The PHILCO Phorum
Model 40-180 - Printable Version

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Model 40-180 - tludka - 07-31-2021

I have a Model 40-180 that someone previously had worked on.  I have recapped and replaced many of the resistors that were out of tolerance. Replaced much of the rubber wiring. When I turn it on and press any of the presets or the dial button I get distortion in the speaker similar to filter caps being bad. They are good. The schematic lists the output transformer as having a resistance of 450 ohms. Mine is 3.3K ohms disconnected from the circuit. The P/N is 32-8053N. My question is can this be causing the distortion and is there a replacement equivalent?

RE: Model 40-180 - Radioroslyn - 07-31-2021

Hi and welcome,

Typically with bad filter caps you'll hear 60cy hum and diminish volume/distortion do to the caps turning into resistors pulling the hv down. The opt pri should read in the 100's of ohms not the 1000's. I'd say it's bad. It's not uncommon to find an open pri on the '40s Philco sets. Replacement wise your looking for something with a 12K ct plate load to 2 ohm spk or so. Wattage is fairly low as the hv is low too maybe 2 or 3 watts. https://www.radiodaze.com/push-pull-output-transformer-125c-item-hx125c/ It's a little overkill. Cost isn't much more. GL

https://philcoradio.com/library/download/service%20info/yearbooks/1940/split/Part52-Philco%201940%20RMS%20Year%20Book.pdf

RE: Model 40-180 - tludka - 07-31-2021

Thank you. I will check it Radio Daze.

RE: Model 40-180 - tludka - 08-08-2021

I have never replaced an output transformer. I received a Hammond 125E to replace the Philco 328053. My question is how do I ensure hat I am using the correct set of terminals to solder in.

RE: Model 40-180 - Radioroslyn - 08-08-2021

Hmmmm an E kinda gigantic but it'll work.
Spkr connects to lugs 5 and 6. Blue wire goes to pin 2 of one of the 41 tubes and the brown goes the pin 2 of the other 41 tube. Red wire goes to the + side of #58.

GL

RE: Model 40-180 - tludka - 08-09-2021

That is what I do not understand. The old output transformer did not have a separate tap to go directly to the speaker. The speaker has 4 wires that I did not move. I hooked up the new transformer to the where the old one was attached. It lines up exactly where you stated. Currently the speaker is attached with one wire each side of the field coil #62 and the other two wires to ground. I would think it should work without adding two more wires. Am I missing something?

RE: Model 40-180 - Radioroslyn - 08-09-2021

Sorry your correct but 58 goes to the fc too. The pri has to have hv on it to power the 41 tubes. The sec of the opt one side is grounded on the diagram. You could say pin 6 of the opt The other side goes over the the voice coil pin 5 of the opt. Phasing doesn't matter. Whichever way is more is more convenient. The really important part is that nothing on the primary side is grounded!

GL

RE: Model 40-180 - tludka - 08-10-2021

Thank you. FYI someone was in this set before , there were caps disconnected and I have a 33mmf cap attached one looks like coil G #26. The other end is not connected to anything and I question why it is even there. I do get a audio signal to the speaker when I input at #41. I receive no RF, The problem is it is difficult to 7B7 or 7C6 because they are beneath the padder and coils strip. I applied the I.F frequency to the 7J7 Det Osc but no sound was heard. I have removed the case off of both I.F. transformers. Not sure what the capacitors in the I.F. cans should read.

RE: Model 40-180 - Radioroslyn - 08-10-2021

<I receive no RF, The problem is it is difficult to 7B7 or 7C6 because they are beneath the padder and coils strip.
Are you referring to the pushing button assembly?

RE: Model 40-180 - tludka - 08-10-2021

Yes, additional info. I receive a weak warble sound when I turn the volume all the up. When I turn it down it goes away. If I adjust the ON/OFF/Bass control the warble changes in frequency.

RE: Model 40-180 - Radioroslyn - 08-11-2021

It's been a while since I've worked on a '40 model but there should be 2-3 wires connecting the pb assy to the band switch. Unsolder those and unbolt assy maybe a ground strap to disconnect too. Remove it and set it a side for now you have a clear path to get to IF and mixer stages.
Check and see if you have plate and screen grid voltage on the rf,mixer, and IF amp tubes.
For the squeal try reversing wires on pins 5 and 6 on the opt. Typically it doesn't matter but maybe that inherently different about the transformer. Not to worry it may have to do with there is no audio signal too.

RE: Model 40-180 - tludka - 08-14-2021

I had some time today to work on it. My DEt/Osc tube is a 6J8 the Plate Is at 179 on the R.F. tube 1232 Plate read 181. The grid of the 1232 reads -27 and the Grid -.1 Resistors 12,16,15. CAP 14 all check. Coil 13 read 4.5 ohms. With the 6J8 tube a 150 ohm resistor was added in series with the plate of the tube and the 250mmf cap. There is supposed to be a wire wound resistor replacing the 150 ohm Cathode resistor but I only see the 150 ohm carbon resistor. Still no RF. I am stumped, any ideas?

RE: Model 40-180 - Radioroslyn - 08-14-2021

Looks reasonable so far. Apply a 455kc modulated signal to pin 2 of the 7B7. If you can hear that then apply the signal to pin 6 of the 7B7. Should be able to hear there too. Lastly apply signal to pin 3 of the 6J8. Again should be able to hear it there. Turn the generator output down so you can just barely hear it. Now adjust the trimmers at the top of the IF transformers for max signal at spkr.

RE: Model 40-180 - tludka - 08-15-2021

OK, I tried that and I get no IF frequency. So I removed the IF Transformer and disassembled it. The 47K resistor reads 55.2K and the 2 100 pico farads in series reads .16nf instead of .05nf or 50pF. The wire connected to the resistor is hanging on by a thread. The coils ohm out at 27.8 and 5.1 ohms.

RE: Model 40-180 - tludka - 08-15-2021

My error. The two caps listed as 100pf each read ok. One is at 129pf and the other at 119pf. I replaced the resistor and improved the wire connection. I will reinstall and see if this had any effect.