10-13-2007, 10:43 AM
Hi Tony, and welcome!
If your 531 has a Utah speaker, then it is a replacement. The original Philco/Timmons speaker was of the magnetic type, high impedance, and has a pot metal driver which goes bad over time. A replacement speaker with matching audio output transformer will give the radio better fidelity (i.e. will sound much better), at the sacrifice of originality. But if the original speaker was bad anyway, you don't have much choice if you want your set to play...
Be careful once you reinstall the set in the cabinet. There are some bakelite washers that mount in the phonograph jack to insulate it from the brass escutcheon which it mounts on. Lose one of these, and you may lose all sound from your unit due to the jack shorting out from the missing bakelite washer(s). (This may not apply to your set since it has a wooden cabinet, but it is very much applicable to the metal cabinet 511 series sets.)
Please follow Stude's advice and replace ALL of the paper capacitors. Your set did not originally use electrolytics in the power supply circuit; instead, it uses a large, rectangular can which houses six capacitors. It's up to you if you want to replace the old filter caps with mylar or electrolytic. You can purchase 1, 2 and 4 uF mylar caps but they will be physically large (yet nowhere near as large as the originals). If you want a really compact component layout inside the filter can, use electrolytics - the 1, 2.2 and 4.7 uF electrolytics are quite small. You must watch polarity though if you use electrolytics.
You can remove the old filter can from the radio, disassemble, melt out the old components and mount the new caps on the terminal board so that they will be inside the can when reassembled and reinstalled in the radio.
A schematic may be found at http://www.philcoradio.com/tech/images/511.jpg .
If your 531 has a Utah speaker, then it is a replacement. The original Philco/Timmons speaker was of the magnetic type, high impedance, and has a pot metal driver which goes bad over time. A replacement speaker with matching audio output transformer will give the radio better fidelity (i.e. will sound much better), at the sacrifice of originality. But if the original speaker was bad anyway, you don't have much choice if you want your set to play...
Be careful once you reinstall the set in the cabinet. There are some bakelite washers that mount in the phonograph jack to insulate it from the brass escutcheon which it mounts on. Lose one of these, and you may lose all sound from your unit due to the jack shorting out from the missing bakelite washer(s). (This may not apply to your set since it has a wooden cabinet, but it is very much applicable to the metal cabinet 511 series sets.)
Please follow Stude's advice and replace ALL of the paper capacitors. Your set did not originally use electrolytics in the power supply circuit; instead, it uses a large, rectangular can which houses six capacitors. It's up to you if you want to replace the old filter caps with mylar or electrolytic. You can purchase 1, 2 and 4 uF mylar caps but they will be physically large (yet nowhere near as large as the originals). If you want a really compact component layout inside the filter can, use electrolytics - the 1, 2.2 and 4.7 uF electrolytics are quite small. You must watch polarity though if you use electrolytics.
You can remove the old filter can from the radio, disassemble, melt out the old components and mount the new caps on the terminal board so that they will be inside the can when reassembled and reinstalled in the radio.
A schematic may be found at http://www.philcoradio.com/tech/images/511.jpg .
--
Ron Ramirez
Ferdinand IN
