OK will take some reference photos today. On some boards that irritating transformer wax has dripped onto some boards. Could that be shorting anything out? I think I might have dripped onto the video board.

the wax is not a problem, unless it prevent a tube pin from making contact, not a likely problem.

Ok took some pictures of the boards here they are http://imgur.com/a/oTaRJ
scroll down all the way to seem them.

Ok the video board (one with the brown drops and wax on top).

those brown drops should be tested with your tester.

you should replace the orange electrolytic.

some browns are good some are not, only way to know for sure is to test.

You have some vintage looking replacement caps on the horz board as well, whats the deal? did you test them before installing?

if you find the browns to be testing bad then you may be in for a total recap of ALL of them. test the ones on the video board 1st and see how they check.

make a video showing your test process.

What do the vintage ones look like?

clear covering silver tubular.

modern stuff is going to be dipped radial leads or yellow axial.

I replaced one that was a bit leaky. I always get so nervous when working on the boards I always feel like I might have damaged the traces. Are the traces easy to break?

only if you use bad technique. don't over heat, don't put any pressure on the lead that would tend to push the trace away from the PCB. Using solder wick helps.

Are the .01's even critical?

depends on the circuit and the amount of leakage.

for the horizontal

check the one I mentioned, its the AGC filter cap. If during your testing you find the browns are bad then you can plan on replacing them all. BUT you only want to do a couple at a time. Leave the Chroma ones alone for now, just stick with the ones on the PCB.

do a video of the test process, showing but the check for value and leakage.

OK I will go and buy some caps today.

only if you use bad technique. don't over heat, don't put any pressure on the lead that would tend to push the trace away from the PCB. Using solder wick helps.

I've been using a de-soldering iron for several years now. Seldom, if ever damaged a PC board. :scratch2:

I've been using a de-soldering iron for several years now. Seldom, if ever damaged a PC board. :scratch2:

what kind? I have the one with the bulb built into the tip. Works well on thru plated PCB where the leads are not bent over, not as well on non thru plate with bent leads as its hard to get a good enough seal to really get suction on the parts to remove the solder.

On the subject of leads being bent I find it is NOT needed on RCA pcb for the most part as you can get a good joint even with out the thru plating. That being the case I do NOT bend them rather just insert, bend one lead a bit to hold in place, solder the other straight thru lead, then unbend the remaining lead and solder. clip off and done.

IF the leads are straight in the 1st place, I go to the solder remover gun with the built in bulb.

Ok bought the caps and decided to get a nos 6CG7 the guy at the store told me I could piggyback two 1 uf caps to make a 2uf cap in place of the 2 uf electrolytic can this be done? I can't stick two through one hole on the boards so I think I'll have to just twist tie the leads of one to the other one going to the board.

Here is a video of how I test my caps.

something wacky going on with that tester.

the value test should show a fully closed eye that opens as you dial around, then you can read the value.

You should try this on a new cap and get that tester working. there is a null setting of the eye that is your target.

The leakage test seems to be working, just compare a new cap and make sure its working the way you think it should.

On the 2uf , 2.2uf 450v axial caps are at mouser.

IIRC there is a setting (actually a range) that you select for measuring capacitance. there is a separate setting on the same knob that is used for checking leakage. I did not notice you making a change when going from capacity to leakage, maybe I missed it.

Well I am more concerned about fixing the set now than I am concerned about the cap checker. I think leakage is all I really need for now. Back to my previous question, could I stack two 1uf caps to make a 2uf cap? The guy at the local tube store here down by the Florida hospital said I could. But I thought I read that stacking caps cut the value in half?

Wiring two caps in parallel adds their values. Wiring them in series decreases the capacitance value. Combinations also affect the voltage rating. The details are explained in the following article:

http://antiqueradio.org/recap.htm

Scroll down to "Substituting for Unavailable Values."

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

Caps in parallel add and have a voltage rating of the lowest voltage rated cap.

Caps in series cuts the value in half if the two caps are the same value. The voltage doubles if the caps are rated for the same voltage. Just to finish the thought, some recommend putting equalizing resistors across the series connected caps. This is not applicable to your current situation.

OK got the board recapped... I am extremely nervous to whether I broke any traces or made good solder joints. The damn wax everywhere made it very difficult to do things.

Got it back in... Horizontal is only a bit better and vertical isn't any different. And the picture signal still isn't great there is a lot of snow mixed in with the show being broadcasted and it is pretty hard to make out what is being shown in the show. Sound is crystal clear though.

there is a lot of snowAre you broadcasting a signal with your B-T modulator, or connecting your video source directly to the TV? You might want to connect directly, to simplify the equation while trying to obtain normal picture quality.

Did you ever clean the tube pins and sockets in the RF and IF sections? Have you tested those tubes recently? It's not unheard of for a tube to fail, even though it initially tested good.

Have you cleaned the tuner? (By cleaning, I don't mean spraying a gallon of WD-40 inside and working the channels a couple of times, which can soak phenolic parts and do more harm than good. I mean opening the tuner and cleaning the contacts with a Q-tip and DeOxit.)


Phil Nelson

Did Clean the tube sockets and tubes but not the tuner itself. Hooked the input directly to the RF out on the BT modulator and the picture is crystal clear.

OK I think I am ready to start the picture quality adjustments... What should I do first?

Sounds like there is problems with the BT Modulator.. It's very common to find them defective on eBay.. The very first one I bought had issues like that.. Even when connected directly I could not get a picture without slight noise.. I could not fix it, even after recapping and replacing the transistors in the power supply.. I would suggest not using the BT modulator all together unless you know it's working properly... Coax output of a Cable Box, DTV converter box, or DVD player is going to show you the real results...

Went ahead and tried some preliminary convergence I think I did OK the lines in the middle look pretty good.

Hooked the input directly to the RF out on the BT modulator and the picture is crystal clear.That answers your question about snowy picture. Quit using the modulator to broadcast and stick with a direct connection until your TV works normally.

As to which picture quality adjustment to do first . . . don't waste time on any of the color adjustments until you have a flawless black and white picture. No horizontal or vertical jitters or bending, no problems with vertical and horizontal linearity, and so on. Going back to mess with those things after you have spent hours on color adjustments may force you to do the color adjustments all over again.

The multi-step procedure for color adjustments is described in pages 28-38 of the RCA factory service manual:

http://antiqueradio.org/art/RCACTC-7TelevisionFactoryManual.pdf

You begin with purity. After that, you set the grayscale using the screen and background controls (the manual calls this "kinescope color temperature adjustment"), and so on. Do these procedures in the order laid out in the manual, and if you can't get the right result at any point, stop and find out why.

