[Guest]

Hi:

In the Riders index Vol 7 page 57 for the Philco 37-630 ...I think there is a problem the way they illustrated the polarity of both capcitors numbers 62 and 60 (12 mfd and 8 mfd) Should the polarity be the other way around. They have the negative side of both caps going up to the field coil??
I also installed a fuse to this set would a 2 amp slow blow be too much?

Thanks
John

[Chuck Schwark]

Looking at the original Service Bulletin No. 251, Philco did, indeed, draw the cap symbols for part no. 60 and 62 upside down in the schematic.
Rider's just re-printed what they were given from Philco obviously.

Thanks for catching those typos!! Will note this on my archive bulletin for future photocopy orders to clients.

The set nominally draws 65 watts at 115 volt AC mains voltage (rating taken from Svc. Bull.) which is 565 milliamp, or 0.56 amps on the AC primary.

If you are running the set on today's 120 volt AC mains, then the amperage draw is 0.54 amps.

I would use a 1 amp Slo-Blo fuse instead.

If the set draws significantly more than a 1/2 to 3/4 amp, then I'd look for excessive leakage in filter caps especially and other wax-paper bypass caps or incorrect audio tube biasing voltage, causing excessive plate current.