Just got done staining the cabinet. Looks so much better than it was when I got it down in south Florida (Thanks again Tvcollector!) going to use some brushing shellac on it tomorrow and call this project pretty much done. Also, how much would a electronically restored and cosmetically restored ctc-7 pensbury with a good 21CYP22 sell for? I have no intentions of ever selling this set anyways just curious. Is a ctc-7 Pensbury a rare set?

Don't really know how "rare" they are, but I've only seen one in person, owned by a friend, and completely original. needs full restoration now, but performed well until last year. Very pretty fruit wood (? could be walnut, but light in color) cabinet, and a bright pic on original CRT.
I have an Anderson in blonde that I restored many years ago, and now need to do it again. Have a "tests new" 21CY ready to go.
Wishing you continued luck with your Pensbury! CTC-7s are good chassis, and will hold convergence due to the wire-wound pots IMO. :yes:
Kevin

Thanks Kevin also best of luck to you restoring your ctc-7 again!

Turned the set on today and it took a little less than 5 minutes to get full hold and great colors. Is it slowly fixing itself maybe?
If the problem comes and goes, You may need to re solder the grounds on the horz board. I should have mentioned this before but forgot. I did it on my set just to avoid a problem. Pointing at one so you can see what they look like.

Will do after I finish the cabinet.

OK swapping tube did help and I can get a somewhat stable lock but still it has to heat up for about 3 minutes.

OK here is the nearly finished set. The lacquering could have gone better but it looks great to me. Here is the set in operation. https://www.youtube.com/watch?v=4kSrHSV3mNQ&feature=youtu.be Do any color adjustments need to be made and should I adjust the dynamic convergence?

Looks great, I would not mess with it just enjoy :thmbsp:

I don't see a convergence issue, at least not one worth stressing yourself out over trying to fix.

If you wanna be a perfectionist the image still looks slightly tilted.

It sounds great, even through your camera's microphone.

Also, vertical video... ugh

That's what I like to hear! Thank you so so much Dave you are the best! :thmbsp: could have never done it without your help and all the other nice people here at VK. It has been A LOT of fun restoring this quality piece of American craftsmanship. Will wrap this project up once and for all tomorrow and use this set for years to come! If you ever have any b&w sets you don't have room for I will gladly take em off your hands.

I apologize for the vertical recording. I was stuck with my phone at that time. Will fix the slight tilt as I make the final step of this restoration. Horizontal is still a bit slow to kick in but I will head down to the tube store this week and buy a known good 6CG7 for the h oscillator.

Do any color adjustments need to be made and should I adjust the dynamic convergence?You're done. Don't mess with convergence or anything else. The colors are rich and the flesh tones (always a good test) look natural.

You can tell the convergence is good by watching white lettering that appears in the corners. If convergence was bad, the letter edges would have fringes of wrong colors instead of looking clear and sharp as in the center of the picture.

Congratulations on sticking with this project.

Enjoy!

Phil Nelson

Great work, young man! :yes:
Just a quick tip on leveling the yoke: Don't attempt to slide the yoke forward (or rearward). Its normal position is 1/4 to 3/8 inch shy of being fully seated against the CRT bell. This is the 'sweet spot' for best purity. It is integral to the factory setup procedure on roundies.*
-
*On rectangulars, it was 1/8 to 1/4 inch shy of being fully seated.

I believe you mentioned the h.osc tube (6CG7) is NOS. But it still could be borderline weak, causing the long lag to lock in.
Perhaps one of the kindly souls here could send you a known-good-in-H.osc-service 6CG7.
-
There's a 'quick & dirty' test that old techies used a lot in the field for this kinda problem.
Have the set warmed up and everything locked in. Turn the set off for about 7 seconds, and then back on. It should come on with the horiz fully locked in. If it comes on with lines and there's a delay to lock in, it's a sure sign the osc. tube is borderline.

If I try that on my CT-100, the horizontal comes up back in sync ...
but with horrendous ringing and distortion in the left part of the screen.
It stays that way forever, or at least a long as I dared leave it on
being afraid of some a meltdown in the flyback.

And it won't work right unless the set is left of for at least 10 minutes,
when it comes up perfectly normally.

I can't remember if I posted this info here but here it is again. RCA developed a fast warm up 6cg7 for their color and black and white tv's. It is a clear top tube, getters on the side. They are designed to warm up in 11 seconds, making sure horizontal drive and sync are waiting when the output tube starts conducting. The wrong type can result in a jump in cathode current at turn on or horizontal lines until the 6CG7 warms up. They are also very reliable but are getting a bit pricey because of audiophiles. It is very important to use this tube.

