Admiral 20X1 frequency.

[Doug66]

I lost the vertical frequency and got a double pic on my Admiral. While trying to diagnose it, the horizontal frequency is now running to fast. I'm now at a loss. Do I need to diagnose each sweep section or start with the sync? Thanks in advance.

[Electronic M]

If the frequency is off you diagnose the sweep stage, if frequency is OK and you can get a single image that floats in both axes and can be made to roll both directions with hold adjustment you diagnose the sync.

Most sets horizontal is fairly easy to get on frequency by centering the hold pot and adjusting the synchroguide coils for correct frequency (for sync or single floating image if no sync from separator).

Also if you are using HDMI to AV converter that supports both NTSC and PAL or component video that supports progressive scan and resolutions about SD make sure your sources are configured for SD NTSC interlaced.

[Doug66]

Thanks for the advice. I've been working on the horizontal oscillator section and can now get a somewhat stable horizontal pic. However I'm back to my original problem. Vertical frequency too high. Already replaced vertical oscillator transformer and no improvement.

[Alex KL-1]

About the source, is good to test with another TV your source, for checking that Electronic_M said, to be 100% sure.

About the TV, if both V and H are twitchy/touchy, it must to be a common circuit cause, ie. from sync separator back (including video, IF, and RF). Bad sync separator, or bad aligment of the IF section (making bad video freq. response) are 2 of various possible causes.

[Electronic M]

Transformers usually don't effect the frequency in the vertical. It's usually capacitors and resistors that set vertical frequency. First check your work, it's rather easy to install a capacitor 10x or 1/10 the original value and that'll mess up frequency something fierce. If the caps are correct next check resistors measure within tolerance (probably 10% in a set like yours) and if higher than rater tolerance change them, if lower suspect a parallel resistance path and unhook one leg of the part to verify.....
If all that fails you can decade box engineer a new resistance or capacitance value to get correct frequency.

Back in highschool on my first TV restoration I moved cross country after the first recap and before I fixed a video issue. When I finally got video I had vertical like yours, the original bumblebee caps (didn't know how to read them back then and recapped off the Sam's manual) had been tossed months ago and I discovered that one vertical cap in the Sam's parts list was 10x what it was on the Sam's schematic (Sam's typos strike again)...I had no capacitors or money, but I had a bag of resistors from scrapped gear, and a decade box...I played around with raising and lowering various resistances until I found something that worked.

[Doug66]

I spent the last two evenings back on this set. I've got a good vertical lock but frequency is still off. Horizontal is pretty solid but does lose sync at times.

Some voltages are really messed up. Vertical oscillator tube plate pin 1 sb between 80 and 148V. I've got 38. I've put a new oscilator transformer in. Primary sb 160 and I measure 190 ohms.

Sync separator tube is really off. Plate SB 38V. I've got about114. Cathode pin 8 sb 2.2 and I've got 63.
All caps and resistors in these circuits have been replaced and measure in spec. So I'm now at a loss.

[old_tv_nut]

Regarding the sync separator plate - what kind of meter are you using? Could the pulsed nature of the signal be affecting it?

[Doug66]

I'm just using a basic digital meter. Do I need another type fir this?

[old_tv_nut]

Originally Posted by Doug66

I'm just using a basic digital meter. Do I need another type fir this?

I don't know for sure if your digital meter reads the correct DC average of a pulsed waveform (it probably does), but it is for certain that the original service info readings were made with an analog meter.