[Elecraft] K2 key clicks

[Barry Simpson]

Hi 

I have been running K2 #1781 for some time and I have done virtually all
of the mods including the G3VMW "chirp" mod and the fitting of a
decoupling capacitor to overcome the false "hi current"reading on 160m.

However I have recently had reports of key clicks on 15m and so I did
some checks of the keying on all bands using both a dummy load and the
usual antennas.

What I found was that if I run with the power control at maximum there
are quite noticeable key clicks on 160m, 15m and 10m. This is with about
a 14.8 volt power supply. However if I back the power control off a bit
the clicks disappear. It seems like either the PA or driver changes from
linear to non-linear operation at maximum power on certain bands or
maybe develops instability.

Going on from there I also tested the situation using the gel battery I
have bought for portable use which does of course provide a lower
voltage. In that case I also get clicks on other bands with the power
control at maximum power. So the problem seems to be voltage dependent
as well.

Is this a known problem and is there a fix ? Is it caused by any of the
mods I have done ? Or is it simply an indication of my less than perfect
building skills ?

Any feedback would be appreciated.


Thanks

Barry Simpson  VK2BJ