[TenTec] Century 21 audio hum

[Jim Brown]

On Wed,5/31/2017 11:32 AM, Stuart Rohre wrote:
> What about insulating both sides of the audio feed to the headphone 
> jack?  That way, you eliminate a chassis ground loop at the headphones 
> connector.

There is no such thing as a "ground loop." The "buzz" that we often 
blame on these mythical "ground loops" is really leakage current from 
the AC power line. There's a complete description of the mechanism in 
this Power Point. Much of the material here formed the basis for N0AX's 
new ARRL book on Grounding and Bonding.

http://k9yc.com/GroundingAndAudio.pdf

73, Jim K9YC