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Philco 84 code 121 no sound - Printable Version

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RE: Philco 84 code 121 no sound - Mike L - 10-31-2016

Stupid question, but I assume I am connecting to the cap with it also connected to the tube? And coupled through a capacitor around .001mf 450v? My test lead on the signal generator also has a built in antenna.

RE: Philco 84 code 121 no sound - Radioroslyn - 10-31-2016

On the grid cap there is very little dc voltage so you don't necessarily need a cap for this procedure. If you where connecting it the plate or somewhere there is some HV you would need to use a cap in series to block the dc from getting into your generator's attinuator circuit.

RE: Philco 84 code 121 no sound - Mike L - 11-01-2016

Well, with the signal generator connected as instructed I get a very, very faint whistle around 1100. Hard to tell dial position with the chassis out of the cabinet. I also get the same tone around 800. I have to put my ear next to the speaker to hear. This is with the generator turned all the way up.

RE: Philco 84 code 121 no sound - Radioroslyn - 11-01-2016

That's with the sg set for 460kc?? Should be able to adj #11 &15 for max output. Dial setting shouldn't make any difference.

RE: Philco 84 code 121 no sound - Mike L - 11-02-2016

Yes, that is with the signal generator set at 460 KC. The only sound that was produced was the very faint squeal at those two dial locations, everywhere else was silent. Where am I registering max out put? Volume or do I connect my VTVM somewhere?

RE: Philco 84 code 121 no sound - Radioroslyn - 11-02-2016

>Where am I registering max out put?
From the spkr to ear.
Is your sensitivity control look like the one in pic??? Is it missing the fiber 1/4 nut???

RE: Philco 84 code 121 no sound - Mike L - 11-02-2016

The fiber nut is there. Any adjustment does not produce any change. I have not tried to adjust 11 and 15 yet, only 17 with the fiber nut.

RE: Philco 84 code 121 no sound - Radioroslyn - 11-02-2016

Give me a call.

RE: Philco 84 code 121 no sound - Mike L - 11-03-2016

Its been late when I get home from work. Saturday after work or Sunday would be the best for me.

RE: Philco 84 code 121 no sound - Radioroslyn - 11-03-2016

Whatever is good for you I'm always around.

RE: Philco 84 code 121 no sound - Radioroslyn - 11-09-2016

Also check the two ground connection, one at the cathode of the 2nd 77 tube it's done though a rivet which maybe a problem and the tap on the 2ndary or the IF coil.

RE: Philco 84 code 121 no sound - Mike L - 11-09-2016

>Also check the two ground connection, one at the cathode of the 2nd 77 tube it's done though a rivet which maybe a problem and the tap on the 2ndary or the IF coil.

Thanks for the info earlier today. I'll check these two points as well. While I have the antenna coil out I'm going to rewind the primary. Can't seem to find a local supplier for the wire so it is going to be a few days before I can continue.

RE: Philco 84 code 121 no sound - Radioroslyn - 11-10-2016

(11-09-2016, 11:44 PM)Mike L Wrote:  >Also check the two ground connection, one at the cathode of the 2nd 77 tube it's done though a rivet which maybe a problem and the tap on the 2ndary or the IF coil.

Thanks for the info earlier today. I'll check these two points as well. While I have the antenna coil out I'm going to rewind the primary. Can't seem to find a local supplier for the wire so it is going to be a few days before I can continue.

Hey, I'm in no hurry![Image: http://philcoradio.com/phorum/images/smilies/icon_lol.gif]

RE: Philco 84 code 121 no sound - Mike L - 11-11-2016

I checked the two ground points referenced in your previous reply and both are good. While waiting for my coil wire to arrive, I pulled the oscillator coil to check those windings and it too has corrosion going on in the small section. The small winding reads 2.5 ohms and the larger 3.3 ohms. Not much more for so much more wire. What should the reading be as there is no reference? Anyway should the smaller coil (oscillator?) be rewound, or is it best to let sleeping dogs lie?

RE: Philco 84 code 121 no sound - Radioroslyn - 11-11-2016

(11-11-2016, 03:52 PM)Mike L Wrote:  I checked the two ground points referenced in your previous reply and both are good. While waiting for my coil wire to arrive, I pulled the oscillator coil to check those windings and it too has corrosion going on in the small section. The small winding reads 2.5 ohms and the larger 3.3 ohms. Not much more for so much more wire. What should the reading be as there is no reference? Anyway should the smaller coil (oscillator?) be rewound, or is it best to let sleeping dogs lie?

The  resistance reading seem about right but on the other hand you've already got it out it's not a big deal to rewind the feedback winding.