[Elecraft] K3 CW Chirp

[Lee M. Dziekan]

During the 2009 CQWW CW contest, I got a report of severe chirp from one of
the stations I worked.

I turned on my OMNI 6 to listen to my signal and there definitely was a bad
case of chirp.

I confirmed this on 15 meters, 20 meters, and 40 meters. 80 and 10 showed no
issue.

External KW amp on or off did not make a difference.

 

I use the K3 12VDC OUT port (0.5 A MAX Switched) to drive antenna switching
relays and the control circuit (CMOS BCD to decade decoder)

that is driven from the K3 ACC port.

 

To solve the chirp, I used a couple of clamp on ferrite cores on BCD output
from the ACC connection AND the 12 VDC OUT.

Remove the cores, the chirp returned.

 

I have not yet tried to separate the BCD signals from the 12 power to
determine if suppression is necessary on one or both.

 

FYI

 

Lee

N8LJ