Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12) x

Thread Closed
Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Philco Model 20 rebuild - thanks for all the info
#1

I appreciate this forum. In searching through all the past posts about audio quality on the model 20 I found several good bits of information. The first I did not have to worry about. The spider had been replaced at some point in the past and the speaker re-coned. Both were a pleasant surprise to me. The next useful part was about the detector circuit. I was getting distortion in the audio and read about the modulation levels of early radios so I dropped my transmitter to 25% modulation and cleared that up. Then the reminder about line voltages back in the 30's so I dropped my bench variac to 115 volts.

End result is a very acceptable sound quality. Not as good as some of my other radios but acceptable. I have been wanting to add a model 20 to my collection but so far just had a spare chassis that was too rusty. The spare came in handy by supplying the dial, an rf transformer and the speaker pig tail. It was very nice to have the parts on hand!

Thanks!

Rick


Messages In This Thread
Philco Model 20 rebuild - thanks for all the info - by black85vette - 12-16-2017, 08:07 PM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Philco Model 38-7: what caps & resistors do fail typically?
Since you stated earlier, you have a console 38-7XX.  They also had a 38-7T (table), and 38-7CS (chairside).  A very nic...GarySP — 01:18 PM
Part numbers to model cross
That I wouldn't know, but sometimes the radio document itself shows one, same as the capacitor cans' etc pinouts.morzh — 12:46 PM
Part numbers to model cross
Thank you morzh, that is exactly what I was looking for. Now , is there some where that shows pinouts for Philco power ...Jim Dutridge — 11:37 AM
Restoration of the Canadian General Electric A-87
Thanks for your help Michael. In fact, this video is only an intermediate result. Later I had to apply another tinting l...RadioSvit — 09:01 AM
Restoration of the Canadian General Electric A-87
Great job on the cabinet. PS. In the US notation, "kenotron" refers to specific type of tubes; we call re...morzh — 08:24 AM
Part numbers to model cross
This document has at least some tables of models and parts used. Example: Choke 32-7572, used in 604 radio. Search f...morzh — 08:19 AM
Restoration of the Canadian General Electric A-87
I also checked all the radio tubes on my Hickok 530 tube tester. The 5Z3 kenotron turned out to be faulty, all the other...RadioSvit — 08:02 AM
Restoration of the Canadian General Electric A-87
Well... While the varnish is drying up, I started repairing the chassis... Of course I started by replacing the pa...RadioSvit — 07:12 AM
Philco Model 38-7: what caps & resistors do fail typically?
Hello Martin, Welcome aboard our little community what great Model 38-7 Sincerely Richardradiorich — 12:30 AM
Philco Model 38-7: what caps & resistors do fail typically?
Welcome to the Phorum Martin. I count about 9 paper caps, the 3 electrolytic caps and 2-Y2 safety caps to replace th...RodB — 09:44 PM

[-]
Who's Online
There are currently 1218 online users. [Complete List]
» 1 Member(s) | 1217 Guest(s)
Avatar

>