My Brand New CTC-7!

[DaveWM]

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

[dtvmcdonald]

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.

[SwizzyMan]

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

[dtvmcdonald]

Originally Posted by SwizzyMan

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!

[SwizzyMan]

Sorry about that

[SwizzyMan]

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.

[DaveWM]

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).

[DaveWM]

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

[SwizzyMan]

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.

[DaveWM]

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.

[SwizzyMan]

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

[DaveWM]

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.

[SwizzyMan]

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

[DaveWM]

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

[SwizzyMan]

Yes sir