BEFORE doing all of that, you might want to look very carefully at your picture to judge whether those procedures are needed. It's quite difficult to get perfect convergence around the far edges (top, bottom, sides) of a roundie color picture. If yours already looks good, you might want to let sleeping dogs lie. Look for color fringing in the edge zones -- that's a sign of less than perfect convergence. If your TV looks nice and watchable already, maybe it doesn't need twiddling.

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

I would probably be satisfied with it now but I can't be sure since the color oscillator is running at the wrong frequency so I cant get any color.

OK got the grayscale adjusted to the best I could do. Now how do I get my color?

OK read up on the color issue. I guess I have to adjust a coil? How can I do that without the proper tools?

Follow what the manual says, usually it goes something like this:

Ground the reactance tube grid with a color image on screen, and adjust the local oscillator coil till a rainbow pattern just floats by. Remove the ground from the grid, and color should snap right in. Of course this assumes there aren't other problems with the set, such as the tuner being off frequency which will throw off the chroma response so far that the set doesn't even see it (even though a normal B&W image appears, this is no indicator that the tuner/alignment is anywhere close to correct).

What kind of tool should I use adjust the coil? A type of screwdriver?

Do you mean you have no hint of color no matter where you turn the fine tuning knob?

The adjustment procedure for the oscillator is described in pages 36-37 of the RCA factory manual, but if you don't see any color at all -- maybe rolling "rainbow" color bars, for instance -- that procedure may not get you anywhere. (In that event, I would start by doing resistance and voltage checks on the 3.58-MHz oscillator tube to get some clue whether the oscillator is capable of running at all.)

To do the adjustments described in that procedure, you need non-metallic tools -- a screwdriver for L704 and a "diddle stick" with an Allen-like head for the other adjusters mentioned. You may find such tools listed as "TV alignment tools" on eBay.

Phil Nelson

I will get rolling rainbows on the color bar pattern but only when I turn the fine tuning all the way clockwise.

Woah all of that looks complicated... Can I do this without a vtvm?

cant even get a rolling rainbow anymore. I am so confused.

Diddle sticks, they are a plastic allen sort of thing. You can't use a metal tool, because it screws with the tuning of the core when you attempt adjustments. You can buy a whole set of them real cheap on eBay, just look for TV servicing tools.

OK. Where is the reactance grid and how do I ground it?

Diddle sticks, they are a plastic allen sort of thing. You can't use a metal tool, because it screws with the tuning of the core when you attempt adjustments.

I learned this the hard way trying to tune convergence on an RCA delta gun set and by the time I figured out that you needed a non metal tool, I had disintegrated one of the tuning slugs.

Diddle sticks as in these? http://www.ebay.com/itm/Radio-TV-Alignment-10-pc-Trimmer-Tool-Kit-Set-63-910-Philmore-NEW-/121699819695?pt=LH_DefaultDomain_0&hash=item1c55dfe0af

Something like this should suffice:

http://pages.ebay.com/link/?nav=item.view&alt=web&id=191638196567&globalID=EBAY-US


Ought to get one for myself, my diddle sticks are pretty wore out...

I will try and pick that one up. If I don't win is there anything else listed that will work?

Follow what the manual says, usually it goes something like this:

Ground the reactance tube grid with a color image on screen, and adjust the local oscillator coil till a rainbow pattern just floats by. Remove the ground from the grid, and color should snap right in.

http://antiqueradios.com/forums/viewtopic.php?p=2347598#p2347598

.

OK. Where is the reactance grid and how do I ground it?Look at the description of Step 4 and the photo on page 36 of the RCA factory manual (I provided a link to that manual above). Step 4 tells you to ground the reactance tube input at the junction of C726/R743. If you look at the schematic on page 50 of the manual, find that junction and then follow the connection to pin 9 of V707-A, the 6U8A reactance control tube. Grounding the point shown in the manual effectively grounds the input grid of the reactance tube.

Step 4 also tells you to ground terminal D of transformer T701, also shown in the photo on page 36.

You can ground these points with two clip leads -- wires with an alligator clip on each end.

After grounding those two points, you can try (gently!) adjusting the reactance coil L704, also shown in the photo. If you don't have a plastic screwdriver, you can make a tiny adjustment using a metal screwdriver and then pull it out and hold it at least a foot away from the coil. See any difference? You want to slow the rolling of the color bars. This is a cowboy way to do it -- the bars may go nuts when the screwdriver is in the coil and your body capacitance affects the circuit. But when you pull it out and step back, you should be able to tell if your adjustment made any difference.

If adjusting in one direction makes the rolling faster, try adjusting in the opposite direction. The ideal is for the bars to be static -- floating without any roll -- but a very slow roll is better than a fast one.

If you get the bars to stop rolling, remove the temporary ground connections and see what the picture looks like.

If the cowboy adjustment doesn't work, I would do careful checks of resistances and voltages on V707, which acts as both the oscillator and the reactance tube.

Phil Nelson

Ok just won the auction for those alignment tools. I will take a stab at it when they arrive!

Phil,
Not to be a fuddyduddy:o but I would heartily recommend against sticking anything into an adjustment slug other than the prescribed tool. The slugs are sooo fragile and easy to bust.

Good point. They made special tools for a reason (sometimes more than one).

Phil Nelson

a video would be a good idea of what you have now. Show some reg color programing and adjust the fine tuning from smear to wormey

before touching any coils you really need to eliminate all other possible issues. diddle stick drift is the worst thing to deal with.

based on the video it should be determined that the color osc is running and or synced properly. color killer is also an issue. There is a lot that cause the color circuits to not work right, coils adjustment would be the last place to look, esp if the osc is not running or is WAY off. any tweeks would be minor UNLESS someone has gotten into it (the reference to diddle stick drift).

of all the color sets I have worked on with respect to coil adjustments, the most that was required was a 1/4 turn on coil in the osc circuit (rare). Most of the time it was a dirty pin/weak tube/cap/pot issue. Its aways best to start with the obvious and easy. fine tuning and signal 1st, Tubes in chroma, wiring from controls, the pots themselves, settings of color killer.

To the others that are helping, I am pretty sure the OP has not touched any of the now suspect film caps in the chroma circuits.

I am pretty sure the OP has not touched any of the now suspect film caps in the chroma circuits.Aha. Yes, start with the obvious. After I recapped my CTC-7, including chroma circuits, it looked so good that I did not mess with any of the color setup. Sometimes it's better to let sleeping dogs lie.

Phil Nelson

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

Is the chroma located in the underside portion of the chassis? Because I don't see it as a board.

Under. Note the yellow and orange caps in this photo of my CTC-7:

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

The pile of "brown drops" and one bumblebee show what I replaced.

