I'm working on a Zenith H664 and recapping the 6H02 chassis . Should I use a safety cap when replacing C4 ,its 0.05uf @200v wax cap . The schematic is in Riders 22-13 if you can't see my scan .

thanks

Yes, it should be a "safety" cap. Justradios.com has a good writeup on how to select them.

Sams Photofact service manuals...
viewtopic.php?p=2840111#p2840111

Greg.

thanks guys , I have read that just radios article , very good .

That radio has a number of capacitors that might be replaced with "safety" caps.

I'm looking at a copy of the Rider schematic from NA. You can read the component designations on this scan. (Note that Sams use different designations.)

Besides 0.05uF C4, which should be a Class Y cap, we see 0.01uF C8, which should be a Class X cap.

But there's more! Connected to the phono jack, 100pF C17, and trimmer C18, can also connect you to the AC line. 100pF Class Y caps are easy to find. For C18, your best bet is to connect a much larger Class Y cap in series between the jack and the trimmer. 0.001uF is probably large enough. 0.01uF would be OK, too.

Even with the "safety" caps, this unit can be a shock hazard. Be sure that any backs, covers, and all knobs are in place.

This is not the unit to use on your swimming dock, or by the bathtub.

Ted

I forgot about C8 and didn't know about C18 thank you . The only expose metal on this radio is the record holding arm ,its a big hunk of Bakelite.

Between the phono jack and trimmer I could use any value between .001uf - .01uf ? I have some .0047uf X1Y2 caps .

Any fixed capacitance in series with the trimmer should be much larger than the maximum trimmer capacitance to avoid reducing the effect of adjusting the trimmer.

Also, a larger capacitance value will reduce how much the tempco of the fixed capacitor matters.

I'm not sure how much adding such a capacitor would actually help decrease the chances of having a shock hazard.

Ted

Thanks Ted , I'll leave that as is and replace the 100p cap when my order comes in . The original 100p cap is rated 500v ,that could have been the safety cap of its day .