Would I be able to find one at the tube store (6CG7 special one)? And should I check the cathode current on the h out tube? Going to pull the chassis out today to do my final checks and finish anything that needs to be done.

Well I found a spare 6CG7 lying around (not the special one) and that one really is pretty much ready to go when the HV kicks in. Should I still invest in the fast heat up one?

If I try that on my CT-100, the horizontal comes up back in sync ...
but with horrendous ringing and distortion in the left part of the screen.
It stays that way forever, or at least a long as I dared leave it on

Is the ringing/distortion in the H sweep itself? Or in the video/video IF chain (does it vary with the contrast setting)?

Well I found a spare 6CG7 lying around (not the special one) and that one really is pretty much ready to go when the HV kicks in. Should I still invest in the fast heat up one?
No, not if it's working OK and coming on in sync. I have never had occasion to need the 'special' 6CG7, in 30+ years in the trade.

I would monitor the cathode current on the horizontal output tube from turn on to raster. If it does not rise high and settle down once high voltage comes up, I would not worry.
My CTC9C is very picky about the 6CG7.
Just a suggestion to prevent possible problems. Newer 6CG7 tubes probably have the rapid warmup feature. I have seen older ones that were very slow to warm up.

OK how exactly do I do this?

Ok checked the current and it went well above 210ma and when the HV kicked in it went past 2000ma. I am pretty sure I did this right. Here is what I did http://www.boxcarcabin.com/rcacathode.htm

What is the cathode current once the set settles down?

178ma after the set has sat for about 30 seconds.

OK cant get any raster because I dont think the 3A3 HV rectifier tube is doing its job. I cant pull an arc off the metal bell surrounding the 3A3 socket. The filaments on the 3A3 are still intact. I know the flyback is working because I can pull a spark off of the flyback cap. What is going on?

OK for sure it is something in the 3A3 socket causing the problem. Or does cathode current testing cause this?

OK resoldered pin 3 and everything is back to normal. But is 178ma OK for the cathode current though? Do any adjustments need to be made?

I think 178ma is fine, most of the 60s sets are usually around the 200 mark or below.. after 210 or 215, then it gets into the high range and will cook the flyback eventually.. Yours only spikes up for seconds upon turning on, and I think that's normal..

:sigh: Yet another issue. Put the chassis back in (which was hell) and now I am having signal problems. I'm getting the weird tuning beeps and squeals and everything is covered by a shade of green.

It worked beautifully not long ago. Look for obvious stuff first. Wiggle tubes, starting with the tuner and working forward along the signal chain through the IF section, and so on. Look for wires you might have knocked loose when removing or reinstalling the chassis, etc.

Phil Nelson

OK well the 6AW8A on the agc board is not even glowing I wiggled it around a bunch, still nothing tried swapping with a known good tube still nothing. Could I have broken the socket? And is that tube the reason for the bad signal and green tint to everything?

The boards on the RCA color run hot. If subbing the tube does not help, it may be the solder connections under the tube socket. If you do pull the chassis again, resolder the 6AQ5 vertical output socket pins. The 6AQ5 runs very hot and those connections can be troublesome. The strange thing is the 6AW8 is first video/AGC. I would think no picture if it is not lighting.

Going to clean the tuner and resolder the tube sockets. Let's hope this goes well!

Resoldered all the pins on the 6AW8A socket and checked for any visible damage still no filament glow checked the heater pin voltages with the dmm nothing at all.

You are going to have to trace the circuit foils and see where you are losing the 6 volts AC. Look at the grounds on the board. They can cause trouble.

Cant seem to trace it. The foils arent actually traced to another lead it is just a dot of solder. Should I just put in a new socket?

Cant seem to trace it. The foils arent actually traced to another lead it is just a dot of solder. Should I just put in a new socket?

Check the resistance between the top and bottom of the socket. If it checks open replace socket. If it tests like a wire then you are going to have to try harder to trace it since it ain't the socket if you have continuity.

Keep in mind that if you don't have 6.3VAC at the socket solder pads it won't work even if you change the socket. Also if one of the heater pads is supposed to be grounded and the trace or ground lug is bad that will kill your heaters too.

OK resistance is good on all pins so just going to have to see what the problem is. I did notice that on the other socket next to the problem socket the middle ground lug is there but on the problem socket it looks like it never had that middle ground lug even though a trace hole is there but has a thin layer of solder over it. Would this raise any red flags?