The full CTC-7 restoration article is at http://antiqueradio.org/RCACTC-7ColorTelevision.htm .

Phil Nelson

Basically all the brown drops? Some of them are just buried in there. By the way a big thanks to you Phil for helping me out.

I believe I replaced all of them. The failure rate of those on the boards was so high that I couldn't justify keeping that type of cap anywhere in the TV.

I recommend trying out the TV frequently as you recap, rather than replacing all of 'em at once. If you make a wiring mistake or install the wrong value cap, which is easy to do, the problem will be immediately obvious and you won't have to go nuts trying to find the error amongst two dozen replacements.

Regards,

Phil Nelson

At noob-level experience, it'd probably be advisable to power-up after each part is replaced (IMHO).

Well going to need more caps I guess.

Diddle sticks got here today. The smell terrible but everything is here. I will start to recap the chroma circuit later tonight.

OK just finished recapping the entire chassis with the exception of two caps. :D

OK horizontal lock is once again horrendously bad goes off sync in less than 30 seconds does this on the bt modulator the lcg-400 and the converter box. Also no color still but a slight rolling rainbow that isnt rolling at all.I did not replace one electrolytic cap located in the chroma since I don't have that value could that be screwing things up? Tried adjusting the 3.58mhz oscillator coil that yielded nothing. I am pretty frustrated as to why the horizontal hold is so bad and why I still have no color. ugh :sigh:

pointless to worry about color until the horz is solid, with out a good horz the burst gate will not work.

well I'm at a loss to what could be causing it. The chassis is recapped and the horizontal board is recapped. Could a coil need to be adjusted or something?

could be sync could be the osc. Need to know which to know where to start.

Are those coils? Or circuits?

DO NOT adjust coils. you need to post up videos of the problem.

It could be that the owner is over his head in this one. Or it could be a problem
insolvable by logic, even by a real hot-shot on the spot with good test equipment.

I have good test equipment and experience ... I had the same problem (intermittent
horizontal sync) in my CT100 --- its only real difficulty after a recap. I tried for weeks
to figure it out with a two channel scope on various pairs of places and never
succeeded, but did prove it was the oscillator itself.
It was only cured by a total, all at once, re-resistor of the horizontal oscillator.
No removed resistor tested bad either at room temp or heated with a heat gun
(at low voltage). All solder joints had previous been resoldered. So it was a
resistor changing, instantaneously, from one value to another, at voltage.

I suggest, if he can use a scope, first measure the waveforms in various places
in the sync circuit, when its working. Then first attach the scope to the plate of
the 2nd video amp and measure the waveform when the set is in sync.
Leave it attached there. Attach a zero to minus 10 or so volt bias box to pins
F and G of the PW400 board (AGC amp) and adjust so that you get the correct
signal on the scope. Leave it there and start measuring waveforms in places in the
sync circuit and the horizontal oscillator with it in or out of sync. Be patient!

That's just about all you can do to pinpoint problems unless somebody else has a
better suggestion. That's how I proved my problem was the horizontal oscillator.
Ideally this would be done with the horizontal output tube removed, as described
on p. 14 of the service notes (with schematic, at ETF) ... BUT! ... that requires
a 100W 1500 ohm resistor.

Here is a video of what is currently happening.https://www.youtube.com/watch?v=937DWhVRXSw&feature=youtu.be Note after about 3 minutes or so the horizontal becomes a lot more stable.

Here is a video of what is currently happening. Note after about 3 minutes or so the horizontal becomes a lot more stable.

No attachment or pointer to one.

Edit 15 seconds later: it appeared!

Sorry about that

OK after about a 5 minute warm up period the horizontal hold becomes acceptable but not that great it will stay locked but will bend and swerve on some certain pictures. I just need color now the horizontal is good enough for me now. I just want color.

how much range of adj to you have after it locks (can you turn the horz hold and shift the pic left and right) You should be able to turn the knob nearly a full turn without it losing sync, Can you flop it both ways (continue to turn past lock and the diag lines go the opposite way).

have you adjusted the noise inverter? (note the position its in now, then try fully CCW)

I will adjust the noise inverter. The hold flops both ways. I can get a full turn counter-clockwise and a bit less than a quarter turn clockwise.

horz hold, why are you setting so you only get 1/4 turn CW? set it in the middle of the range so you get equal adjustment before loss of sync.

How am I even supposed to tell when I have it in the middle? Does a full picture mean the middle?

you can turn it CCW 1 full turn before losing sync

you can turn it CW 1/4 turn before losing sync

so you are setting it too CW to start with.

OK I get a bit less than a half turn on both sides. adjusting the noise inverter did nothing it was already fully ccw.

ok so 1/2 a turn will cause it to flop to diagonal lines either direction?

Yes sir

ok on the horz board is a 68k resistor. look at the schematic its the one that is across the coil. You will need to lift one leg of it to check the value. report back, if its way off it can make the adj to crit, I think you should have more of a range than 1/2 turn. It would need to be way high like 2x R605

after you check that there is a procedure to set the sine wave adj coil, should not be needed unless its been messed with.

Lastly regarding color, did you check the color killer pot setting? IIRC fully CCW is no killer, fully CW will kill the color.

Did not mess with that pot. Will pick up on this tomorrow currently going to be out of town till tomorrow afternoon.

Is the color killer pot on the top side of the chassis or the bottom?

look for hollow shaft on contrast pot, thin screwdriver should fit inside.

Messed with the killer pot was turned all the way ccw turned it clockwise fully and now I have a rolling rainbow and my color bar pattern. I am hearing this is caused by the 3.58mhz color oscillator and it is fixed with a coil adjustment.

If you have a standard color bar pattern, but the bars rather than being a solid color are RGB barber poles Color synch is achieved through tuning the chroma osc. transformer/coil.

before you start messing with coils, try adj the fine tuning, going past optimum tune just to see if you can get a lock. The best color will be in the wormy mode of the tuning just before losing sync.

the color killer should be setup so when there is no programming just snow, start fully CCW should be some color in the snow, advance until the color in the snow just goes away. I have a video on this.

Fine tuning does nothing at all I spent 30 minutes messing with it.

So uh, should I adjust that coil?

Color sync adjustment (to correct barberpoling) is done with the Reactance coil. Phil Nelson should be able to direct you to it.
Re. the color killer adjustment, for now leave it fully in whichever direction gives color.
The color killer feature is actually moot nowadays. It was useful in the days when lots of broadcasting was still in B&W, to prevent unwanted color confetti in the B&W picture.

