That's sort of two fold, in RF input mode, there is shadows that move with fine tuning, but are mostly seen in the color, if color is turned down, no shadow movement is seen, but there is a shadow also seen in the luminescence that does not move. This is also seen in direct A/V input.

I have known about the set having IF problems that had an effect on the color ( mostly red ) thus set the auto bypass circuit in it via a signal relay at TP1 Point B, direct input does look much cleaner, but still has the same shadow to the right as IF input, if I ever can get the IF aligned correctly someday I can remove the mod. :(

Shorting it won't be an issue really, :)
I essentially have an exact copy tube in the GE CTC-15ish clone, that I can take to work and rig up under microscope and make sure it's OK before I put it in.

OK - definitely in the video section then.

AHHHH! I just found something I missed before, even though the 1st/2nd video amp tube has the shield on it, it is NOT being grounded.

the tab must have broke, or bent and I missed it.
gonna have to fix it.
No telling what kinda mess it could be causing...

Delay line bypass rig made, will try it this weekend.

https://imgur.com/IwoAhCB

grounding the shield did not make much of a difference. :no:

I hope that improves it for you. I know what it is to go after issues one at a time and when you see little to no improvement with each one, but they do add up.

The 21" Zenith I restored was that way. Original trouble started with a shorted sync/sound detector diode (not before sending me on a journey through the Zenith-unique sync circuit) and extreme vertical and convergence issues, which I learned alot from.

At the beginning, I could not imagine it ever being Zenith-bright/sharp. After several weeks, looking back made me realize how easy one could give up before its working as it should. Its just physics!

Well, the bypass idea did NOT WORK! :no::tears:
fail BIG TIME!!

https://i.imgur.com/6P12EZj.jpg
caused an echo image, which was ironically at about the same place that I had be seeing the shadow image, so who knows, it may BE delay line related, I will have to wait till the next time I have the chassis out to know for sure, I still wish I i could find a NOS Miller cross reference chart someplace, as IF i have to replace it, I'm sure that site has one I'm just not sure WHICH one,

In the mean time, I'm gonna work on what I CAN do w/o pulling the chassis, as in getting the convergence as perfect as I can, I made a few mistakes in placing the parts on the, CRT neck, but it did not seem to matter much, I still cant get it the way I like it, I may never will, there are some original resistors on the convergence PCB that I intend to change next, that may help.

Aside from that, there is a moderate list of minor annoyances to hit next time I pull the chassis... heavy sigh! :tears:

D'oh. Now that I look again, this is to be expected because the delay line is not driven from a low impedance (cathode), but high impedance (plate). To do the check you wanted to try, both ends of the delay line should be disconnected and then the jumper put in its place. You are seeing multiple reflections in the delay line when it is still attached.

If the shadow image without the jumper is at the same spacing as the one you see with the jumper, that is the same triple transit effect. This circuit does not necessarily terminate the input of the delay line correctly. Therefore, if the output termination is not perfect (or the delay line impedance is not nominal at all frequencies), some energy may be reflected back to the input and will not be damped there and will reflect again and return back to the output ("triple transit").

This tells you that if none of the components are out-and-out defective, the set may be operating within factory tolerances, and they all were subject to a bit of triple transient effects.

At this point, the delay line is no longer very suspect. Instead some trial and error variation in the output load components may improve things. L13, L14, R63, R64, and maybe L15 can all have an effect. But don't be too surprised if you find that you can't make it much better, and mainly worse. The fact that R64 is the only 5% resistor in the area is a hint. You could try tuning the L's (to larger inductance only) by bringing a core or some iron on a stick next to them. If you had a stock of peaking coils, you could try various values.

more: You could try replacing the peaking coils even if none of them are open, in case they have shorted turns instead. But I don't know if that was ever a common failure mode.

I do know for a fact that the delay line was roughly handled when I got the set, I'm not sure if it was really damaged or not, but it was NOT treated well at all, left hanging loose with only the IF end connected, I wish I had pictures of it, it took me quite a while to work out where all the loose wires to the color PCB went. :tears:

however, L13 was damaged, ceramic broken on the leads, more than ½ way, but still had continuity, so I assumed it to be OK and suck silicone on it and put it back in.
This may be a source of a problem, no idea, :( but as luck would have it, I have just found an exact replacement for it, and will come who knows when :/

Another possible problem. however I doubt it, that when I put it together, I had no real visual reference on HOW to do it, unlike I do now.

example, how it's done in the GE RCA clone, https://i.imgur.com/FxjBWaj.jpg

you can clearly see the heavy wire going down that is grounding the delay line, in my CTC-16, that was GONE! all that was there was the grounding solder point on the DL, and since I was unsure where to ground it to, i used a piece of wire ( not as thick as seen in the pic ) that runs to a ground point to the ends on the color PCB.

