Zenith 10S464 and 7S633

[TUD1]

I got two Zenith sets at an estate sale today for $20 each. I kind of wish I'd left the 7S633, because not only is it really beat up, but Zenith really cheaped out by 1942. I'd at least like to get my money back as I have no interest in repairing it. The 10S464 however, is in much better condition. I'm taking it to the radio club tomorrow in hopes of getting it to at least make more than a 60Hz hum. It's missing the station preset assembly. Could this keep it from playing? When I was moving the radio out of the sale, it was extremely crowded, dark, and loud. The preset assembly fell out of the radio and just then, somebody asked me if I needed help. I instantly forgot about the assembly until I got home.

[Electronic M]

I've got one like the pictured set, for $20 at a radio meet. The cabinet was mint, and the 25Hz power version of the chassis in it was still working nicely on original caps.

[TUD1]

I got some things done on the 10S464. I got the preset back the day after the sale, and after that, I put new lytics in it. It's drawing a lot of current, and none of the tubes are getting hot. The rectifiers are getting extremely hot. Is something keeping B+ from getting past the rectifier circuit? I plugged the speaker into a different chassis and the 10S464 speaker is good.

[jr_tech]

Bad or backwards electrolytics, perhaps.

jr

[Electronic M]

The tuning eye wiring may be shorting the B+ to ground. I had a Zenith console chassis where the B+ wire direct from the rectifier to the tuning eye was rubber and where that wire passed through a chassis hole the rubber had cracked off and the B+ lead was shorting to chassis....
Is the rectifier tube original and good?

[TUD1]

It has two NOS National Union 6X5GT's in place.

[maxhifi]

is it possible it has 6x5 disease? (h-k short) try operating it with one pulled, then the other. It's unlikely they are both shorted.

[TUD1]

Like I said, I tested the speaker with an 11S474 chassis. I used the same recitifier tubes in both chassis.

[zeno]

You didnt over pay thats for sure. These radios can
give almost FM audio. Almost nothing post war will sound near as good.

73 Zeno

[TUD1]

I plugged the 10S464 in to do a quick test. It had a Tung-Sol 6X5GT and a Philco 6X5GT. It's a good thing I had my hand right on the power knob when I did - otherwise, the transformer would have toasted. I heard a big crackle, turned off the radio, and shortly after, smelled the most horrendous smell. I put in two known good 6X5GT's and the transformer is still good. Don't let anyone tell you 6X5GT's are safe. 6X5GT's are NOT SAFE!

[Titan1a]

My Zenith 7S363 knows! Solid state rectifier replacement. Known good thing.

[TUD1]

I was going to work on this radio today, but I didn't feel like dragging it all the way down there and all the back and get a(nother) schematic and all that crap. The rectifiers are still getting extremely hot, the 6V6's are still lukewarm, and all the rest of the tubes are stone cold. The electrolytics are installed correctly. It also makes a weird echo if you move the chassis around in the cabinet.

[jr_tech]

Have you measured the B+ voltage at the cathode(s) of the rectifiers, on either side of the speaker field coil, at the plates of the 6V6s, to find out where you are loosing B+ ?
When you say "stone cold" what exactly do you mean? are the tubes lit up or not?

jr