OK here's a simplified sketch from the CTC-7 schematic.
There's a second tube on that board, a 12BY7. Is it lighting? (Assuming it is.) It'll have 6V on pins 4 and 5, which are tied together, with the center tap (pin 6) grounded.
There should be a long trace (or possibly a wire topside of the board) going over to the 6AW8, carrying 6V to pin 4. If 6V is absent, look for an open somewhere on that line.
-
If there is 6V on both pins 4 and 5, look for an open ground offa pin 5.

Hmm that is puzzling, I could have sworn I pulled another 6AW8A out of the 12BY7A socket. Could that have caused the loss of filament on the 6AW8A in the other socket? Then again, I'm pretty sure that there was always a 6AW8A in the 12BY7A socket and I know that at one point the problem tube did glow. Will go and pick up a 12BY7A today just in case and do some investigating on that board.

Was able to dig up a 12BY7A. The 12BY7 glows but still no 6AW8A glowing. Will investigate more later today like I said.

If the 12BY7 is lighting, 6.3 is getting to the board. Check pin 4 of the 12BY7 to pin 4 of the 6AW8 for voltage. It should have none. If you get voltage look carefully for a bad connection or break in the foil.
Look very carefully at the solder on the pins of the 6AW8 tube socket.

Here's the full manual if you don't already have it. The schematic is 'waay down at the bottom..
http://antiqueradio.org/art/RCACTC-7TelevisionFactoryManual.pdf

This just keeps getting weirder and weirder. From pin 4 of the 6AW8A to pin 4 trace on the 12BY7A I measure continuity. This makes no sense. How am I getting no filament when the trace carrying the filament is fine? And the grounds are good too. Also I get 5.6 volts on pins 4 and 5 on the 6AW8A socket. Was 1.6v between 12BY7A pin 4 and 6AW8A pin 4 for about 3 seconds then it settled down to 0v. What is going on? :scratch2: Also note there seems to be a wire bridging pin 4 of the 12BY7A to pin 4 on the 6AW8A although the trace that connects the two pins have continuity.

...I get 5.6 volts on pins 4 and 5 on the 6AW8A socket.
Are you saying there's 5.6V on both pins 4 and 5 with respect to ground?
If so, pull the tube. Now there should be zero volts on pin 5.
With the tube still removed, check continuity from pin 5 to ground. It should read zero resistance, solid continuity. If it's open, there's your problem.
-
Or are you saying there's 5.6V between pins 4 and 5? If so, that's what you should be getting. This would indicate one of the lugs is open inside the socket.
-
(For convenience I'm using your 5.6V measurement in lieu of the called-for 6V.)

well just put in a new wire jumping pin 4 to the other pin 4 and that fixed it. Not sure why it would have mattered but I fixed it and cleaned the tuner. Now to put it back in the cabinet. Fingers crossed for good results! :D

delete

OK got it back in the cabinet tuner is crystal clear but now I dont have full vertical height and there is a vertical fold on the top of the vertical hold. The fold is about maybe 2 inches. I dont know what is happening now. I replaced the 6AQ5A tube but still no luck :(

Alright was able to fix the vertical folding problem. But now I cant get any color!:dammit: What now?

what was wrong with the vert? convergence board not plugged in?

wiggle color osc tube, make sure all tubes lighting in color section, adj fine tune.

I wonder if you have one or more funky sockets on the boards. That is suggested by an old jumper to a socket pin. Sometimes resoldering pin connections on the sockets can help. Obviously, you want to be delicate with any work on those boards, to avoid lifting traces, etc.

I am curious how you fixed the vertical problem. Intermittency (fixed by wiggling tubes) also suggests bad socket-to-board connections, or simply a bad socket.

Sometimes you can improve sockets by cleaning the devil out of them or (carefully!) bending the metal inside the socket holes to make better connections.

Phil Nelson

Will go through and resolder all the sockets. And I forgot to mention Dave I did indeed forget to plug in the convergence board my bad. Only problem is my horizontal hold knob is stuck on the shaft. Will heat it up then pull the chassis out for hopefully the last time. Note I did lose color after cleaning the tuner. Could I have messed up something in the tuner causing no color? All I did was go over the copper coils and other moving parts with a q-tip dipped in deoxit.

Could I have messed up something in the tuner causing no color? All I did was go over the copper coils and other moving parts with a q-tip dipped in deoxit.
This likely caused osc drift, requiring re-adjustment the fine tuning. It'll probably require a couple more adjustments before it fully stabilizes. The copper coils are not what require cleaning, just the switch contacts.

