[Nickster]

Hello, I have a philco 20 console bought it about a month ago and didn't work(Low Boy I think it’s called same guts as cathedral model 20) After playing around with the capacitors and wiring I finally got it working, sounded great for awhile. The problem I have is when it finally did play the speaker started to smoke and sparks started coming out of the back side, black wrapping around some coil I think, a small hole developed that the sparks came out of. I turned it off immediately . Any ideas on what caused it, are there parts out there to replace the coil or should I just try and find a replacement speaker, if so any ideas on where I can find one?

Thanks
Nick

[klondike98]

Welcome to the Phorum. Order a schematic and service info from http://www.philcorepairbench.com/schematics.htm . Read this: http://www.antiqueradio.org/begin.htm and other threads about electronic restoration of the Model 20 on this Phorum. Not sure what you mean by playing around with the capacitors and wiring, but all the electrolytic and paper capacitors need to be replaced before you even think about plugging it in again. You may have fried some coils already. Check them all. Replace out of tolerance resistors. There are folks on here that have restored this model who can help with specific problems as you go along. Not sure how familiar you are with electricity but there are sufficient current and voltages in these radios to be fatal so read and learn if you need to. Parts and services sources can be seen here: http://www.philcoradio.com/resourceb.htm

[morzh]

I have 20 console. Was the first radio I fixed.

I would look at the Field coil of the speaker. I think sparks came out of it. Disconnect, measure resistance, see if it is in accordance with the schematic's value. Unlike in many other models the field coil here is not used as a filter and is simply placed across the rectifier's output. The resistance should be 3,100 Ohm.
It is possible the wire of the field coil is simply making a bad connection.

[Nickster]

Thank you morzh, how do i go about checking the resistance?

[morzh]

Well.....you get yourself a DMM, digital multimeter, like this one:

http://www.newark.com/jsp/search/product...75021|plid|

Or...whichever else.

Then you disconnect your power, disconnect your speaker (which is easy - it is connectorized), look at the 20's speaker wiring diagram and measure the resistance across the field coil.

[klondike98]

Schematics of the early and late version of the Model 20 can be seen here: http://www.philcoradio.com/tech/schema.htm