Schematics needed
 

Hi everyone,

Over the next few weeks I plan on replacing the paper and electrolytic capacitors on all my 'user' radios, but need to order the proper values. Does anyone have the schematics for the following?

1) Zenith G/C730 (chassis # C705)

2) Zenith K731 (chassis # 7M07)

3) Zenith H845 (chassis # 8H20)

I realize I can order these from justradios.com, but if anyone has them handy, that would be great. Are schematics usually sent in a pdf format?

Finally, any collective wisdom for recapping the H845? I've read these need less updating than other, older sets. Suggestions? Where's a good place to put an in-line surge fuse?

I may be able to scan you the sams tomorrow. It will be a jpg file hosted on our site so you can download it, then I'll remove them once youve got them to conserve our disk space.
I always put the fuse right first where the power enters the set in the hot lead. That way if anything shorts. filaments, diode, whatever, it blows.
1/2 amp would probably do for a table top radio.

If a set is using ceramic capacitors they are usually still good. You may be able to upgrade your audio quality by replacing any ceramics in the audio circuit with mylar. I'd go ahead and just do those electrolytics while you have the chassis on the bench, even if the old one looks good, just so you don't have hum problems creep up in the next 5-10 yrs.

Hi Chad,

>I may be able to scan you the sams tomorrow. It will be a jpg file hosted on our site so you can download it, then I'll remove them once youve got them to conserve our disk space.

That'll be great. I'll try to download and save right away.

> I always put the fuse right first where the power enters the set in the hot lead. That way if anything shorts. filaments, diode, whatever, it blows.
1/2 amp would probably do for a table top radio.

I think this is an important upgrade, because plugging and unplugging a set seems a major hassle. That's the main concern, correct?

> If a set is using ceramic capacitors they are usually still good. You may be able to upgrade your audio quality by replacing any ceramics in the audio circuit with mylar. I'd go ahead and just do those electrolytics while you have the chassis on the bench, even if the old one looks good, just so you don't have hum problems creep up in the next 5-10 yrs.

I'm almost positive the H845 uses ceramics. I wonder how many are in the audio circuit? Perhaps just one?

If you can't get to it right away Chad, don't worry about it. Feel free to send me a PM or a email after you upload.

Thanks again Chad, as always!

Nolan, I couldn't find the sams index last night and was time to go home. I know I can find you those sams but I need to find that index. If you can find out what folders those radios are in it will help.

H845: 725-10
K731: 778-10
C730: 478-19 - I might have this one... none of the others though...

Nope - don't have 478...

Tom thanks for finding those numbers, I should be able to find those sams this weekend.

Nolan I haven't forgotten about those sams but have had a lot of juke work at the shop so haven't gotten to them yet but I should in this week sometime.

If you do scan the Sams for the G730, I'd appreciate a copy - I picked one up this last weekend at the AWA flea market. It will join my C730, T825, 8H061, L600, R615 and maybe a few others that have slipped my memory...

No problem Chad. I just returned from a 10-day business trip, so I haven't had any time either. Thanks for the shout-out!

O.K. the sams are ready:

http://www.retroaudiolab.com/sams

Got it - thanks!

Me too...thanks Chad and Tom. Much appreciated!