Its OK to adjust the reactance coil only, L704 in the schematic from RCA.
See instruction on p 27 of manual. It should snap in and stay stuck in if
you don't ground the input as described on p. 27. Its best not to do the
rest of the adjustment described unless it locks, However its a good
idea, if you have the equipment, to check all the waveforms and report back here.

I did try to adjust the top portion of that coil and I got no response whatsoever.
The rolling rainbow did not visually decrease or anything.

L704 does not have a "top" its a single slug coil. I hope you were not adj T704 which is a transformer with a top and bottom.

did you make a video of the adj you were making with the fine tune? Not sure I understand when you say it makes not difference at all. do you mean nothing at all happens when you adj? as in the fine tuning is not working at all?

I hate to keep having to say this but without video of what is happening its hard to give good advise. Your descriptions will mean different things to different people, a picture is worth a 1000 words.

Perhaps the others on this forum are ok giving advise without seeing what is happening, Its just something I prefer not to do.

I will restate the last thing you should be doing is adjusting coils, I would do tube swaps in the color osc circuits 1st, often the osc tube is a problem.

I do apologize for not always giving you adequate info in my posts. I am afraid I may have accidentally adjusted T704 and not L704. I will swap out some of the tubes in the chroma though and will report back with my findings.

do you know how much of an adjustment you may have made on T704?

FYI at most the L704 would be 1/2 turn either way, and the effect is instant (as soon as you move any at all the number of rolling bars should go up or down. Down is the way you want until it locks, again for me this has been about 1/4 turn). generally speaking if adjustment of coil does not have an immediate response, its likely you are adj the wrong coil. Coils are resonate devises not like pots that have a more linear response.

the tube you want to swap 1st would be the reactance/osc 6U8 this assumes you really have a color osc problem.

I pic of the color snow from the color killer adj was requested to confirm the color osc is running and working as it should(since I had no pic of the rolling bars).

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

review this again, regardless if you set is getting color programming to work, does the fine tune behave the same (pic to loss of sync).

Does the color killer work the same (snow and color snow).

the idea is to isolate where the problem is, the above gives clues. It prob is just a tweek of L704 based on my interpretation of your descriptions. BUT the idea here is to learn how to trouble shoot in a logical systematic approach.

Uploading picture now

Here it is please note that the rainbow is rolling very fast downward. And I adjusted T704 maybe a half turn both ways.

and the fine tuning does it do like in my video, gets dark and lose sync.

you are prob ok on T704 deal with it later.

If I turn the fine tuning all the way clockwise I lose the rolling rainbows. Turning it all the way ccw I lose sync.

are you sure you are on the right channel? that sounds backwards on the fine tune like you are off one channel. Try going up or down one channel from where you are and fine tune again. CW would cause you to lose sync.

Well I went one channel down and I dont lose sync at all but I lose the rolling color bars when I turn all the way ccw. The rolling color bars get a lot brighter when I turn the fine tuning all the way cw. Now on the upper channel when I turn the fine tuning cw I lose sync only after about less than a quarter turn note that I am starting from all the way ccw.

something is not right, you should be able to lose sync. I assume you are using the standard 3-4 channel output converter box?

No I am using my signal generator.... Should I hook up my converter? Would it be easier to call you for this?

Well I went one channel down and I dont lose sync at all but I lose the rolling color bars when I turn all the way ccw. The rolling color bars get a lot brighter when I turn the fine tuning all the way cw. Now on the upper channel when I turn the fine tuning cw I lose sync only after about less than a quarter turn note that I am starting from all the way ccw.

Ok I just checked mine, the CTC-7 tuner is a bit different than the one in the video(video has tunable slugs for each channel, ctc-7 has a VC that effects tuning on all channels), so its possible that you may not lose sync (mine did but just barely).

but it was def fully CW for loss of sync and CCW I would lose color sync (rolling bars) on my CTC-7.

triple check what channel you are on and what channel the output is, but IMHO you need to be on the channel that has fully CW for loss of sync/dark pic.

You may have a problem with a converter tube in the tuner, OR your AGC may need to be adjusted.

confirm the channel and fine tuning operation 1st

then try a different converter tube in the tuner to see if that makes an difference.

lastly will adj the AGC, I did not want to go there since the CTC-7 has a different approach to that than later models, but its not a big deal and you can aways reset to the orig starting point.

Triple checked everything replaced tube no luck. I am pretty sure I do know which way clockwise and ccw are. To be sure when I turn the fine tuning all the way to the right I lose the rolling color and if I turn the fine tuning all the way to the left I lose sync.

Should I try adjusting L704 just to see if I can get any color or should I leave that until I get my tuning problem fixed?

turning right (CW)should cause the pic to become dark and lose or start to lose sync turning to the left (CCW) should start to lose definition of the pic (blurry).

did you confirm the channel on the output from the signal devise? 3 or 4 for most common consumer grade RF modulators used on dvd or digital to analog converter boxes.

I suppose its possible there is a gear reversing the direction of the tuner on your set, perhaps someone with the exact same model can chime in to confirm the fine tube adjustment.

If the osc slugs used for the gross setup are way off on one channel I suppose you could have an issue with backward fine tuning.

Try another video source with a different channel output and confirm the operation of the fine tuning, see if it works the same way for different channels (assuming you have access to devises that can output to more than one channel). confirm the outputs as well with more modern tvs that still have an analog tuner.

Let me hook up my converter box and see if it is any different there.

Should I try adjusting L704 just to see if I can get any color or should I leave that until I get my tuning problem fixed?

I know you really want to do that so go ahead, give it a try. Can't hurt, just remember that it should have an instant effect, and don't turn more than 1/2 either way. I put a little flag made from tape on the top of the tool to help keep track of how much I turn. if no help put it back to the starting point.

but you should return to getting the fine tuning to work as it should even if you get the color to work.

OK hooked up the set to the converter box which is output on channel 3. Dont lose sync at all only lose the color bars when I turn all the way ccw

ok mess with that L704 and see if you can get the color. remember note how far and no more that 1/2 and look for instant changes in number of bars adj to fewer bars until lock assuming they are instantly effected.

I suspect the AGC may need to be adjusted. but that can be done later.

OK adjusted L704 nothing... Bars got brighter when I turned and when I turned back they got dimmer. I see shango066 had the same problem and it took him 3 turns until he got color.

will have to think about that. are you sure the color bar generator is working right? try adj while using a different source.

Tried with converter box no luck.

ok I will have to take a break and think about it.

what happens if you remove the 6U8? do the rainbow bars go away?

that's the color osc tube.

Yes bars disappear.

Yes, you can try L704, if it really is L704 and nothing else. I should
have warned you not to turn T704, but a half turn is not a lot.

