[Elecraft] K2/100 AM (MW) Broadcast Intermods on 80m

[Steve Kavanagh]

I just had my first opportunity to use the K2/100 on a
fairly large antenna for 80m (inverted L with total
wire length around 150 ft., through a low-pass type of
antenna tuner). I noticed a few fairly strong
intermodulation products from AM (medium wave)
broadcast stations on and around 80m.  There are
several 50 kW stations within 10 or 20 km, but none of
them are really close.  For example, I found the
mixing product of 2 times 1310 kHz and 1150 kHz when
tuned to 3770 kHz (meter reads S9 with attenuator and
preamp off) and the mixing product of 2 times 1310 kHz
and 580 kHz at 3200 kHz.  

These signals were not present on a Drake TR-7
connected to the same antenna/tuner.  They also were
virtually unaffected by switching the KPA100 in or out
(either with power setting above or below 10 W or
using the PA ON/OFF menu settings).  They appeared to
be affected by the attenuator/preamp settings in the
same way as "real" 80m signals, which seems to
indicate that they were generated in the T-R switch. 

Has anyone else experienced this (i.e. is it normal ?)
or should I be looking for problems in or near the K2
T-R switching circuitry  ?

73,
Steve VE3SMA


	

	
		
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