The PHILCO Phorum
Philco 39-7 issues - Printable Version

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Philco 39-7 issues - Jeff Lepore - 02-19-2026

Hello everyone, I’ve been working on a philco push button model 39-7. I’ve replaced all caps, checked resistors, and replaced all tubes. This set had been worked on before I got it. I get absolutely no sound. After replacing all parts mentioned above I got a motor boating sound for about 5 minutes, then that quit. All tubes light up except pilot light. I know the right push button controls dial tuning, but a I have no wires going to that button. I can’t figure out the schematic. I’ve seen videos on this radio and have seen two wire going to that push button. And as you can see from pics someone had done some soldering. Any idas would be greatly appreciated. Thanks 
Jeff Lepore[attachment=34168][attachment=34169][attachment=34170]

RE: Philco 39-7 issues - morzh - 02-19-2026

Gosh, this thing is dirty and the rubber insulation is all cracked.
And what is that rope? Doesn't look like the dial cord.

https://www.nostalgiaair.org/pdfs/Philco-Radio-and-Television-Corp/Philco-Radio-and-Television-Corp-39-7.pdf

This sch?

There should be wires shown by the dash lines, one goes to the antenna xfmr, the otehr to the oscillator coil #6 or the cap 6A (in parallel to the coil).

RE: Philco 39-7 issues - MrFixr55 - 02-19-2026

The schematic is a little funky. In your set, the solid drawn C3A and B does not exist, the dotted line one does. The push buttons determine whether a push button capacitor channel is in use or if the tubing cap is in use. One of those push buttons will connect the tuning cap. Clean the switch, and ensure that the tuning cap is connected to the switchgear, that the switchgear is connected to the tuning cap and with the correct button pushed, the RF stator is connected to the grid cap of the 6A7 and to the antenna coil secondary, while the oscillator section stator is connected to the Oscillator coil.

Hope this helps.

RE: Philco 39-7 issues - Jeff Lepore - 02-19-2026

Thanks for the suggestions, but everything I've tried, nothing works. I can't even get static. Something is dead. Might be for the dumpster.

RE: Philco 39-7 issues - Joe Rossi - 02-19-2026

Jeff,  After replacing the caps, resistors, and tubes you’re going to give up? I’d replace the crumbling wire next (could be a short or an open circuit), carefully clean the grid cap connections to insure proper contact, and figure out the twine that Morzh pointed out.  Maybe post a couple of photos of the underside would be good. Keep talking to us!   Icon_wink

Joe

RE: Philco 39-7 issues - morzh - 02-19-2026

I restored a 39-6 which is the same radio without pushbuttons. A simple animal.

So.

First things first.

1. Make sure your speaker's good. Disconnect one voice coil lead from the output transformer, make sure the voice coil has continuity.
Then check the Field coil. Right in-circuit, 1700 Ohm. Last, check the transformer's primary. 850 ohm, in-circuit. No problem with some plus-minus, as long as it is not a shor or open, or tens of Kiloohms instead of hunderds of Ohms etc.

OK, OK, I know, you had motorboating before, but Gosh knows, you coulda killed it. Due diligence.

2. Clean the darn thing. You don't know if the dirt is playing tricks on you. Tube sockets, especisally. Take out the tuning cap, at least blow it with some compressed air. All cracked wires - replace.

3. Check the tubes, not just for emission. yea, I know you replaced them. But still...
4. Every single resistor, see if you forgot any.
5. All magnetics: continuity. Every coil of every RF transformer.
6. Check the voltages.
7. Touch the 1st audio grid, see if it hums. Also check your volume pot.

We'll stop at this.
You should have your audio working before anything else.

RE: Philco 39-7 issues - MrFixr55 - 02-20-2026

Hi Jeff, don't give up; it is always darkest before dawn! +1 on what Morzh said.

Divide and conquer!
Touch the grid cap of the Audio tube (75). You should get hum. If no joy, verify the power supply, then attack per Morzh's instructions.

If the audio is good, touch the grid cap of the IF tube. You should get noise. If you ran a wire from the grid cap of this tube to the grid cap of another AC radio, you should get a lot of noise when attempting to tune the other radio, possibly actually stations, not clear, as I did not instruct you to connect the chassis together (This may be dangerous if the RFI caps (Death Caps) are leaking or one set is AC-DC).

