[RFI] RFI QUESTION

[David Eckhardt]

 I'm out of ideas on this one!  Where does the raspy modulation come from
on the harmonics which changes with position in my radio room on a battery
operated receiver?

Situation:

transmit on 7.010 MHz
receive on second harmonic, 14.020

transmitter:  IC-7300
receiver:  IC-7610
and reversed
Demod:  CW or SSB (or AM, for that matter)

Fundamental sounds clean.  Second harmonic sounds modulated by 120-Hz (and
a few harmonics of the line) and quite raspy - pretty awful.

Receiver:  portable battery operated receiver (Grundig G3) with same
transmitters:  I can walk around the room tuned to the second harmonic and
find places in the room where things are clean and other positions where
the second harmonic (and third) sound awful with 120 Hz raspy
'modulation'.  Any idea how I can account for this localized behavior?  I'm
out of theories.

Dave - WØLEV