Oh no, did I damage the copper coils in the process? And is the osc drift adjustments coil adjustments? Which coils exactly need to be adjusted if needed?

Nein! No! nyet!! Don't adjust any coils in the tuner! "Fine tuning" refers to the customer adjustment called Fine Tuning. The Deoxit does't damage anything. It can sometimes cause a bit of temporary osc drift until it's completey evaporated.

OK not touching any coils. You think the fine tuning adjustments should give me my color back? Because I have messed with the fine tuning knob and I can't get anything. Should I resolder the tube socket pins or just wait for the drift to go away?

You have nothing to lose by simply waiting a while. Remember, the TV worked wonderfully just a short time ago. I wouldn't resolder all of the tube sockets at this moment.

Phil Nelson

the coils in the tuner should not be touched, you can alter the tuning by collapsing or expanding them. Hopefully you did not change the shapes of the coils. No need to clean the tuner unless its noisy (snowy picture). When cleaning only the contacts need to be cleaned. Spraying is bad as it can get into places it should not be. Best bet is to leave it be for a few days and IF spray got somewhere it should not be it will dry out.

IF the fine tuning ring has no effect then there is prob something wrong with the mechanicals of it. fine tuning def effects the picture, generally it goes from black and white smeary to beat freq sound bars to loss of sync. see my video re fine tuning about how it should look.

https://www.youtube.com/watch?v=RAk9lKv03zA

Note your 7 may not have the range as demo above but you should still have a range that shows change.

Made sure to be extra delicate with the copper coils in the tuner did not bend them at all. And as for the fine tuning Dave it is all normal just no color it does everything your video says minus the color. Should I open the tuner back up and just wipe the deoxit off the copper coils with a q-tip? Or is waiting the best thing? Also on the bottom right corner there has always been a discoloration it was at first yellow but now is more a green color I tried doing a purity setup and moving the yoke but no luck and I have tried degaussing the set at least 5 or 6 times and still it won't go away.

no color at all means the color osc is prob not running that is if your fine tuning is working like in the video. leave it be for a day or two. wiggle the 6GH8 tube (color osc). perfect purity can be hard to obtain. often just turning the set 90 degrees will have a huge effect on the purity. from the early pics of it working I would say you are fine.

Well in my case the color osc is a 6U8A. Wiggled it, nothing. Replaced with another 6U8A, nothing. will let it sit till Monday evening and try it again.

OK lost my HV after I wiggled the 6DQ5 tube in its socket. Not sure why that messed it up but I reinserted the 6DQ5 still nothing tried wiggling it still nothing ran it without it nope. Made sure no pin connections were shorting themselves out. What now?

Fixed my HV loss. Guess I broke the ground wire on the cathode on the horizontal out tube. Gah! Still no color! just black and white! Note on the color bar test pattern I can just barely see the color in the color bars when I adjust the fine tuning. What is going on?

a few things..

are you running at reduced voltage? try it back at 120v if you are.

try adj the horz hold a little bit, not enough to lose sync just a little both ways.

is the pic clear or do you have snow?

try a different channel adj fine tune again.

what exactly did you work on AFTER you had the working picture.

wiggle tubes in chroma section.

are you sure you are getting color on the color bar generator or are you seeing rainbow pattern like a loss of sync?

Wiggled tubes. That didnt help. At first first I had no sign whatsoever of color. Then I replaced the 6U8A color osc and I got the faint color in the color bar pattern. I will go through and adjust the 3.58Mhz and other coils in the chroma section. I know what I am doing with the coils and I know not to adjust too far. Tried everything you said Dave but still nothing. Will report back after I adjusted the coils. No rainbow pattern at all either.

Eureka! Was able to get my color back! Going to wrap this whole project up hopefully later tonight. All I did was adjust T704 and L704. Will make a video to show it and see if it needs any work on the color.

Everything looks good except for the bottom right corner of the CRT. There is a green tint over everything in the bottom right corner. I've tried purity setup and deguassed the CRT multiple times and it won't go away. Is the shadow mask bent too much?

Everything looks good except for the bottom right corner of the CRT. There is a green tint over everything in the bottom right corner. I've tried purity setup and deguassed the CRT multiple times and it won't go away. Is the shadow mask bent too much?

Do you get a pure red field when doing the purity setup, or is it discolored in the bottom right? The early tubes with "positive guard band" (the holes in the shadow mask are smaller than the phosphor dots) could have white field impurity even when the individual color fields were OK. A really precise purity setup would involve viewing the beam landings with a telescopic microscope (RCA WG309A microscope) to see if they were in the center of the phosphor dots.

