My CTC-16XL Project.

[Yamamaya42]

Originally Posted by old_tv_nut

"Slight ghosting image" isn't a specific enough comment to guess about. Can't tell how much is "slight," is it really a ghost or more of a smear or ringing, etc. - would have to see it. In any case, your video amplifier and the coupling capacitor would not cause it. I think you should wait to do more nitpicking after the cataract is removed.

For the cataract, i have been waiting for the right kind of weekend, one where both I and my friend are free, ( i need help with it ) and it's not raining and it's hot and sunny, so far this year we have be cooler than normal, but it looks like we may hit 100f next weekend, so we may try then.

as far as what I'm seeing.
https://imgur.com/ifbHDAy
you can really see it there
and slightly here
https://imgur.com/c9mwBtj
not sure what that is.

[old_tv_nut]

I don't see anything I would call a ghost. A little misconvergence, maybe some spot blooming on the bright lines, and what appears to be some cross-color (the ragged-looking color mostly to the left of the vertical lines) that should go away when you turn the color all the way down.

Don't obsess over little things until the major things are fixed. It's easy to get hypercritical and expect an analog set to look like a computer monitor. It won't. It is normally watched from ten feet away, so the technician's view with nose pressed against the glass will just drive you crazy trying to reach perfection.

[Yamamaya42]

Originally Posted by old_tv_nut

I don't see anything I would call a ghost. A little misconvergence, maybe some spot blooming on the bright lines, and what appears to be some cross-color (the ragged-looking color mostly to the left of the vertical lines) that should go away when you turn the color all the way down.

Don't obsess over little things until the major things are fixed. It's easy to get hypercritical and expect an analog set to look like a computer monitor. It won't. It is normally watched from ten feet away, so the technician's view with nose pressed against the glass will just drive you crazy trying to reach perfection.

https://imgur.com/fWo0QBs

this is what i mean
this shadow should not be there
i can find a good image someplace, but will take time
edit...
digital capture of source
https://imgur.com/CRUNIvo
this is what I mean

[old_tv_nut]

Oh, now I gotcha. I would call that a strong negative ghost. I was looking for minor stuff and ignored that as part of the graphics image. Oops! My bad.

The only thing that comes to mind is a bad termination on the luminance delay line.
Check that L14 is not open. If L14 is ok, check resistors in that area.

[Yamamaya42]

Originally Posted by old_tv_nut

Oh, now I gotcha. I would call that a strong negative ghost. I was looking for minor stuff and ignored that as part of the graphics image. Oops! My bad.

The only thing that comes to mind is a bad termination on the luminance delay line.
Check that L14 is not open. If L14 is ok, check resistors in that area.

L14 is ok,
its much less pronounced when i use another source as input. but still there.
it goes all the way back to the cathodes of V6 and C1-c via line 64 ( still original ) checked voltage there and was 35v
i did intend to replace that cap, but did not think it was that important.
Its odd that it seems to be more pronounced with some input sources than others, that is what made me suspect an impedance problem.
just to be sure, i could replace that cap, and the resistors in the area with 1% to see what happens.

[dtvmcdonald]

That's a long time! Thus, one suspects reflections in the cable from the source.

Find a source you can connect to the set with a very short, less than one foot, cable.

If your signal is bigger than needed, as a test try a 6 to 10 dB attenuator with correct resistive
matching at the receiver and see if the ghost gets much weaker.

[old_tv_nut]

Don't worry about 1% tolerances - this is a much greater effect.

As dtvmcdonald says, this could be a problem in your source.

But to make sure, I would check that the complete path through R64 and L13 is Ok (2200 ohms), and check C1C by temporarily bridging an approximately 40 microfarad capacitor from line 64 to ground. Then, if the problem is still there, investigate your source.

As dtvmcdonald says, this could be a mistermination of a long cable somewhere, but I think it would have to be a really long cable, like 200meters (656 feet). The luma delay line is roughly one microsecond delay. A back and forth again echo time would be twice that. If you assume the visible width of your picture is about 50 microseconds, the ghost is indeed about two microseconds.

[Yamamaya42]

Originally Posted by old_tv_nut

Don't worry about 1% tolerances - this is a much greater effect.

As dtvmcdonald says, this could be a problem in your source.

But to make sure, I would check that the complete path through R64 and L13 is Ok (2200 ohms), and check C1C by temporarily bridging an approximately 40 microfarad capacitor from line 64 to ground. Then, if the problem is still there, investigate your source.

As dtvmcdonald says, this could be a mistermination of a long cable somewhere, but I think it would have to be a really long cable, like 200meters (656 feet). The luma delay line is roughly one microsecond delay. A back and forth again echo time would be twice that. If you assume the visible width of your picture is about 50 microseconds, the ghost is indeed about two microseconds.

