Philco 40-180 Compensator Alignment
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>Around 1232 tube, measured 182V (160V schematic) and 179V (105V schematic).
Ok Those are a bit high. The 182v tell us that #13 is working. If it wasn't you would have 0 volts there. Having both the plate & screen grid voltages high means that the tube isn't drawing much of any current. So need to look at #7 the 390 ohm resistor. Also check the ground connection. They can get oxidized a not make a complete connection. The pins on the loctal tubes oxidized and can make poor connection. Or could be a weak tube.
So folks don't care to work on the '39-'42 Philco as that use rubber coated wire (US sets) and Loctal tubes.
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
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Did alignment on Philco 1 model 40-180 (good voltages), and picks up additional stations now and volume is ideal.
Tried alignment on Philco 2 model 40-180 (high voltage and suspect Part 13 RF coupling) and couldn’t find the signal through the RF alignment process.
Am I out of luck, or how does one go about finding the required part?
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Thanks Terry. Got your note just after I sent mine. Will try your suggestions. Appreciate your help immensely.
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The 390ohm resistor tested at 415ohms, so ok. Ground looks to be good. Cleaned 1232 tube socket and pins but only made nominal difference to voltages. Tried a different 1232 tube and had no impact.
Tried doing alignment again as is, but can’t find signal anywhere on dial, whether setting signal generator at 580 or 1400. I do get some but not all stations in the area, but max volume at about 60%.
Will replace all tubes with tubes from other Philco 40-180 that I successfully aligned to see what happens.
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Something else came to mind. Is the heater in the 1232 glowing? On loctal tubes it can be difficult to see do to the getter flash (that's what makes the tube look like chrome on the inside). Dark room and looking from the bottom up helps to see it. If not this would indicate a bad connection in the 6.3vac heater line at the socket or between the socket and the tube's pin.
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
Posts: 12
Threads: 1
Joined: Aug 2022
City: Calgary
State, Province, Country: Alberta
Yes, the 1232 tube is glowing. I also replaced all tubes with tubes from the other Philco 40-180 (which is now working wonderfully), with no resultant impact on performance on this 40-180.
Assuming this still could just be an alignment issue, any idea why I can’t seem to pick up any signal from the signal generator? It didnt matter if at 580kc or 1400kc and I tried to find it, or tried either moving signal generator dial or radio dial, I couldn’t get any signal tone through the radio. Is it possible that the radio is so badly aligned that no signal tone shows up across the entire Broadcast band and I have to move the compensators 19 and 19A a SIGINIFICANT amount to find signal? I do get a couple stations showing up where they should be at 1060 and 1100, and much much weaker station signals showing up at 660 and 700.
This all is further complicated by the fact that the original alignment instructions have compensators 19 and 19A reversed from what they should be.
I’m new at this, but I am used to only having to move compensators nominally before I find maximum volume.
Thanks in advance for any help offered.
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I should have mentioned that I was able to align for 455kc IF and 18mc SW. It was the RF alignment that I’m having issues finding the signal for.
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Hi Gdolf,
I've been casually following the thread and it seems like you are slightly confused about the alignment. When you tuned the IF to 455 KHz the IF is aligned for both the SW and Broadcast bands. Now you can send rf signals to the radio and make adjustments to align the dial to the correct signal frequency and maximize the signal reception.
If what you indicated about the SW band is true, your radio is working fine except no Broadcast Band signals are getting through. Both bands are using the same circuits from the 1232 to the speaker so the problem would be with the Range/Band switch or the associated coils/transformers. To change bands the switch disconnects one set of coils and connects a different set. I would concentrate on the switch contacts and wiring. It may be a PITB to do but these are 80 year old contacts and need a thorough cleaning with a strip of paper and contact cleaner; be gentle. Also, be sure all the coils have continuity and have solid solder connection.
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I will clean as u suggested, but I do get some local stations when I switch to Broadcast, it’s just that many of the AM stations can not be found and those that do come in are at lower volume. I had this issue with another Philco 40-180 and it turned out to be an alignment issue. However, on this particular 40-180, I can’t even find the signal from the signal generator so, as a result, can’t really perform the alignment.
I’ve been hesitant to turn the compensators too, too much, during the alignment process as I’ve heard horror stories of “rookies” trying to align a radio, only to so badly misalign it they can get any stations back. I will maybe be a bit more aggressive in my search for the 580 and 1400 signal.
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My alignment problems were due to the mislabeling of compensators 19 and 19A.
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Ahh, the old slight-of-hand trick. Frustrating. Now maybe both radios can be tuned up nicely.
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Hi gdolph, in post #21 you state that you can receive stations at 1060, 1100, 660 and 700 at the correct spot on the dial. If you can’t pickup the 580 and 1400kc from your signal generator perhaps there’s a problem with your test setup or the generator itself. If those stations you mentioned are coming at the correct spot on the dial I wouldn’t mess with the oscillator alignment but instead concentrate on the RF alignment and associated circuitry including coils and switch contacts as already mentioned. GL
Ron
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