I doubt that this is a problem, but who knows :sigh:
Is the DL damaged , no way to tell w/o getting it out and looking at it under a scope :/
there has to be some way to find a cross for it, if it is.

As for the peaking coils, some of those oddball sizes will be hard to find. :tears: I got lucky with L13 (72 uh ) who knows, may get lucky again! :D

Grounding the delay line differently than originally could cause some trouble.

It would be reasonable to use series combinations of more readily available coil values to make a replacement for the odd peaking coil values. The specification of odd values is a hint that they may be critical, just like the 5% resistor.

Peaking value coils are never critical. In fact, its sort of silly worrying
much about just the value, unless you can get a for certain absolutely exactly original
factory model coil.

You see, these thing have capacitance across them and thus are parallel tuned circuits. Whether they are used in series with the signal or as a plate load, that resonant frequency matters.

And the "standard replacements" listed are often, while close in low frequency
inductance, way pff in parallel resonance. That can make for a bad picture.

I have an RCA CT-100 color TV with lots of peaking coils that are potted in something white that corrodes them. In fact though some of mine were bad, none were
so bad I was unable to unwind a few turns and get measurements of inductance and resonance. I had to experiment to get the waveforms to look right. I bought
two or three coils for each replacement. The best inductance value varied
up to 35% from spec. Most were noncritical but a couple were critical.

Putting coils in series thus generally simply won't better than just getting close.

on the "to do " list next time the chassis is out.

Replace R70 (out of tol) , & C31,R71 just to be sure, they are most likely OK , but new parts won't hurt, hopefully this can cure the retrace problem.

Inspect delay line VERY closely, checking for any damage at the grounding point, and see if repair/ replace needed, re-connect ground to OEM position, similar to as seen in GE chassis. Replace L13 that had been slightly damaged with NOS RCA part. Replace R64 with new 2% part, it's most likely OK, but while I have it out, why not, inspect L15/L15, they are on the topside of the PCB, and unlikely to be bad.

Check remaining original orange drop caps for leakiness.
Replace focus resistor & cap.
Fix the damn loose connection on the heater pin on the socket of the HOT. :(

I did manage to view the entire DVD , Watchmen Director's Cut, this weekend with it, and I saw no macrovision problems whatsoever, I'm not sure if it was because of the player used, or the DVD, or because I was using direct A/V input, but it was very stable, no problems at all.

Damn, L13 will be arriving surprisingly fast, It was shipped from within Texas, only 10 hours from here, It will be here Thursday.

The focus resistor, however, is coming from REEDLEY, CA, that will take a wile :(

does the 130 PF cap in the focus circuit really wear out that much and need replacing?

new L13 has arrived, no other parts yet, it does not look like the old one, but that is not unexpected,

https://i.imgur.com/pVTY6tn.jpg

found an old pic of the underside with the delay line and coil
https://i.imgur.com/1XZjvKL.jpg
you can see how I grounded it, and L13. (but not the damage to it )

waiting for the other parts

Well, USPS, “says” that the 66meg focus resistor is in the mailbox, but I won't fall for that again after the thermistor fiasco, I won't believe it until it's in my hands.

FEDEX says that the replacement for the 130pf cap in the focus circuit will come Friday, now there seems to be some flexibility on the value of a usable replacement, CTC 10-16 SAMs list no sub for it other than the RCA part# @130pf, but in the CTC 20, a 120pf is listed as a replacement, however, in the GE CTC 15 & 1/5 clone, it lists a 150pf as one, which I have used successfully, and since the focus circuits are all identical for the most part in all of them, I got another 150pf / 15kv for CTC-16XL.


Meaning that now, I should have have all the parts needed to do all the minor updated to my RCA that I had been wanting to do, including removing that black wire I have grounding the delay line, and grounding to the nearest gnd point via a heavy lead from a power resistor, the thicker, the better.

