03-07-2011, 09:45 AM
Ok, I got one more question because I can't stop thinking about this radio...
Would there be any other symptoms of bad electrolytics other than a buzzing? Everything I read about buzzing all ended up with bad elec caps. Should I replace those again? I wish I had a cap tester... is there any useful way to test a cap without a cap tester?
Hi Brandon,
To answer your questions Yes there are some other problems that will cause a buzzing or hum in your Philco. I think the easiest way to unscramble your problem is to go though it stage by stage try to find where it is coming from. First off make sure that the two 20uf filter caps are connected with the proper polarity. You will notice a + sign at one end and or a - at the other. It is very important the + end of the cap is connected to the field coil and the - goes back to the pushbutton off/on switch.
Next take a wire and connect it to pin 5 of the 50L6. Take the other end and connect it to the - side of the filter cap. If filter caps are bad you will still hear hum if not it's coming from elsewhere. One other possibility is a bad 50L6. A short internally between the control grid and cathode will cause hum also.
Report back with findings
and good luck!
Terry
Would there be any other symptoms of bad electrolytics other than a buzzing? Everything I read about buzzing all ended up with bad elec caps. Should I replace those again? I wish I had a cap tester... is there any useful way to test a cap without a cap tester?
Hi Brandon,
To answer your questions Yes there are some other problems that will cause a buzzing or hum in your Philco. I think the easiest way to unscramble your problem is to go though it stage by stage try to find where it is coming from. First off make sure that the two 20uf filter caps are connected with the proper polarity. You will notice a + sign at one end and or a - at the other. It is very important the + end of the cap is connected to the field coil and the - goes back to the pushbutton off/on switch.
Next take a wire and connect it to pin 5 of the 50L6. Take the other end and connect it to the - side of the filter cap. If filter caps are bad you will still hear hum if not it's coming from elsewhere. One other possibility is a bad 50L6. A short internally between the control grid and cathode will cause hum also.
Report back with findings
and good luck!
Terry
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
