[Elecraft] KX3

[David Robertson]

Everyone.

Some time ago I tried using NAP3 with an external USB stereo input sound
module on my battery operated laptop with my battery operated KX3. Nothing
was referenced to any power line source. The software worked fine.  Hooking
up the battery charger to the laptop or running the KX3 off the main power
supply resulted in a buzz from the KX3 speaker and NAP3 not working.
Disconnecting the I/Q cable killed the buzz.  I had the same problem using
my desktop computer. I purchased some 600 Ohm isolation transformers and
connected them between the sound module of the computer to the I/Q output
of the KX3. The problem went away and NAP3 worked perfectly.

I just got my new KXPA100 linear and control cable. When testing the linear
I had been running NAP3 and I noticed that when I powered off the KX3 and
the KPA100 linear then powered the KX3 back up the linear went in to a
firmware loading mode and was unresponsive to any K3 commands.

The problem seem to be having NAP3 running and linked to the KX3 through
the RS232 port. With NAP3 running and it's poling the KX3 from the computer
caused interference between the KX3 issuing commands to the KXPA100 during
power up.  Shutting down NAP3 then powering up the KX3 resulted in
everything starting up fine and full control to the linear from the
KX3. After everything is started you can run NAP3 with no problems, just be
sure the software is off before starting the KX3. I have not used any other
pan adapter software but if it needs input from the KX3 it may cause
problems when left running and trying to start the KX3 with the KXPA100
linear.

The KXP100 Linear is working fine. I have used it with my SB220 and had no
problems. Well done Elecraft!

73 to all
Dave KD1NA