[Elecraft] K3 Attenuator Turning Itself On

[Dennis]

I have a situation where a K3 with the attenuator off, when bandswitched 
to 160M, turns the
attenuator on.  I know this is the correct behavior for the K3 if the Rx 
signal level is in the range
of +13 to +20dBm.  That signal level, by the way, is on the order of 
S9+90dB!  And, yes, you
would be correct, the receiver is severely blocked and the S-Meter reads 
a solid S9 and the
band is mostly intermod.  A scan of the MW band shows a dozen stations 
that are S9+20,
with the strongest stations being S9+45.  I haven't ruled out a very 
strong signal that may be
there, but it wasn't in the MW and I have yet to find it..  One of the 
first things I intend to do
when I get back to the station is to use a spectrum analyzer (with a 
step attenuator in line) to
see if that very strong signal exists.

If I don't find a very strong signal, what conditions, in your 
experience, would create a signal
strong enough to turn on the K3 attenuator?  Or are there other 
circumstances that would cause
the K3 attenuator to turn itself on?

As additional info, if the preamp is on and the radio is switched to 
80M, the preamp will turn
itself off.  This indicates an RF signal of +3 to +10dBm- or S9+80 or 
so- when the radio
is switched to 80M.  In both cases, there are no known transmitters 
operating within 500 yards
of the antennas in any direction.

Please send replies to me and I'll summarize.

Dennis W1UE