The later "negative guard band" tubes (Zenith Chromacolor, for example) where the holes are larger than the phosphor dots, would illuminate the phosphor dots evenly even if the purity adjustment was slightly off, eliminating white field impurity problems.

Yes bottom right discoloration on the pure red screen. So I'm going to need a microscope?

Yes bottom right discoloration on the pure red screen. So I'm going to need a microscope?

No, no microscope needed if you can see the effect in the pure red screen - only needed if the red was pure and the white was not.

I'm not familiar with the chassis mounting on your set, but I'm wondering if it's near that corner and maybe you aren't getting it fully degaussed? Can you run your degaussing coil into the back of the cabinet and under that corner?

Edit: and you don't have any loudspeaker or such magnetic item sitting near the set?

The chassis is mounted on the side, so bottom right of the screen (viewed from the front) is nearest the chassis. Under the chassis in that nearest corner is a choke.

Phil Nelson

http://antiqueradio.org/art/RCACTC-7RearOpenAtPurchase.jpg

http://antiqueradio.org/art/RCACTC-7ChassisAsFound.jpg

Hope he's familar with the degaussing procedure.

1. Have the TV in the location and position it's to be used in, and have it warmed up and running.

2. Have the degauss coil at least 6' away from the set, then turn it on.

3. Move it in and do the degaussing, then move it at least 6' away before turning it off.

If it's turned off while close in, it will gauss the set instead of degauss it.:eek:

Also please note I am using a degaussing coil from a junk TV. I am not 100% sure that I may be doing it completely right. Does anyone have a good video explaining the process in depth?

are there edge purity adjusting magnets? look at the mounting ring on the CRT, looks like large metal elongated circlips.

Also yoke droop may be an issue.

here is a degauss video

https://www.youtube.com/watch?v=7ks1uI7g_7k

I think I do see those they are a u shape and on the convergence assembly where the magnets for static convergence adjustments are.

no they are on the CRT mounting ring if you have them. NOT on the convergence or yoke. see pg 21 of the factory service manual.

They look like little clips? I think I see them.

see pg 21 of the factory service manual.

Ok I see them now.

To check whether little magnets around the edge are the solution,
try a refrigerator magnet. Don't hold it close unless that cures the problem ...
you could magentize something. Bring it up slowly from the side towards the
problem area, rotating it every possible direction as you so this.

I've used this method with a CRT device we use in my Physical Chemistry
teaching lab: the beam in it normally runs from 10 to 150 volts over all but the
last 1/8 inch .. imagine a 5 inch CRT with a shadow mask, the cathode
at 0 volts, final grid in gun and mask at 10 to 150 volts, actual screen at 5 kV.
Magnetic field nightmare. Little magnets work great.

are there edge purity adjusting magnets? look at the mounting ring on the CRT, looks like large metal elongated circlips.

Also yoke droop may be an issue.

here is a degauss video

https://www.youtube.com/watch?v=7ks1uI7g_7kAnd if you look at about 13:20 in the following video you can see how it looks when backed away from the set and not using the variac.

https://www.youtube.com/watch?v=Awd-R-vVP6A&feature=youtu.be

.

I have also noticed that on the first 15 minutes of having the set on the focus is really bad and everything is blurry and has a 3d effect like bad convergence. After about 15 minutes it fixes itself.

Drat! Just lost my color again. This time no faint colors in the color bar pattern. This happened as I was moving the yoke while doing a purity adjustment. What happened?

I'm thinking a loose connection somewhere.

The fact that your TV "fixed itself" after it warmed up suggests that and I doubt futzing with the yoke would cause color loss on its own.

Is the color killer control turned fully to the 'wide open' position?

Is that on the chassis in the center of all the color circuitry tubes?

The controls are identified on page 24 of the factory service manual.

The color killer ("killer threshold") control is inside the Contrast control shaft. Pull off the Contrast knob and use a thin screwdriver to adjust.

Phil Nelson

OK my only problem left now is for the first 10-15 minutes of operation everything is out of focus. After about 10-15 minutes it fixes itself and is relatively clear. What needs to be done?

Does it suddenly jump into focus, or get there gradually? I presume the focus control does not have enough range to make it sharp when you first turn it on? If the change is gradual, it may be a tube.

It is gradual from what I think I see. It slowly comes into focus.

you can try replacing parts OR you can try to figure out what is going on.

parts would be the resistors/pot/tubes in both the focus/HV regulation.

that's a lot of parts, and you risk taking a working set and making it not working from needless stress of part changing.

