Thanks Alberto.

I tried the 850MHz P3 laptop and it works fine. Obviously the 200MHz machine
is not good enough, I will have to upgrade the shack computer :-(
I made a very weak signal and listened to it on a live receiver so it was
against real band noise. A problem seems to be that there will always be a
Loran line in the window so the system has trouble decoding if the wanted
signal is weaker than the Loran line. We'll have to see how this works in
practice.
Thanks for the tip about the receive window, very useful!
My shack PC is in 800x600 with no problems .
I have made a few test transmissions at low power, so if anyone wants to try
it let me know and I'll send a beacon signal on 137.5.
Or even a QSO?

73.
Dave
G3YXM.