[Elecraft] [K3] Serial interface noise issues

[Thomas Horsten]

Hi,

I use a cheap USB to serial dongle to connect my Eee netbook (running
Linux) to the K3, but I have a couple of issues with it, and I would like
to solicit suggestions to sort it out.

On 10/12/15m and if the bands are relatively quiet, I get bursts
of S1-S2 static when the PC is talking to the K3, this happens at any baud
rate (at least down to 4800, haven't tried going lower than that). The
problem gets massively worse, S4-S5, if the netbook's power supply is
plugged in, but it's still discernible even without it unless the bands are
noisy. I haven't heard it on 20m and below, but it could just be because of
higher QRN blanking it out.

The other problem is that the serial dongle resets itself when I transmit
on 40m, this doesn't happen on any of the other bands but almost invariably
when I tx on 40m at anything more than 25-30W, even just sending a long dah.

I guess both of these problems could be down to bad/no screening of the
little chip in the dongle, I tried enclosing it and the cable in kitchen
foil but with no discernible difference. Any suggestions, or should I just
get a better dongle and cross my fingers?

73, Thomas M0TRN