As said before, if you are not in lock, which you are not, L704 should
change the pattern a lot with just a tiny adjustment. If it does not,
that's not the problem. If it does, change it in the direction of fewer bars
like you see. At some point, not a whole turn away from where it is,
it should lock rock solid. If it does not, turn back to where you
started, as the problem is surely elsewhere. You seem to have 4 bars or so, so it is very close.

would messing with T704 again help?

check voltages pin 1 and 8 of the 6u8 V707A tube, check with no signal.

I dont have a vtvm... Maybe I did turn T704 more than half a turn but I thought I didnt.

If I did adjust T704 too far how would I get it back to where it needs to be?

are you sure you were on L704 and not L702?

Adjusted the one by the HV fuse and the 6U8 color oscillator.

try subbing a burst amp and phase detector tube. sounds like the reactance circuit is not working.

you are going to end up looking at pin voltages, so you need to start looking for some tube extenders with test points. Check your local tube guy, you will need to get some 9 pins, get some 7 pins too as they come in handy.

Was only able to replace the burst amp. Color bars are rolling a lot faster and arent as bright.

try adj L704 with the new tube. see if there is any change in the number of bars as you adjust.

it goes from 4 bars to 5 bars.

A note about measuring voltages on flaky oscillators, which yours is.
No matter what type voltmeter you use, old VTVM or modern digital multimeter,
do NOT attach the probe directly to the circuit! This will load it down with
lots of capacitance.

Find out what the meter resistance is, usually 10 megs. Do this by measuring
a suitable voltage source like B+ with the meter, then through a 10 meg resistor
attached to the probe end. If you then measure half the voltage, its a 10 megohm meter and you make measurements with that 10 meg resistor on the probe end and
double the number. If its not a 10 meg meter, you need to calculate the correct
correction factor.

it goes from 4 bars to 5 bars.

Adjust it the other way and try more turns. Also if it is a PCB mount socket it may be prudent to touch up the socket solder joints.

OK did 2 turns and now have 3 bars of rolling rainbows.

Keep going until you have chroma synch, the number stops decreasing, or it runs out of threaded range.

1/2-3 turns is not always enough to synch a chroma osc.

Keep going until you have chroma synch, the number stops decreasing, or it runs out of threaded range.

1/2-3 turns is not always enough to synch a chroma osc.

Turned till it wouldnt go anymore on both sides. It goes away when I rotate it to the right completely. No color the bars are all purpleish :(

I think T704 might be causing this. I think I adjusted it a lot more than I thought.

If you adjusted the top slug of T704 no harm was done as long as it
is as the manual describes it. (Some similar transformers were made
at one time upside down.)

Try grounding the grid of V-707A and see what happens. Try connecting it
to a battery source of 0 to -9 volts (pot across a battery) and see what happens. Try connecting it to its own cathode through a 100k to 1 meg pot and see what happens as the pot is varied.

If this does not make it go through "no bars, just unstable" then its
the oscillator or reactance tube circuit. That's if you managed to get L704 roughly back where you started.

Is the reactance circuit located under the chassis? I recapped everything.

Yes, it's under the chassis. The 6U8A tube (called V707 by RCA or V20 by Sams) actually handles two circuits: the 3.58-MHz chroma oscillator and the chroma reactance control (aka "chroma reference osc control" in the Sams manual).

Phil Nelson

Well it cant be the reactance circuit I recapped everything the whole underside of the chassis

Why can't it be the reactance circuit? Caps are not all that's there. Could be a resistor, coil transformer, tube socket, etc. Just because the caps have been changed that is no substitute for troubleshooting. Sometimes other things are wrong.

The reason I say this is because most of the resistors I have tested on this set are barely off value.

OK. So what do you guys suggest I do? Check some resistors? adjust more coils? This project has been frustrating me lately and I would like to have it done by the time I start school which is Tuesday of next week. I am not looking for complete perfection I just want normal color on my color TV. At this rate I probably wont finish this before Tuesday next week. :sigh:

Check Resistances (including those of coils and transformers) and voltages in the osc. circuit, and re-solder the tube socket.

Just because some resistors are good in one spot don't mean all of them are good.

If he's replaced the cap that parallels the reactance coil, he oughta double check that it's the right value, since it's critical.
Surprizin' nobody's chimed in about the crystal (or maybe I missed it).

Page 18 of the Sams manual has a resistance chart showing what resistance you should measure at each pin of each tube. It's worth spending a couple of minutes to check the resistances on the 6U8A tube and compare them to the chart. These readings involve more than individual resistor readings.

If you don't have the Sams manual, send me an email via http://antiqueradio.org/contact.htm and I'll mail it to you.

Phil Nelson

double check work done (cap values and connection points)
look for crossed wires (lead dress of parts on point to point)
check pin continuity of tube sockets to circuits
use sams as a rough guide on resistance (don't get too hung up unless dif are huge, there are lots of caveats on those, read the notes)

a new xtal is a good idea just to eliminate it as an issue, not likely but no real good way to test.

test equipment is the problem, with out a good scope you are hoping to find the problem. So it comes down to guessing based on observation.

Hard to say if the coil diddling could now cause a new problem. If it was mine I would do all the above report back findings and try a new xtal. I prob have one laying around here somewhere but will have to dig around to find it.

for now NO more coil adjusting until at least you do the above. then will prob have to try the procedures laid out for adjustment of the coils that have been adjusted, mainly peaking out the T704.

I have an RCA WO-33 scope is that suitable? I am just not very acquainted with scopes. What is an xtal?

xtal is the crytal 3.58.... MHz

Where could I find one? Just google it? Or does mouser have it? And what specific package? The canned type?

Its probably not the crystal. They seldom change frequency.
More likely are the 220 and 82 pF caps attached to it and
the15 pF cap across L704.

Also ... have you tried turning C740 (RCA schematic), noting where it
was originally set.

But as I said before, the next step is to try playing with the cathode to
grid voltage on the reactance tube and see how it changes the frequency.
Making a bias box is easy, just use a 9v transistor radio battery.

Should I just make videos of me doing all this?

No videos ... just numbers!

Try measuring other circuit point voltages.

In particular: using an ANALOG voltmeter with a 10 meg resistor
between circuit and probe tip, not digital multimeter, OR
digital meter with the 10 meg resistor at the probe tip and 1
.01 uF cap from probe tip to ground, measure the following:

pins 1 and 3 of V706 (RCA) the 6BN8 phase detector and
pin 9 of V707 the 6U8 reactance tube.

Have you checked the resistance, disconnected from the circuit,
of R727A and R727B, attached to pins 1 and 3 of V706. These
REALLY should be within 1% of each other.

Try everybody's suggestions and carefully report back.