OR to figure out what is going on, use the HV prob and check the focus voltage from startup until focused. See if its changing and which way is it going (up or down). if no change in focus voltage yet change in focus on the screen then monitor the HV the same way, from startup blurry to focused and see if its changing. These are non invasive checks not likely to hurt anything.

after you find which voltage is changing effecting the focus, then you can diagnose the circuit.

I have an idea where the problem is but I prefer to withhold that to prevent unneeded part replacement. The voltage checks would confirm.


if you want to try one quick thing go for the obvious, focus problem, focus tube, that is what the tube jockeys did back in the day.

Look for corrosion on the focus pin on the picture tube and in the socket itself. My CTC9 had this problem and cleaning the socket cured it.

Look for corrosion on the focus pin on the picture tube and in the socket itself. My CTC9 had this problem and cleaning the socket cured it.

good point, Sometimes the corrosion will follow up the wire.

good point, Sometimes the corrosion will follow up the wire.

DITTO! If that doesn't work replace the 1V2, and see if it helps. Also check the socket connections on the 1V2 socket. Had corrosion on the CRT socket of the CT-100 I was once steward of, and the focus behaved in a similar way. I did wind up replacing the HV wire from the socket to the 1X2 base (CT-100), so it did follow up the wire a bit. Cleaning the socket and CRT pins also helped.
Hope this helps! :yes:
Kevin

Also just noticed there is this really annoying hum coming from the speakers whenever I try to watch TV on the set. I can barely make out the sounds from the programming over the humming. I tried messing with the fine tuning and trying different channels on the TV. Can't get it to go away. Also know the picture is very clear but the humming is the only bad part. Also the humming gets VERY loud when text appears on the screen. What is going on with my tuner? It never did this before.

My guess, a filter cap or something with the audio circuit.

If the hum is only when receiving a signal, then it is an effect of the signal and not the power supply filtering. It will probably be worst with high contrast/fine text on the screen. There are a number of causes for it. A predominant one is video over modulation....The audio is FM the video is AM...when AM over mod occurs it also inverts the FM carrier and this shifts it's phase by 180 degrees (a form of phase modulation). FM and phase modulation are so closely related that a detector for one will receive the other (and vice versa) with an integral or derivative operation preformed on the recovered modulating signal.
This PM audio carrier distortion becomes an annoying buzz when demodulated. The only solution is to turn video modulation down (if you have a modulator that supports this such as a blonder tongue AM series), or get another modulator.

There is also the potential of audio misalignment. which can accentuate this effect on some sets.

Tried adjusting the AGC?

:nerd:

Feeding a signal through the BT modulator that fixed the focus and the annoying hum. It was over modulating that is what was causing it. Only thing left is that annoying yellow discoloration on red based colors. This happens only in the bottom right corner of the CRT face. Like I said I have degaussed this set multiple times. It is mostly noticeable on red colors and orange basically any red based color. Is this edge purity issues?

Sounds like purity.. Did you do purity set up, doing red first? Sometimes it may be where you have the set sitting.. It's happened to me before..

Ive done purity in all the ways possible except for the edge purity. I can't seem to get a full red screen when sliding the yoke forward while doing a regular purity.

And you've tried moving the purity rings around to where the red blotch is in the middle? On some sets I notice if it's slightly off centered the red fills in much better...

I've tried that too no luck. I haven't tried putting it slightly off center though. Should I try the edge purity or just off center the red splotch a bit in the regular purity?

I don't know what edge purity is.. Just off center the red slightly in different positions, and keep trying..

Here's the standard purity procedure..

First do the degaussing as discussed earlier.

Turn the G and B screens fully off. Turn the R screen up.

Slide the yoke back as far as it'll go without disturbing the other neck components.

There'll be a red splotch. Use the purity rings to exactly enter the red splotch.

Slide the yoke forward until the red splotch fills the screen and best R purity is achieved. The yoke's 'sweet spot' for best purity will be about 1/4" to 3/8" short of being fully seated against the CRT bell. Tweak the purity rings again slightly if needed.

(if the set lacks auto-degaussing, first be sure the set is in the same location and compass heading it'll be used in.)

Just trying to follow, so the signal source was causing an out of focus picture that would resolve after a few minutes? Never heard of that.

Well it went away after I hooked up the BT modulator and adjust the video and audio modulation down. So either it magically fixed itself in those few minutes when I was hooking the modulator up or fixing the over modulation stopped the lack of focus and the buzzing.

