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Philco Model 630X Repair Issues - Printable Version

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Philco Model 630X Repair Issues - dfields69 - 10-18-2014

Hello again! I have a model 630x (console) just did the recap, reworked the bakelite caps properly. I got to the ELectrolytics and experienced the same level of confusion I've seen others experience concerning the multi-value electrolytic can with that pesky 10 mfd cap. 8-8-10 is the configuration. I have a 10 mfd 450V electrolytic hooked up apparently backwards; the positive is wired to B- with the negative ends of the two 8 mfd. caps and the negative is wired to a ground on the 78 tube socket just above. I replaced a yellow Aerovox 10 mfd 50 v. that was gooped in with ALOT of solder. Do I HAVE to use 50V or will 450V be okay? Also, I do not have anything soldered to the can threaded ring any longer. The schematic has the two 8 mfd. caps wired with neg. to B- and the 10 mfd hooked to B-with a ground to chassis so I saw no need to continue using the can as a source of circuitry for the set. The set hums and will not pick up a station right now. It also has a terminal board mounted on the left side of the chassis that had a cap listed as part #68 which is the id for the pilot lamp??? I found the cap, 30-4134 on Philco repair bench to be a .25 400v. Appears to affect the shadow tuner. Would it also affect the radio receiving stations if it was open? The shadow tuner lights up but the meter does not swing as you tune the set. The tubes are all good no leaks or shorts. The 42 tests just a few clicks into the green good range on my Precision 612 tube checker (calibrated and repaired last summer.) This thing has me pulling my hair out. Is the ground to chassis used for the 10 mfd cap through the 78 tube socket OK to use? I'll go home and putz around with  it some more and wait to hear something. 

RE: Philco Model 630X Repair Issues - Mondial - 10-18-2014

The negative terminals of all three electrolytics should connect together. This point is also connected to the center tap of the power transformer, which is the most negative point in the radio.  The positive terminal of the 10 uF cap should connect to chassis, but the 78 tube socket may not be the best place. The tube socket ground is done through one of its mounting rivets, which tend to get loose over time and develop a high resistance. Better to connect to a terminal that is securely screwed to the chassis, like the ground terminal of bakelite cap 20.

It is ok to use a higher voltage electrolytic for the 10 uF cap.

RE: Philco Model 630X Repair Issues - dfields69 - 10-19-2014

Thanks for your help! I installed a 10 md 160v with negative hooked to the negative of the two 8 mfd caps and the positive hooked to the ground coming off the #20 bakelite cap you mentioned. The two 8 mfds were wired to the same contact on the speaker socket with the old can cap so I hooked both 8 mfd positive leads to this same contact as it was before. The radio still just hums and you can hear the band and tone switch being changed but no stations? I'm at a loss. Any help that could be offered would be very appreciated!

RE: Philco Model 630X Repair Issues - Radioroslyn - 10-19-2014

I would suspect that a 160v cap is way to low in the voltage rating! Put a 450v job in there else you are going to hear a big BANG!!!! As for the no signal issue better grab the signal generator.
Terry