Radio Shack sometimes has TV crystals in store.

try this

find a channel that works where you adj fine tune fully CW until just losing sync or near just losing sync.

with reg programming on try adjust the horz hold to see if color will pop in.

Oh too late for that I pulled out the chassis. I tested r605 the 68K resistor and it is reading 65.5K.

So, should I replace it?

It is only 4% off if my beer intoxicated math is right. Most resistors are 5 to 20% so unless it has some special labeling saying it should be 1-3% leave it be.

Give a man a fish feed him for a day, teach him to fish feed him for life....Now for a teaching moment. The fourth band on a resistor is tolerance. None=20%, silver=10%, gold=5%...There are others IIRC but not commonly seen in tube gear. Multiply the face value by .2, .1, .05 respectively depending on marked tolerance. If the measurement is larger than face value add the product you just calculated to the face value if smaller subtract. If you added and the measurement is larger than the sum replace, if you subtracted and the measurement is smaller than the difference replace, otherwise keep the original in circuit. Next time you need to know if you should keep a resistor do the math first.

OK so it is only 4% off out of 20% so it is fine. Well then. What is causing my terrible horizontal lock then?

Its impossible to say what's causing it until it is fixed!

Whatever you do, don't give up. These things can take months.
Learn to use your scope and take pictures of it so they can be posted here.

I've got 55 years of experience and it took me weeks to permanently fix
the horizontal in my CT-100. And I have several scopes I could and
did hook up all at once.

How does the lock vary with signal strength?

so the horz lock is a problem now? I thought you had it so it would stay locked with 1/2 turn either way?

fyi, as long as you are having horz sync is issues its pointless to work on the color sync, they are related. You need to get the horz working 1st.

IF we are back to horz lock issues, a few things to consider.

AGC, keyed agc is always good for tough dogs. Make sure you check C405 a
.22 uf cap used to filter the AGC.

Note where the AGC pot is set (top of chassis near the chroma section). when having lock problems try adj just a bit if no improvement put it back to the starting position.

the deal is if the AGC in noisy or incorrectly set (cap or pot setting) then the IF amp gets whacky and does odd things with the signal, clipping etc..

this results messed up sync signals (they are the 1st thing to get clipped in the IF amp).

The normal approach to checking this would be to attach a bias box to the AGC line and manually provide the bias needed for the IF amp. Since you don't have a bias box we have to assume the most likely suspect (after the tube) and go right to the AGC filter cap.

An alternate to the bias box is a scope on the agc line set to read DC. adjusting the pot should raise or lower the DC bias from the output of the AGC supply AND the voltage should be clean DC with no "grass". the grass is a result of the loss of filtering.

I presume you have replaced the C405 in on of you mass recappings already so this may not be an issue.

Another possibility again assuming you are still having issues with horz hold and the issue is a very critical hold range of the pot (only a few degrees of adj from flopping one way to sync to flopping the other (which is NOT what you have described so I only mention for future reference) is the 68k resistor that p's with the horz hold coil. I presume its a Q killer to soften up the peak of the coil.

I do believe I did replace the agc filtering cap. The horizontal lock has gotten progressively worse with now less than a quarter turn on both sides to lose sync.
Will probe around with a scope and make a bias box.

just for fun try this a quick and easy thing.

find the 68k resistor on the horz board, read the value, it should be very low prob in 10's of ohms since its connected across the horz adj coil.


Once you have found that resistor, connect up one in parallel another 68kish will be fine. See if that has any effect on the horz hold control, you want that to be a lot broader of an adjustment. Just use some jumpers to hook it up, no need to break out the soldering iron or remove anything. Be careful when using jumpers, you don't want to short out anything.

this is generally the 1st thing I do if I think the sync is an issue.

Note this assume the osc is not the issue (can flop both ways)

Note the use of tube socket extenders so work can be done from above with the set on.

watch this to better understand the function of the sync separator.

https://www.youtube.com/watch?v=Flg5LwBadHI

How did you get the probes to stay on the extenders?

The ones I got are fiendishly designed to make this impossible.

indeed, I remove the sliding hook thing and generally just rely on the prob pin stuck in the hole of the extender, its pretty iffy but generally I can get them to stay put.

OK thanks to both of you for the ideas. Going to take a short break on this set until Monday. Will try all of your suggestions then.

Alright I think I am ready to start back up on this TV and finish it once and for all! Would do any of you recommend me doing? I did get some 9 and 7 pin test sockets (thanks to Dave for alerting the guy at the tube store near me).

Have you checked the mica caps on the horz and sync boards? They can go bad. Also, Some of them look like mica's, But are paper caps. I have had to replaced them in the ctc 5 with the same problem. Wonky horz hold.

Here is a picture of a mica cap. It is the red thing with the color dots on it. Sorry it is hard to see. Had to shove the camera in the set to get closer to the board. The set in the picture is a ctc 7c.

Says its a 680 uf with no voltage rating?

OK just going to replace ALL ceramic caps on the horiz sync board just for good measure.

Says its a 680 uf with no voltage rating?
I looked at the sams and saw the same thing. No voltage rating. Put in a modern 1000 volt cap and see what it does. Take your volt meter and measure the dc voltage with the new cap in place. See what you got. Also a mica cap and ceramic caps are two different animals. You want to check the mica caps and ones that look like them.

Will do thanks a BUNCH! Will stop by the store tomorrow and pick those up and report back with my findings.

Shouldn't that be 680pF not 680uF? Any non-lytic should not be more than .68uF in an RCA product of that vintage.

Yes they are all in PF not uf

I am so happy I finally fixed my horizontal hold problem! :D Replaced all but one of the ceramic/mica capacitors and my hold is now stable. Thanks a whole bunch to roundscreen who suggested I replace the ceramics and the micas. Now back to my color problem. What do you guys suggest?

OK adjusted L704 and was able to fix the rolling rainbow bars I now have color but the colors on the color bar pattern are all wrong. I tried messing with the tint but it did not give me the correct colors but did change the colors.

Could you post a picture of the color bars as they are now?

Here is what it looks like now note the blue on the far right is very dark because the blue knob wasnt turned up all the way

done

Black and white looks fine. I did accidentally adjust T704 thinking it was L704 at one point.

Your picture on that set looks really good. Nice job.. How is the picture on a ota converter?

There is a lot of magenta/purplish color and certain things but you can make out skin tones and some objects. And a bit of noise in the picture but reasonably clear.

If you disturbed T704, you threw off the chroma circuit alignment which is responsible for making the correct colors appear on the screen. Hook up the color bar gen and look at the screen with a mirror while adjusting the top and bottom section of T704 till the bars look right.There is also a chroma alignment procedure in the service manual, if you feel like doing it the hard way. Make sure the tint control is in the middle when doing T704 adjustments, or you'll have limited tint range when you're done.

