[Elecraft] K3: Loss of rx signal

[AI1V]

When running some CW contacts on 40m, I had the unpleasant experience of
having the rx go almost totally dead (very low noise level - no signals)
immediately after calling a station.  Nothing seemed to recover it so I
power cycled the radio in time to hear the other station send ..--..  This
happened a couple more times.  I hadn't notice this happening before.  The
only new thing I had recently tried was the ALT1/ALT2 filter settings
(pretty cool feature).  While it is somewhat unpredictable, the phenomenon
appears to be strongly correlated with the use of this feature.  I have also
found that I can recover from the "dead rx" condition by tweaking the shift
or sometimes the width, but sometimes that doesn't work and I need to power
cycle.  Since then I've stopped using ALT1/ALT2 and haven't had it recur. 
Note: this problem appears in the new firmware as well as the last revision.

On a possibly related note - I was running the hi and low power tx gain cal
procedure after updating the firmware.  By mistake I spun the width knob
instead of the pwr knob to adjust the power.  At some point the filter setup
got quite hosed - the width display showed around 4 khz, but the passband
display was at minimum width.  The next time I tried keying (holding tune) I
got the nefarious ERR TXF message!  I also noticed that the noise level on
the rx was way down (I was connected to a dummy load) from where it was
earlier.  Power cycling the radio brought everything back to normal and I
completed the cal.

It appears that something is whacking filter parameters in the DSP - or at
least that's what it's acting like.  I've reported this to support at
elecraft.

Nevertheless, the radio kicks butt.  The mojo is alive and well - worked 18
states this weekend including the west coast on 40CW loading my rain gutter
through an SGC tuner!

Rick
AI1V
K3 728
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