But, I'm still debating on to try it this weekend or to try and get the GE clone downstairs, setup and converged.
It's still too heavy for me to move on my own, so I'd have to bribe someone to help, or take it apart, IE remove the CRT from the cabinet and take them down separately, ( which I really don't want to do ).

The specs say a 21FJP22 is 43lbs, the cabinet rough guess is 20lbs? Separately, easy enough for one person to move, even with a shoulder that's healing fro surgery, together,, NOT... the chassis is very light compared to the CTC-16XL, and even the FADA rca 630ts clone, I was surprised at how light it was, like someone pointed out, GE= Good Enough.

Still not sure which way I'll go this weekend. :(

with them side by side now, i can really see the difference between the 21fjp22 and the 21fjp22A.

In the greens mostly. but I;m not sure if that is just a difference in the color/ video circuits of the CTC-15/GE and the 16XL.

About the focus circuit, I have seen it said that the 66meg (6kv) resistor gets hammered a lot and often drifts out of spec, I saw this in the GE-CTC-15 clone, but what about the 130pf ceramic cap? Are they pretty stable, or need attention also sometimes?

I've read a case or 2 of that ceramic cap going open-ish (not producing a good null on the eye tube of a restored 60's cap tester). But on average they are pretty reliable.

Then I don't think its bad in my 16xl, but I'm sure the resistor is worn, not that I CAN'T bring it into focus, but in order to do so, I'm almost at the limit of travel on the focus coil, so it can use a new one I'm sure.

Just another thing to add to the list next time I take it apart.

So far, my CTC-16XL has been going very well with hourly weekend usage, no major problems seen yet, other then the minor annoyances mentioned before.

So, until something pops up to urge me to pull it apart, I wont sweat the small stuff, but I may touch up convergence, it's a bit off again.
As stated before, on the list of minor stuff.

Replace the 66m focus resistor that seems to have drifted a bit.

Restore the grounding of the delay line to factory spec & put in new peaking coil to replace damaged one, ( though it may be OK, never hurts )

Replace resistors and cap on plate of video output, that gives vertical blanking. ( missed them when I restored it. )

That's about it.
:)

Good to hear this is coming along, considering my break from early color 21-fun (till I'm driven indoors by cold) I have nothing new to report.

A video posted by Shang066 https://www.youtube.com/watch?v=caS-GKl19KA highlights the desirability of an RCA CTC16XL and how its easier to diagnose than a Zenith 24NC31, which will requires advanced troubleshooting!~

For my CTC20, a few issues remain including focus taking a few minutes to dial in, sound issue due to PC board connection, it did take a replacement of all the electrolytics to fix the pesky sync issue.

I always had the opposite experience from Shango. When I get an unrestored Zenith it typically works for the most part as is and just needs a few caps changed and some tweaking to work good.

Most RCAs I've encountered have had bad grounds, burnt jumpers, bad sockets, bad boost rectifiers, burnt flyback tires and various other issues that have to be found by troubleshooting.

Zenith tvs were some of the best.

had a rather lucky mistake at work this week, of the many hundreds of PCBS built, they put the wrong parts on some, rather than a high power NPN transistor, they put a dual diode in, THIS one , https://www.mouser.com/datasheet/2/3..._D-2315355.pdf.
sice it was powered on and thus removed, it Can't be used in the correct location, and thus MUST be scrapped, and so I nabbed one from the scrap pile, as it seemed to be perfect for a horizontal phase detector when i should ever need one.

It's NOT damaged, Just can't be used as a " new virgin " part.

:D:banana:

did a convergence tweak today.

https://www.youtube.com/watch?v=I5jhol_pSRo

can never et the top R/G vert 100%, and the upper right corner has always been dicey, but the rest is VERY good!
https://i.imgur.com/Oza4xm3.jpg


I think i need new caps in my pattern generator...

vertical linearity is also a bit off :(

Vertical linearity errors can affect the convergence at the top or bottom. I think you will "converge" on better performance bit by bit.
:yes:

Yes, I can see how it can, as its fed directly off the cathode of the Vert output via a cap resistor network, (50uf/5.6k) , but I MAY have screwed the pooch a bit here, :(, I did not replace c4 with an exact 50uf 150v cap like as listed, but with a 56uf 200v.
Will that 6uf throw things off that much?