Once you've got the bars looking nominally good, get a regular pic on screen showing people's flesh tones. Set the tint control mid-range. If the flesh tones are too green or too purple, tweak the burst phase adjustment T703. It shouldn't take more than 1/8 turn or so either direction get correct flesh tone.
Back in the day, flesh tone was the standard reference for centering the tint range.

OK adjusted T704 and it looks great. I still need to do some convergence adjustments. Here is a picture of what I have now. Is there any problems with any of the bars to any of you?

One more thing. Would it be a bad idea to use this as my daily watcher? All guns test great and the life test is good.

One more thing. Would it be a bad idea to use this as my daily watcher? All guns test great and the life test is good.

You should be able to use the set. Keep a eye on the line voltage. This set was designed to run on 117v ac. and you DO NOT want to run the set any higher than 117v ac. It can cause problems with the horz circuit and burn out tubes.

OK adjusted T704 and it looks great. I still need to do some convergence adjustments. Here is a picture of what I have now. Is there any problems with any of the bars to any of you?

image looks really tilted. Perhaps adjust the yoke?

Those are good color bars.

Before messing with convergence, I'd look at a crosshatch test pattern (or dot pattern) to judge whether it really needs improvement. Read about convergence in the manuals. Convergence is a multi-step procedure, not just one little tweak. On a color "roundie," it's difficult to get perfect convergence around the edges of the screen.

You can also look at regular programming to judge convergence. Look at the edge areas of the screen -- left, right, top, bottom -- and note whether there is "color fringing" around the edges of objects. This may be more obvious where there's lettering on the screen.

Some small amount of mis-convergence is pretty common in my experience. Ask yourself if your picture would bother you in everyday watching. If the answer is "not really," you could skip convergence for the time being. If your convergence is already pretty good, and you screw it up with hasty adjustments, it could be hard to make it that good again.

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

Kind of seems like I just need the dynamic convergence a lot. The line voltage coming from my cheater cord that came with the TV is reading 122v is that too high? If so how can I fix that? Will degauss the screen again and fix the tilt.

I must also note that there is a lot of noise distortion in the picture. I tried messing with the fine tuning but no luck. Should I do a color purity and dynamic convergence the red line is a bit higher when the blue and green are both one line.

One other thing I have tried degaussing the set atleast 5 or 6 times and I still cannot get a little bit of yellow to go away on the bottom right of the red screen. I am using a junk tv degaussing coil.

Kind of seems like I just need the dynamic convergence a lot. The line voltage coming from my cheater cord that came with the TV is reading 122v is that too high? If so how can I fix that? Will degauss the screen again and fix the tilt.
Yes, That is to high. You need to find a variable auto transformer.{ variac}
Running your set 0n 122v could raise the horz output tube cathode current, And melt down the fly back. I know it sounds stupid that a difference of 5 volts could damage the set but it can. To correct the tilt, Just turn the yoke when looking at a crosshatch. You will see what he means.

What would be considered minimum dangerous to the set? 119v? or not any higher than 115?

Here is a picture of my variac. This unit is 20 yo and is rated at 10 amps.

I really dont have the money for a variac. Is there any other possible alternatives?

What would be considered minimum dangerous to the set? 119v? or not any higher than 115?
Start with 115 and see how the picture is. I run my color set's at 117 volts and have not any problems with them. Even the newer color roundies like 117v, And they are rated at 120v. Your 7 is 57 years old. You have to look at her as a fussy old lady. What is going to be the next set you restore?

I think I'd like either a DuMont B&W roundie or an RCA ctc-5 Blonde Whitby. Back to my previous question. Are there any temporary solutions to reducing the ac line output?

I really dont have the money for a variac. Is there any other possible alternatives?
A thermistor surge resistor on one side of the ac line would help. but you really need a variac. It is as important as a volt meter when working on vintage tv.

Hmmm, OK I will try to find a cheap variac. Does anyone here have a variac I could take off their hands?

I've been running a CTC-15 clone as a daily driver straight from the line for about 5 years. The first two were in an area where the line voltage ran high probably 120-125, since then it is usually 117 give or take 6 volts. I've never had a problem with the fly going into over-current....Granted I did monitor and dip the cathode current by adjusting the linearity coil (which is probably a better way to control it than a variac).

If you are worried about overheating the fly adjust the lin. coil for min H out Tube cathode current and leave the HV cage door open for ventilation.

I dont see a linearity coil but I do see a horizontal efficiency coil that looks like it is connected to pin 3 which is the cathode on the H out tube. Should I adjust that one?

Swizzy-

Look up "line bucking transformer" or similar. If I remember right, it is a setup where you use something like a 6-volt, 4-amp output (in this case) transformer in a wiring setup where the six volts gets subtracted from the input (122 volts in your case). Such a transformer should cost a lot less than a Variac, for ongoing use of your set.

Hmm a bucking transformer seems like a handful but I might give it a shot. But it says that it will lower the voltage from 120 to 110v isn't that too low?

I've been running a CTC-15 clone as a daily driver straight from the line for about 5 years. The first two were in an area where the line voltage ran high probably 120-125, since then it is usually 117 give or take 6 volts. I've never had a problem with the fly going into over-current....Granted I did monitor and dip the cathode current by adjusting the linearity coil (which is probably a better way to control it than a variac).

If you are worried about overheating the fly adjust the lin. coil for min H out Tube cathode current and leave the HV cage door open for ventilation.

You are right. The cathode current must be adjusted for proper dip. If this is not done, The current will run high no matter what the line voltage is. Still, Why beat on the set if you don't have too. He want's to use the set as a daily driver and the variac will give him some added protection. Running the set at the line voltage it is rated at.

You could also add a PC cooling fan, maybe attach it to a part of the chassis that outputs ~6 volts DC. that would run the fan at half speed and keep it nice and quiet, and keep the TV running nice and cool.

It is labeled Horizontal efficiency in some sets, H linearity in others. Sams horizontal adjustment procedure and schematic should list max safe current and how to adjust....Skip the osc. adjustment and the more complex HV reg adjustments unless the current can't be reduced, or those stages show signs of misadjustment.

You are right. The cathode current must be adjusted for proper dip. If this is not done, The current will run high no matter what the line voltage is. Still, Why beat on the set if you don't have too. He want's to use the set as a daily driver and the variac will give him some added protection. Running the set at the line voltage it is rated at.

I'm not telling him to beat up his set, just noting my observation that MY set that has been in regular often heavy use since I restored it has done fine without any line input voltage control....Heck the cathode current was running WELL below the max safe value when adjusted running on high line voltage.