1) I don't believe fixing overmodulation will fix focus. Apparently you have been using the word focus to describe something else, or it has to do with too much drive pulling down the high voltage, or something else I can't tell from your description.

2) Does this set have hairpin shaped wire gizmos on the CRT mount? These are edge purity adjustments - turn them this way or that until your blotch is compensated.

BAD video frequency response can look like bad focus.

Yes that is what it was

BAD video frequency response can look like bad focus.

as is smearing yes, but I still don't understand why it would self resolve after running for a few minutes.

And if it was a freq response issue, is it with the TV or the Modulator? If its fine with the BT then that would clear the TV as the issue.

So it would have to be with the orig modulator. The OP should try the orig prob modulator on another set and see if the "focus" issue self resolves or is not a problem.

These kind of problems are very hard to understand and diagnose. Perhap a video of the problem (both the initial lack of "focus" and the subsequent resolution) would be helpful when asking the group for help.

Perhaps it was tricking the AGC into an operating point where the normal signal was over/under driving the IF.

I cant see it being agc, most of the AGC rca stuff I have run into is either it works or its set incorrectly. incorrectly would be a under contrast pic that I would not describe as out of focus but more like lack of contrast. Over load it and you get a dark pic or loss of sync, but again more like too much contrast.

The only defect I recall in AGC was on a zenith with an open cap in the circuit, it would manifest as overly critical range (complete wash out of pic to complete loss of sync in about 1/8 of a turn of the pot.

Maybe the OP can duplicate the prob with the old modulator and this time get some video of it. Its nice to see different problems and solutions, may come in handy in the future is someone runs into a like problem.

I am still wondering exactly what it looks like, focus mean something very specific to me and I just cant get there with signal source. I wonder if the OP ever tried adjusting the focus control to see if there was an optimum setting somewhere if going either way it would get worse. That would tend to indicate the focus voltage control is working and getting the correct voltage. Then if it went out of focus would touching up the control bring it back. Again to establish focus voltage as the issue.

If it was smear from IF response then the focus adjustment should still work just getting the most in focus smear, with out of focus smear on either side of the adjustment optimum setting.

Here is the set after I fixed the edge purity problem. I think I finished it once and for all except the screen is a bit tilted. Here is a video of the set. Does anything need to be done still? https://www.youtube.com/watch?v=mwJ522Hmxfw&feature=youtu.be

looks good, just enjoy it.

Alright finally done! Thank you all here so much! A big thanks to you Dave for sticking with me this whole time. Would have been a nightmare without you and all the great folks here at videokarma. I will post any problems I encounter with the set here. Hopefully no problems will surface for years to come. Full steam ahead on the Admiral restoration now!

I think I finished it once and for all except the screen is a bit tilted. https://www.youtube.com/watch?v=mwJ522Hmxfw&feature=youtu.be

That would be an easy fix.. Just adjust the yoke to the right or left slightly.. You should be able to do that with your toes..

That looks great. Enjoy it, fiddle with it often and never leave it on for more than a few minutes if you need to leave the room.
I miss my old CTC7 metal box and later, I did get a CTC5 Aldrich recapped but it was not nearly as much of a quality set!

Worth the wait, wasn't it? Congrats!

Totally worth it no doubt! I have to admit I was discouraged when I couldn't get my horizontal hold to stay. I am glad I stuck with this set. Being a beginner to this hobby and restoring an early color TV as my first full restoration gives me confidence that I can tackle most of the sets I find b&w or color. This is really fun. :banana:

Good job. The picture looks great. 50's color sets are not easy to work on.

i think a 2nd coat of poly on the cabinet would have cured all the problems with that set, would have been faster then running it and in hopes all will fix itself. lol,lol :yes:

Congratulations! Very nice picture! I am looking forward to seeing pictures that nice on my CTC-7 Sanford, once I replace the 21CYP22, and more caps! It's the oldest color set I've ever owned.

Thanks Dave! I just noticed something interesting. There appears to be 3 phosphor errors on the face of the CRT. Two of the errors are missing their red dot in the triad of the RGB dots. And one is missing a blue dot in the triad of RGB dots. Could I have caused this or could it have been a manufacturing defect?

Thanks Dave! I just noticed something interesting. There appears to be 3 phosphor errors on the face of the CRT. Two of the errors are missing their red dot in the triad of the RGB dots. And one is missing a blue dot in the triad of RGB dots. Could I have caused this or could it have been a manufacturing defect?

