections are right there inside of the HV cage? I even thought about placing a normal sized PC fan under the chassis blowing up under the HV cage drawing in cool fresh air from below.


Anyone got any suggestions on doing grey/white scale setup without having a usable service/normal switch? I have the RCA book that explains how to do purity, convergence and the grey/white black/white setups. and I can tell its off a bit and I had to eye the blue/green/red screen pot controls since I move them all out of adjustment when I hit them with contact cleaner and lube. I may just have to wait until I get the new switch and get it installed.

The customer's CTC16 I did I never installed a fan on the HV cage. Given HV arcing tendencies I would never install a fan on the inside of better than 95% of the sets I've seen... The CTC16 seems like an especially bad choice for an internal fan. I'd also strongly advise against powering the fan from a flyback winding... you will probably cause more extra current/heat in the flyback than the cooling the fan provides can balance....use the heater winding on the main 60Hz power transformer or a separate power supply for the fan (you could wire a wall wart in parallel with the main power transformer so the fan comes on with the TV power switch).

Blowing up from underneath is a valid approach. On my 21CT55 I glued a fan to a 3" PVC pipe section about 4" tall. The PVC sits on top of the cage over a factory vent hole that has a bulgy cover and extends that vent into a duct for the fan which pulls hot air out of the cage. I used the two power leads to tie down the fan/PVC assembly to the chassis so it won't be displaced in normal use.
You could pull a vertical yoke lead with brightness at min and adjust the screens or pull the vertical output tube... I've done it both ways in sets that lack a service switch by design.

lol if I would have thought about that fan in the HV cage for just a moment I would have realized how bad idea that would be :D as well as I have been thinking of going ss on that to lower the heater load to help the flyback..

well it can't hurt to get some practice setting up them grey scale settings. I will also try pulling the vertical tube as well and try it that way as well and get a feel for things.

The RCA book mentions flipping the kine bias switch and video peaking switch. I am curious the operation behind these switches and what they do?

You would change the kine bias setting if you can't get the correct result on one or more guns when adjusting G2. This should be part of the adjustment instructions.

Not sure what the peaking switch has to do with gray scale, would expect it to only affect picture sharpness.

lol if I would have thought about that fan in the HV cage for just a moment I would have realized how bad idea that would be :D as well as I have been thinking of going ss on that to lower the heater load to help the flyback..

well it can't hurt to get some practice setting up them grey scale settings. I will also try pulling the vertical tube as well and try it that way as well and get a feel for things.

The RCA book mentions flipping the kine bias switch and video peaking switch. I am curious the operation behind these switches and what they do?

no two CRTs are alike, nor do they STAY the same in their lifespan , I'm pretty sure those switches are there to adjust for subtle differences in CRT gun outputs , and to adjust for how they may change as the tube ages.

Most interesting, I noticed a big difference in flipping the video peaking switch. Seems to lower the brightness quite a lot. The kine bias switch made such a small difference it's was really hard to tell.

I'll have to read the book again this evening, but if I recall correctly, I believe it said to flip the switch if the furthest position from chassis. I remember wondering if they meant from top or bottom of chassis O.o i left the switch in it's position when I received this set with switches all the way down position.

I wonder if these switches effect gun output if that could effect the life of the crt if not set correctly?

Most interesting, I noticed a big difference in flipping the video peaking switch. Seems to lower the brightness quite a lot. The kine bias switch made such a small difference it's was really hard to tell.

I'll have to read the book again this evening, but if I recall correctly, I believe it said to flip the switch if the furthest position from chassis. I remember wondering if they meant from top or bottom of chassis O.o i left the switch in it's position when I received this set with switches all the way down position.

I wonder if these switches effect gun output if that could effect the life of the crt if not set correctly?

Kinne bias will absolutely affect life. It should be set to the dimmest position that will allow all 3 guns to produce lines during G2 set up.

Peaking not so much....it is basically a video trebble control. It changes the level of the high frequency portion of the video. Lead dress of the CRT socket wiring and differences in video chain tubes and alignment will affect high frequency video. Peaking is a compensation to allow fairly uniform video detail.

Curious that the peaking switch would affect brightness. I wonder if they did something weird, like reduce the video gain (contrast) at the extreme peaking setting so there was more headroom for high frequencies? If I have the time I will have to trace through the schematic to see what's going on.

Curious that the peaking switch would affect brightness. I wonder if they did something weird, like reduce the video gain (contrast) at the extreme peaking setting so there was more headroom for high frequencies? If I have the time I will have to trace through the schematic to see what's going on.


It's literally what Electronic M said, Video peaking switch is a “a video treble control” hung off the contrast pot, it creates the illusion of adjusting brightness by changing the contrast parameters by choosing one of 3 different capacitors , depending on where the switch is set.

Update,
Put in a some late nights re doing the purity and convergence as well as the black and white setups. All very good and helpful into! : D it was a lot of learning and work, but I got an amazing picture now! It is crazy how involved these TV's were and all you had to do. I love it! hehehe

After getting the vertical pulled and the grids turned down I was able to see a difference in the Kine bias switch. it was already in its lowest setting and where instructions called for on the setup. Plan on keeping it there to get more life out of the CRT.