If this test passes, then your issue is in the Convertor (1st Detector) stage. You previously stated that you have traced the circuit to the pushbutton switch that is supposed to connect the tuning cap to circuit and the cables appear to be missing. You can temporarily mod the radio to a 39-6, eliminating the pushbuttons. Check your wiring. Someone may have actually tried to do so but did it incorrectly.

Hope this helps.

Keep us all posted; we really want success for you!

RE: Philco 39-7 issues - Jeff Lepore - 02-20-2026

Thanks for all the advice. I tried all that you suggested, but still no sound. I inherIted this radio and realized quickly it had been modified. Like the dial string is some kind of rope. it works but is tacky. And they’re globs of solder at many connections. I strongly think the problem has to do with the push button to control the tuner. Missing wires to push button. I looked at the 39-6 schematIc. It’s the same as mine. I would like to bypass the buttons, but have no clue how to do that. I’ve restored the cabinet, but I would really like this thing to work. I don’t give up, just frustrated. Next step will be to rewire all the cracked wire. That will be fun…. Thanks again. I’ll keep you posted.

RE: Philco 39-7 issues - morzh - 02-20-2026

So when you touch the grid of the 1st audio (cap of 75 tube), no hum?
And if you touch pin 4 pf the 41 tube, also no bum?

Please be specific in what "I tried what you suggested, but still no sound".
Because if this is the case, it should be fairly easy to see why there is no sound.

RE: Philco 39-7 issues - Jeff Lepore - 02-20-2026

I get no hum from 75 or 41. I get 2 ohms on voice coil with set on and off

RE: Philco 39-7 issues - morzh - 02-20-2026

>> I get 2 ohms on voice coil with set on and off

???
Please explain, not sure what "measuring ohms with set on" is.


Now, your output is not working.

When we ask you to test the speaker, did you test it and how?
Do the output tubes have proper voltages on them?

RE: Philco 39-7 issues - MrFixr55 - 02-21-2026

Hi Jeff,

OK, by touching the grid of the 75, you received no hum.  This is bad but is good.  At this porint, you work "backwards" starting at the speaker, power supply, etc.

The next instructions that I give may be very basic.  Please forgive me if your skills are more advanced than my instructions.  In all things, please exercise caution to prevent burns and dangerous electrical shock.  All numbers referred to are from the schematic.  Use either the schematic on the Phorum or the one from Nostalgia Air.  Note that generally, the term "cap" is shorthand for capacitor unless referring to the "grid cap" on the top of some of the tubes.  "Pinouts" for the rectifier and output tube are attached.  The view is from the underside of the chassis.  For the 41 tube, Pins 1 and 6 are larger in diameter than the other pins.

   

   

The following issues will cause no audio.  Ensure that the set is unplugged.  Verify resistance readings to determine:
Perform the following tests very carefully as you are exposed to dangerous or fatal voltages.  Do not proceed if not comfortable or familiar with safely making voltage measurements on live line powered equipment:
I feel rather strongly that your main problem will be found following the above steps.  This will restore function of the audio section and will pass the "hum test" (touching the grid cap of the 75 detector / 1st audio tube with the volume control set high or the grid cap disconnected).

There may be other issues.  Please DO keep us posted; we are very happy to help you to successful completion of this project!!

OK, gang, gotta go and prepare gfor the upcoming blizzard!!

RE: Philco 39-7 issues - Jeff Lepore - 02-21-2026

Before I try these instructions. Quick question: I have Cap #26 connected to ground. Where should it be connected? Previous owner removed the 12 mfd cardboard between the top of chassis and underneath. So old cap was grounded. so that’s where I grounded the new ones. Obviously that was wrong. I have grounded cap 25 to ground and also cap 26.

RE: Philco 39-7 issues - RodB - 02-21-2026

Hi Jeff - I highly recommend that you not power up the radio until cap 26 is rewired. As MrFixr stated cap 26 is not supposed to be grounded. The schematic shows the center tap of the power transformer connected to resistor 24 as the point where the negative of cap 26 should be connected. This is probably a terminal near resistor 24. This terminal should measure about 300 ohms to chassis ground.

RE: Philco 39-7 issues - morzh - 02-21-2026

While I doubt #26 connected to GND would silence the radio all by itself, it is wrong and should be fixed.
Now the question, what the centertap of the Hi-V transformer is connected to?