It may be a manufacturing flaw. My Zenith Roundy has the same issue in a couple spots.

Most likely a manufacturing defect, I have also seen this in CRT's that have been rebuilt. I have a Zenith roundie with a Channel Master rebuilt 21FJP, that has a small error, that is hardly noticeable. All it would take is for a small chunk to fall down onto the mask, during the neck removal or reinstallation process, especially during rebuild.

I've got that on a couple of sets....One has a green/blue-green dot where a blue one should be.....Very noticeable on a VCR blue screen.

No way you can cause a single phosphor dot to disappear. This is a manufacturing defect. Normal to have a small number of these. The maker would have a QC spec saying where on the screen they could appear, and how many, before it was considered a reject. For example, they might define a center circle where none were allowed, a larger radius allowing a certain number, and then the remaining area with a larger number allowed, plus perhaps an over-all total maximum. Don't recall if these numbers typically show in the published specs; they might be published for a professional monitor though not for the tube itself.

No way you can cause a single phosphor dot to disappear. This is a manufacturing defect. Normal to have a small number of these. The maker would have a QC spec saying where on the screen they could appear, and how many, before it was considered a reject. For example, they might define a center circle where none were allowed, a larger radius allowing a certain number, and then the remaining area with a larger number allowed, plus perhaps an over-all total maximum. Don't recall if these numbers typically show in the published specs; they might be published for a professional monitor though not for the tube itself.
That is pretty cool right there! There are about maybe 5 of these and they are away from the center of screen. Must have barely passed QC!

It was the same situation when computer hard drives first came out. There were always some bad sectors, but they were mapped out and the hard drive controller would not try to write to the bad sectors. Today, I doubt that there are any bad sectors on hard drives.

Anyone have any original advertising literature with my pensbury featured in it? I'd love to find one.

Most likely a manufacturing defect, I have also seen this in CRT's that have been rebuilt. I have a Zenith roundie with a Channel Master rebuilt 21FJP, that has a small error, that is hardly noticeable. All it would take is for a small chunk to fall down onto the mask, during the neck removal or reinstallation process, especially during rebuild.

Dave - Id take this any day over what happened to my RCA Hi-Lite 21FBP22 - neck just neatly sheared itself and went to air right where the blue lateral spring rests:sigh:

Dave - Id take this any day over what happened to my RCA Hi-Lite 21FBP22 - neck just neatly sheared itself and went to air right where the blue lateral spring rests

Ugh...that really stinks. Was that tube a rebuilt, or one that had been in service and suddenly broke? I have not seen that happen yet, but I'm always careful about not making yoke and purity clamps too tight, and I have wondered about the tension on the blue lateral magnet, more than once.

Dave - Id take this any day over what happened to my RCA Hi-Lite 21FBP22 - neck just neatly sheared itself and went to air right where the blue lateral spring rests:sigh:

If you think that sucks, then put your self in miniman82's shoes....He had that happen on a working prototype metal cone color CRT. The neck glass near the base one day randomly decided to fracture, and there went a few k dollars worth of it's value.:no:

Just found out where this set came from and who owns it. This set belonged to Mrs. Rose Roti who lived on 1031 Woodbine Ave (cool house) in Oak Park IL. Sadly, Mrs. Roti passed in 1997. Wonder what she would think if she saw the set working again. :scratch2:

She'd probably be less surprised the set was living again than that she was.

She'd probably be less surprised the set was living again than that she was.

You're probably right...

Turned the set on today after a month or two of sitting dormant. There is a complete absence of red. Red gun checks brilliant red screen and background react as normal. It is just that I have no red in the color spectrum. What could be the cause of this?

Resolved. X Demod tube had a burned out filament.

That's an example of why restored sets are always a "work in progress".:)

Hi, Very glad to know it was only a 12AZ7 gone bad. Just a little hint about color loss or intermittent, but only for the early production chassis with wax caps: wax dripping on the -Y output sockets can cause loss of color(s). Cleaned up the socket, and put in Orange Drops. Problem solved! :yes:
Kevin

Hi, Very glad to know it was only a 12AZ7 gone bad. Just a little hint about color loss or intermittent, but only for the early production chassis with wax caps: wax dripping on the -Y output sockets can cause loss of color(s). Cleaned up the socket, and put in Orange Drops. Problem solved! :yes:
Kevin

Thanks for the tip! I used a 12AT7 in place of the 12AZ7. 12AT7 is identical to the AZ7 except for heater current and a lower gain. The 12AT seems to make the reds a lot more balanced with the other colors even with red turned all the way up.