1959 zenith has no horz. hold?

[dieseljeep]

Originally Posted by old_coot88

Ditto here. But it was more like 99% of the time. And it was always a common cathode type. I honestly don't remember ever encountering or replacing a common-anode or series type, although the Boss kept all 3 types in stock, and in the caddy.

I remember using a series connected, but never a common anode. I think some Admirals used the series connected.
Admiral used the bullet shaped one, that was soldered in the pc board, where the 6AL5 would be.

[Tubejunke]

I have a 59 Space Command with the 18C24Q chassis that I am forced to part out if you need any parts. I'm not sure if it is the same general chassis that was common in Zenith sets of that time period, or if you have something completely different. Mine is a big 24" and lack of a test crt and thus a way to power the chassis and perform voltage checks prevented me from restoring vertical sweep a few years ago.

A recap and resistance/transformer/yoke checks didn't help, so the project is cancelled and the space is needed. Inversely, I would buy a "known good" chassis and put it in my set if I were to find one for sale. The set is great looking and the 24" crt with remote sort of make it a bit special, but seemingly valuless on the market. I would like to have it as a regular use set.

[radiotron]

Originally Posted by Tubejunke

I have a 59 Space Command with the 18C24Q chassis that I am forced to part out if you need any parts. I'm not sure if it is the same general chassis that was common in Zenith sets of that time period, or if you have something completely different. Mine is a big 24" and lack of a test crt and thus a way to power the chassis and perform voltage checks prevented me from restoring vertical sweep a few years ago.

A recap and resistance/transformer/yoke checks didn't help, so the project is cancelled and the space is needed. Inversely, I would buy a "known good" chassis and put it in my set if I were to find one for sale. The set is great looking and the 24" crt with remote sort of make it a bit special, but seemingly valuless on the market. I would like to have it as a regular use set.

Does yours have a thing on the scamatic called an afc diode?
once i get one of these mine is going to be an everyday watcher.

[radiotron]

if its the same kind of diode does it matter if it came out of a color tv?
to replace the old one

[bandersen]

If their both arranged the same way (i.e. common cathode) it's probably OK. You could also try using a couple common silicon diodes like the 1N4007 connected together.

[dieseljeep]

Originally Posted by bandersen

If their both arranged the same way (i.e. common cathode) it's probably OK. You could also try using a couple common silicon diodes like the 1N4007 connected together.

I always wanted to do that, but never tried. The last time I replaced one, replacements were readily available and never gave it much thought.

[wa2ise]

Originally Posted by bandersen

You could also try using a couple common silicon diodes like the 1N4007 connected together.

1N4007 and similar rectifier diodes are likely too slow to turn on and turn off for horizontal work. But some diodes pulled from old computer switching supplies may work. The ones (Shotkey) that rectify the secondary of the high frequency switching transformer. Another possibility would be signal diodes, the kind used for detectors in radios. Or if you have some 6AL5s laying around, you could use those diodes. That's what they used to use back in the early days of TV.

[Eric H]

I have used common 1 amp 600v silicone diodes to replace these, maybe not ideal but it works.

[bandersen]

So have I with good results. I used some small signal switching 1N4148s in a bugeye set recently too. Those can't handle very much voltage though so might not be a good idea.

[Adam]

I've been using 2 1N4007s for these, it does work. But I just ordered some of those ECG113s, it'll be interesting to try them and see if there's any difference.

[Tubejunke]

Originally Posted by radiotron

Does yours have a thing on the scamatic called an afc diode?
once i get one of these mine is going to be an everyday watcher.

I will have to find my schematic and see on that question. I will throw this out there. I found that there is a video detector diode in mine which seemed to be a problem and the coil that I belive was in series with it is open. Problem for me was that the video section was not what I was battling. No, or very little vertical height and a volume adustable hum for sound is all this set had before and after a recap. I just never figured it all out with little time and no test crt or a scope for proper troubleshooting. Without a test crt there is no way to check test points with a scope. Some test points are on the surface I think on those connection points/strips.