I have 56uf caps that I have not used yet, 350v would that be Ok replacement for C1C? or is the 40uf critical?

the cable from video amp to TV is made from thick high quality component video cable and is 5 feet long, over 1/4 inch thick copper conductor solid.
https://imgur.com/1NUU8mC
however the cable to the video amp is cheap and lightweight, i will prob replace it with a 2 foot piece of the same high grade type.

[old_tv_nut]

Yes, 56 uF 350v would be OK for a quick test, as the voltage there is only 25 volts, and the tolerance on multisection electrolytics is normally very wide, especially on the high side. If it works, just use it, or look for a lower-voltage rated one for final replacement. There might be some concern about a 350v rated cap not forming completely and therefore producing less capacitance, but I really don't know at what point of over-rating you would get any problems. (I never ran into such a problem in designing gear, because we never used grossly over-rated caps due to unnecessary expense.) So, I say just try it.

A 5 foot coaxial cable is not long enough to generate that much delay. RG59 coax, for example, has a propagation speed of about 2/3 of the speed of light, so 5 feet would be only 5 nanoseconds. A reflection would be delayed 10 nanoseconds, which would be invisibly close to the main signal.

[old_tv_nut]

FYI, the speed of propagation in a transmission line is determined by the amount of inductance and capacitance per unit length, and the matched impedance is determined by their ratio. The luminance delay line has a coiled conductor to increase the inductance compared to a regular coax, and the conductor is wound over a grounded conducting sheet to increast the capacitance. The result compared to coax is much greater delay in a shorter, smaller device. An increased inductance / capacitance ratio also makes the impedance higher than 75 ohms, to work better with typical tube circuits. In this case the line is apparently designed for 1800 ohms (R64 in parallel with R63.) When a transmission line is matched on both ends, there is a 6 dB loss. This sort of synthetic delay line usually has some added attenuation at high frequencies and is not perfectly matched at high frequencies either. These shortcomings are compensated by the various coils you see on the output end.

[Yamamaya42]

Originally Posted by old_tv_nut

FYI, the speed of propagation in a transmission line is determined by the amount of inductance and capacitance per unit length, and the matched impedance is determined by their ratio. The luminance delay line has a coiled conductor to increase the inductance compared to a regular coax, and the conductor is wound over a grounded conducting sheet to increast the capacitance. The result compared to coax is much greater delay in a shorter, smaller device. An increased inductance / capacitance ratio also makes the impedance higher than 75 ohms, to work better with typical tube circuits. In this case the line is apparently designed for 1800 ohms (R64 in parallel with R63.) When a transmission line is matched on both ends, there is a 6 dB loss. This sort of synthetic delay line usually has some added attenuation at high frequencies and is not perfectly matched at high frequencies either. These shortcomings are compensated by the various coils you see on the output end.

The delay lines for these sets seems to be another impossible thing to find, should someone ever need to replace one.
I remember being amazed when i started to see them made out of quartz in newer sets, still cant quite get my head around how that works.

[old_tv_nut]

The quartz lines are not for the ~1 microsecond difference between luminance and chrominance, but for a one-scan-line delay, either for chroma phase error cancellation (in PAL) or comb filtering (in NTSC). The quartz lines work by ultrasonic sound to propagate the signal, which is much slower than an electromagnetic wave.

[Yamamaya42]

update, I DO see some color via the tuner, weak and sloppy ( smeared and bleeding ) , nothing as exact and sharp ( on target ) with the injected video.

[Yamamaya42]

best I can get through the tuner / IF

https://imgur.com/dGHxwXP
https://imgur.com/Z9N1j2H
pretty ugly

no where near a clean color with direct input.

We are going to attempt to fix the cataract this sat, I'm going to leave it in tuner input for now, so when i put the CRT back in i can use the bar dot generator to try and align the convergence, then switch back to direct video.

[Yamamaya42]

Cataract repair successful!

Start
https://imgur.com/MFKZ9DT

safety glass removed.
https://imgur.com/OK4HM7c
https://imgur.com/u37ddqC

problem causing krud
https://imgur.com/XEGMLIN

repair complete
https://imgur.com/YkDt2YL
2 OEM legs were lost over the years in storage, once done, they will be all 4 matching.

I did have a slight complication, a secondary CATaract had to be removed before it could be completed.
https://imgur.com/Cub0Mxk

Now I'm ready for purity and convergence.

the one thing i really don't get is...
in this video, https://www.youtube.com/watch?v=dQ_i_8rTIR4
shango066 points out a "flaw" on the surface of the CRT at about 8:30, i saw the exact same mark on mine
is this on all of them? some of them? very odd, unless it is a deliberate mark.