🚀 go-pugleaf

Put aside the 60 Hz filter idea for the moment.  Rather than
poor power supply filtering, it sounds like your hum problem
may be due to:

  1.  a ground loop or

  2.  an open shield in  the  patch  cables  connecting  the
      recorder to the receiver.

I assume the receiver is powered by 120 VAC,  although  your
article didn't specify.

If it is indeed a ground loop problem, it could be solved by
breaking  the  ground  connection  at  one end of each patch
cable.

Since I have  to  do  this  when  connecting  my  monophonic
Panasonic recorder to some scanner radios, but not others, I
constructed 2 different patch cables.  One cable has  shield
connections  at  both  ends, and the other cable is a shield
connection at only one end.

If, instead, the problem is an open shield, then  repair  or
replace the cable(s).


In article <2313@rayssdb.ray.com>, iws@rayssdb.ray.com (Ihor W. Slabicky) writes:

>I use a portable stereo cassette recorder to record music off my
>receiver.  When the recorder is powered from the AC line, I can hear
>lots of 60 Hz being recorded on the tape.  Moving the recorder, cables,
>or power cord around tends to lessen the hum.  When I record using the
>batteries, no hum.  Also, when I playback, if I put the INPUT switch
>on the recorder to the MIC position, no or very little 60 Hz hum is
>heard, but when the INPUT switch is set to LINE, lots of hum.  Ideas?

-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Bob Parnass AJ9S,  AT&T Bell Laboratories  -  att!ihuxz!parnass - (312)979-5414