[Steve Davis]

The next step is to see if you can get an IF signal through. You will need a signal generator, do you know someone that has one?

Steve

[mikeyhitchfan]

No, I don't know anyone. I thought about getting a used one on eBay. Perhaps it would be a good investment if I'm going to do this as a hobby. Any suggestions on what models might be reasonable? Heathkit?

Until then, there's no other tests that I can try?

[morzh]

Does it have a loop antenna? If yes, is it connected to both terminals (a 5pF cap and RF chassis which is also the tuning cap's rotor?)
The loop in essence is that 4th coil you need to check.

[mikeyhitchfan]

Yes, the antenna is attached..one side to antenna side lug of tuning condenser, the other side to a lug terminal attached to the top of the tuner (which doesn't appear to have a cap), which then jumpers a connection to a tune pin below. I checked continuity and soldering points. My other Philco's have one side attached to chassis ground. I tried touching the wire there and to the osc side lug, but it didn't change anything.

[morzh]

Have you checked or repaced that 5mmF cap it is attached to? Or is it a mica?

[mikeyhitchfan]

    Here is a picture of the antenna attachment points. It could be a mica cap on top.

[morzh]

Which one is the cap, on the left (a piece of a phenolic board) or the right (looks like a trimmer cap)?


OK, never mind, the loop is Not connected via the cap, it is in parallel to the tuning cap.

[mikeyhitchfan]

I guess both sides have trimmer caps under the screws, but that center piece just looks like a lug to attach a wire to. I'm a newbie and a bit confused comparing this to the schematic. The radio was worked on in the past as it had some new caps below, so I'm not sure something wasn't altered that is making it not work correctly.

[morzh]

Do you get the hum when touching pin 6 of 14A7?

[mikeyhitchfan]

Nope, no hum there. I get hum touching the center post of volume control.

[morzh]

Does the volume pot show finite resistance end to end? (not from center to end but end to end)? What is it?


Also: what is the DC voltage on any end of antenna loop relative to the chassis? shoud be 0 to negative.

[mikeyhitchfan]

0.439 mohms from l to r pin

[morzh]

OK good.
Now the DC voltage loop to chassis.

Also, when you checked 14B6, did yor tester check both diodes and triode or tripde only?
Does the tester check mutual conductance or emission only?

[mikeyhitchfan]

4.40 volts at each ant connection point

[morzh]

Plus or minus?
Should be below zero.