[TowerTalk] Slow Attenuation of Incoming Signal

[K7LXC at aol.com]

In a message dated 10/19/2006 12:26:30 P.M. Pacific Daylight Time,  
towertalk-request at contesting.com writes:

>  I've been noticing a strange phenomena that I'm hoping  someone can help 
explain.

>  I'll be sitting in front of the  rig tuning the band and listening when
all of a sudden the background noise  level starts to drop and signals
start to drop in strength.  After a  couple of seconds signals are
severely attenuated.  It's as if there  is a variable attenuator in my
coax line and someone turned it from 0dB to  50dB.  A single tap on the
CW key brings it right back to normal once  again.  It'll stay normal
for minutes or even hours before doing it  again.  A single "dit" from
the key always brings it back to  life.  I've never heard it do this on
any band except 40m which leads  me to believe it is my 40m antenna,
but I'm not sure about that.  I  run a common feedline all the way up
the tower to a remote switchbox which  switches between my SteppIR and
my 2 element 40m yagi.  If it's  limited to 40m then it's either in my
rig OR between the switchbox and the  40m yagi.

>  Anyone have an idea?


    Try the antenna plugged directly into your radio  and then see what 
happens. It's probably related to something else in your  signal chain.
 
Cheers,
Steve    K7LXC
TOWER  TECH