Will a 40 mfd electrolytic where an 8 mfd should be cause speaker hum?

Hi Mike: Helps to know the make, model and the cap in question. Too large a cap can be a bad thing but normally won't cause hum.

Richard

:Hi Mike: Helps to know the make, model and the cap in question. Too large a cap can be a bad thing but normally won't cause hum.
:
:Richard

Thanks, Richard - It's a Philco Model 70. The radio works, but has an aggressive hum and a loud station will fade away and then suddenly return with a pop, only to fade away again in a kind of cycle. I noticed that one of two 8 mfd caps was replaced with a 40.The other with a 10. If you have any other thoughts about what might cause the hum and fade, I'd appreciate them.

Wow! That's was my first old radio.

Concerning the hum, the negative end of the caps may have been connected to the chassis rather than at the resistor tap. Check the cap wiring.

The fading and popping back on again could be a number of things. Most likely other caps are bad. Some are in bakelite blocks and some in metal cans. Highly recommend you go to Chuck's web site philcorepairbench.com for more info on Philco caps and other helpful tips.

Richard

:Wow! That's was my first old radio.
:
:Concerning the hum, the negative end of the caps may have been connected to the chassis rather than at the resistor tap. Check the cap wiring.
:
:The fading and popping back on again could be a number of things. Most likely other caps are bad. Some are in bakelite blocks and some in metal cans. Highly recommend you go to Chuck's web site
philcorepairbench.com for more info on Philco caps and other helpful tips.
:
:Richard

Thanks, Richard. I'll check it out.

Mike it sounds like you should replace the current caps with new 10MF and go from there. If you didn't do the previous replacement I highly recommend it.

::Wow! That's was my first old radio.
::
::Concerning the hum, the negative end of the caps may have been connected to the chassis rather than at the resistor tap. Check the cap wiring.
::
::The fading and popping back on again could be a number of things. Most likely other caps are bad. Some are in bakelite blocks and some in metal cans. Highly recommend you go to Chuck's web site
:philcorepairbench.com for more info on Philco caps and other helpful tips.
::
::Richard
:
:Thanks, Richard. I'll check it out.