My 11 year old son's Admiral 30A1 restoration project

[Dave S]

That is so cool, Tim. My daughter built a crystal radio a few years ago when she was 18, but working on TVs is a whole 'nother world. I hope your son continues to enjoy the hobby.

[Kamakiri]

SUCCESS!!!

Found a blown fuse in the HV cage, and we got full bright screen and a picture!!! The horizontal time base was screwed up (there were 4 images) and as I was adjusting the range control, the vertical sweep eventually gave out. Time to search out the vertical problem, but hey, it's holding HV like a champ with a SUPER bright raster!!!

Odd thing is that we couldn't get sound once we had the HV fuse replaced. Back to the drawing board tomorrow

[kramden66]

Captain be aware early admirals can be known for ert osc and output transformers going bad , i'd check the resistance on them and if ok it is somewhere else
mike

[Kamakiri]

Originally Posted by kramden66

Captain be aware early admirals can be known for ert osc and output transformers going bad , i'd check the resistance on them and if ok it is somewhere else
mike

That was my first thought. The picture started "winking" out, until it finally collapsed.

[Kamakiri]

So here's where we're at.....something peculiar.

Vertical output transformer ohmed out fine as it turns out, I could have sworn that would have been the issue.

Now....

HV is great, but no vertical sweep, and hotizontal sweep is ONLY evident on channels that have a signal. If there's no signal, the screen goes dark. We checked and replaced a couple resistors in the vertical oscillator circuit that had drifted high, but nothing that was either shorted or open.

[Kamakiri]

By the way, the cabinet is back from refinishing. Looks pretty darn good!

[Kevin Kuehn]

Of course you've tried wiggling and swapping the vertical oscillator and output tubes, and cleaned sockets. You can check pin voltages against Sams, or if it were mine I'd have my nosy scope probe in there to see what's really going on.

That cabinet has some very cool grain patterns going on.

[Sandy G]

Something he can be PROUD of from now on... Wish MY old man had tried to have done something like that with/for me..

[stromberg67]

Originally Posted by Sandy G

Something he can be PROUD of from now on... Wish MY old man had tried to have done something like that with/for me..

Yes, Sandy I know only too well about that kind of thing. I was never encouraged in my electronics hobby by either parent, and when I dragged home a radio or TV to work on, it was always "junk". Otherwise, they were good to me. We did manage to overcome, didn't we !
So happy that many parents aren't like that.
Kevin

[jr_tech]

If voltages appear to be correct, I would be checking in the area of the sync amp/separator/inverter/network... possibly a component has failed that kills the vertical oscillation as well as making the horizontal oscillation "conditional"

jr

[Kevin Kuehn]

Regarding you're missing audio - don't forget you do need the audio cable plugged in between the main and power supply/audio amp chassis.

[Kamakiri]

Nick missed that on last power up, actually. Audio's there now, although it seems as if it's not as strong as it was before.

[Boobtubeman]

Thats why im so hell bent on finding a tv like the one in my avatar... Was the first tv me and my dad ever worked on together...

SR

[Kamakiri]

All righty! Back on this one with my son

Found that this big resistor bought the farm, so it needs replacement. As pictured, the top wire was dismounted for testing.

Now here's the weird thing.....only two wires are hooked up on it which leads me to believe that only one value of the resistor is used. However, the diagram shows all three with the other ends just loose in space??

Question is, do I just order the one section that's used, or for some reason, all three?

I'm 99% sure I know the answer, but it never hurts to double check......

[old_coot88]

I would go with the value that was used `as found` and disregard the unused taps.