[Elecraft] Intermittent loss of receiver sensitivity

[jhaynes@alumni.uark.edu]

On my K2 s/n 2838 lately I've noticed the receiver sensitivity going
down the drain from time to time.  I haven't had time to explore all
the variations, but  it definitely happens on 10 and 14 MHz.  When it
happens, a power cycle or just changing to a different band and back
will bring the sensitivity back.  Also when it happens the preamp
and attenuator are off.  If I switch on the attenuator the receiver
sensitivity increases, and if I switch on the preamp it increases
even more.  So when the fault is happening the sensitivity is lower
without the attenuator than with it.  The S meter indication does not
change when the fault is present.

Has anybody else seen something like this?