My guess is it's not critical because it's not in the feedback loop for the vertical circuit.
Edit: besides, electrolytic tolerance is so wide it would never be designed into a spot that could have a large influence. It generally just needs to be big enough.

but it does go down (pt 51) to pin 2 on the convergence assy plug, which goes directly to r27 R-G vert lines top, I have always wondered if that 56uf cap was a mistake. :(

Again, I think its only job is to be big enough. If you have a spare 50 microfarad of the right voltage rating, you could tack it across C4 to see if even doubling the value does anything.

If I'm following the circuit correctly, the total resistive load on C4 is about 100 ohms. This corresponds to a cutoff frequency of about 32 Hz, which should be good to carry the 60 Hz sawtooth shown on pin 2 of the convergence connector. Increasing C4 should only make it work better.

I tweaked the vertical linearity and it mad a minor dif at the top, right top corner is still worst, may never get that perfect.

THIS time I know the placement of the neck parts are right, as i used the GE CTC-15 clone as guide.
https://i.imgur.com/jN1Qj1g.jpg
CTC-16

https://i.imgur.com/kjHeZ2J.jpg

clone

convergence yoke just inside the black area, purity magnets, red area, blue lat, just beyond that.

I may play with it more this weekend, but i NEVER did replace ALL the resistors on the convergence PCB, caps, the selenium device, but not all resistors, and they DO get hammered, this may be a source of trouble..

Just a note: on my CTC-5 adjusting the V lin could not get it there, but replacing the vertical tubes improved the linearity a little bit and the top convergence quite a bit. No guarantees, but new tubes may be worth a try.

easy enough to try, its only 1 tube 6GF7A found a NOS for $$9.75.

unlike the HOT, which the audiophiles have driven up to insane prices... :tears:

While I wait for the NOS 6GF7A to come, next week, or so the tracking says, I have decided to re build the convergence PCB (again), THIS TIME, making sure to replace all resistors that were not replaced before with 5% metal film, and all caps with 5% Panasonic, not sure what caps are in there now, this SHOULD make some dif, I hope, not sure why I skipped the 100 ohm & 180 ohm resisters last time.
Over all cost, $13, costing more for shipping 250 miles from Mouser than the parts, nothing new, but they get here in a day most of the time!

And shipped.
that's one of the good things about being so close to Mouser, always next day service!

So there will soon be all new parts on the Convergence PCB aside from the coils and Pots.

new parts are.
ECG120 Color TV Convergence Rectifier (on PCB,got in 2019)

ECQ-E6823JF3
ECQ-E2563KFB
ECQ-E2104JF
ECW-FD2W124JQ
PR01000101000JR500 x3
PR01000101800JR500
PR01000102700JR500

No clue if this will make any difference at all, but you never know.

Definitely a Resistor problem :yes: don't know WHY i did not change them when I put the diode pack and other caps in :eek:

did a quick check while i had nothing better to do.

1 of the 100 ohms checked at 106 (passable) another at 205 FAIL HARD!!
will wait till Friday night to rebuild the PCB, and the start the convergence process all over again, cause no doubt this will change everything.

If i had $1 for every time i have done the convergence process, I'd be a millionaire! :P

I really am curious just how much an overall effect this 1 bad resistor can really have.
https://i.imgur.com/exgm9RR.jpg
I know it all interacts with each other, but will that 1 bad resistor being over 100% off cause the center to be off ( static convergence) by being so far off?
I'm very eager to see how much it's going to change.
R220 was within tolerance, as was R218& R217, could not test R219 in circuit, as they are across coils.

The diodes are meant to keep the center adjustment constant when adjusting left or right, but I don't know how much that is affected when R221 and R220 are so imbalanced. Guess you will find out.

You could test this before you replace R221 - does the center remain constant when you adjust R25 and R28?

It always has to some degree if I remember, in fact, SAMs has doing static convergence a 2nd time in the procedure.
So I guess it WILL be changed by quite a bit!
I'm in for a fun night Friday! :)
SAMs steps.

static convergence
R-G Vert lines top
R-G Vert lines bottom
R-G Horz lines top
R-G Horz lines bottom
Blue Horz lines top
Blue Horz lines bottom
static convergence a 2nd
Blue Horz lines right
Blue Horz lines left
R-G Vert lines right
R-G Horz lines right
R-G Vert lines left
R-G Horz lines left
go crazy because you have just spent 2+ hours on this going round and round and you have a headache from looking directly at the the screen 3 inches away from your face because your glasses cause chromatic aberration making it even harder to get the silly thing set right! T_T