In many places the line voltage fluctuates so if you truly want to get OCD on line voltage get a VRT/saturable reactor/(insert other aliases for it here) isolation transformer that puts out a constant 120V, and buck that down......
I've been approaching that setup recently. The place I've lived in for the last few years has intermittent sudden brief and rapidly reoccurring voltage dips that cause highly annoying blooming. I've been using a 120V out VRT to regulate out these dips, and on the '71 Zenith I've been using it on I've been contemplating using a variac or bucking transformer with it so I can dial in the vertical over scan to minimum.

IMHO the best way to power a low voltage DC fan in a TV set is to connect a bridge rectifier to the heaters and a filter cap to the bridge. Then depending on the DC voltage it puts out how quiet the fan needs to be and the air flow desired select either a 5 or 12V fan.

Going to just try a bucking transformer. My AC is stable at 120.6v and rarely moves down a volt. What exact transformer should I get for the bucking transformer? I thought I heard a 2.2kva one was right? Also planning on refinishing the cabinet on Sunday after I build the bucking transformer Saturday.

Would this one work? Secondary out is 10v so If I buck it the output will be 110v right? Or is that too low or am I wrong about my theory? http://www.skycraftsurplus.com/f6-10tfmr10vct120pri.aspx

Electronic m I am sorry for the poor choice of words to get my point across.

Hey Roundscreen would it be OK if I ran the set just for about an hour right now?

You have been running your set to repair it. So I think it should be ok. What I do when working on a set is put my hand on the fly back tire to feel how warm it is getting. If it feels warmer than the power transformer, Shut the set down. If you do this make sure you discharge the hi voltage first. You have had to discharge the hi voltage before to remove the chassis, But still be careful.

Would this one work? Secondary out is 10v so If I buck it the output will be 110v right? Or is that too low or am I wrong about my theory? http://www.skycraftsurplus.com/f6-10tfmr10vct120pri.aspx
Since the secondary is center-tapped (5V either side of center), you can use half the winding for 5V of bucking if you wish.

Alright will do. One thing I've noticed that my horizontal hold is very bad when I first turn the set on but then 5 minutes later it gets stable. What is going on?

What about the ampereage? That one runs at 3 amps is that ok?

Alright will do. One thing I've noticed that my horizontal hold is very bad when I first turn the set on but then 5 minutes later it gets stable. What is going on?
Replace the 6cg7 and see if that helps

Replaced it twice once with another RCA used one I had that didn't work so then I put a Nos sylvania tube in and still no luck. Horizontal has been a big problem since the beginning. Is the high line voltage causing this?

The best I can tell you is I have never seen high line voltage cause a drift problem.
Take your volt meter and measure the heater voltage. Is it 6 volts?

I have no idea how to measure vacuum tube voltages... Can I use my DMM?

Yes you can use the dmm and Set it to ac volts.

OK just felt the donut/tire portion of the flyback warm but not even remotely close to the heat of the power transformer. But when I get to the middle where the tire gets to the support it gets a little hotter.

OK just felt the donut/tire portion of the flyback warm but not even remotely close to the heat of the power transformer. But when I get to the middle where the tire gets to the support it gets a little hotter.
Good. that is not to bad. How long has the set been on?

About 45 minutes.

Just keep an eye on it and no more that a hour at a time. Do you see any melted wax in the cage?

No more than an hour at a time with cooling fans? And decreased line volts? Absolutely no wax drippage what so ever the flyback looks beautiful.

Your set is doing good. When you get the line voltage where it belongs, You should be able to run it as long as you like.

At some point you will have to check the horz output tube cathode current.

That makes me very happy! You have been a BIG help roundscreen you helped me with my major horizontal problem and making sure my set will last me for years to come I just want to say a huge thanks to you. I will be sure to report back on my bucking transformer tomorrow or variac if I can get it cheap.

Will tackle that tomorrow. Might need a bit of help with that.

What about the ampereage? That one runs at 3 amps is that ok?

Back to my previous question... Is 3 amps ok in the transformer I will use for bucking?

Yikes! I didn't notice the xfmr you were looking at is only rated at 3 amps. No, that would give it very little 'headroom' since the TV draws pretty close to 3 amps.
You may not need bucking at all. First measure the heater voltage as Roundsreen suggested.

Well against my better judgement on money I just decided to get a variac. It is safer and a lot less complicated. Horizontal hold for the first 10 minutes is still a problem. But at least I am being nice to the set and giving it proper line voltage. Going to refinish the cabinet tomorrow.

Ok this horizontal hold problem is really starting to piss me off. I have to wait at least 20 minutes before I can use the damn thing. This has plagued me since the start of this restoration and quite frankly I am sick of it. I've replaced all but one capacitor on the horizontal board it is a ceramic cap. Heater voltage on 6CG7 is fine. I want this fixed for good. How can I do this? Please help!

I thought it went away after you replaced the mica caps.. Now it's back?

At first it was good but now it is terrible it has been about a week since I replaced all but one mica cap

did you ever check that resistor I mentioned pages ago?

Ok this horizontal hold problem is really starting to piss me off. I have to wait at least 20 minutes before I can use the damn thing. This has plagued me since the start of this restoration and quite frankly I am sick of it. I've replaced all but one capacitor on the horizontal board it is a ceramic cap. Heater voltage on 6CG7 is fine. I want this fixed for good. How can I do this? Please help!

Sorry I was not around yesterday, A good friend passed away.
If you start getting pissed off, Take a break from the set. The problem may be you replaced a mica cap with a ceramic cap. Try and find a film cap and replace it again. Double check your work. See if you missed something. Also can you adjust the horz hold to a normal picture when the set is cold? Most of us have been through the same thing, So you are not alone. It takes time to learn how to fix vintage TV.

Very sorry about your friend :( I still want to continue with the set I was just a little frustrated last night with other problems. I will check if I used Micas in the right place and ceramics in the right place. Can get a somewhat stable lock but my color goes all wonky. Also the picture swerves from left to right. Eventually I get full lock and great color after about 20 minutes of running the set.

Yes Dave the 68K resistor checked fine when I tested it with one leg unsoldered from the board.

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?

sometimes things get better with use, I have heard theories that could be moisture being driven out with heat. So try using it and see if it continues to improve.

If not, you need to determine if its an osc prob or a sync pulse prob.
you could try monitoring the voltages of the sync sep tube to see if anything is changing from when 1st turned on to when it settles down.

Will keep an eye on it. Starting to refinish the cabinet today.

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.

Is the problem worse at reduced line voltage, and better at the voltage that you were running before you got the Variac?

jr

Worse at 115v but a lot better at 117v

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?