Thanks for all the suggestions. Problem is solved now and here's what I
1. Grounded the laptop to the station bus ground - I've always had
grounded my desktops, but it was easy, attaching the braid to one of the
case screws. It required a little thought where to ground the laptop.
I wound up using one of the 2 screw connections on the external monitor
This alone let me go from 200W to about 1 KW before the CW acted back up.
2. Ferrites on the USB serial cable - no noticeable effect.
3. 0.01 bypass caps on all the inputs and outputs of my interface box,
This is a homebrew box for CW, RTTY and voice keying. It uses 4N33
optos for switching and as I never had an RF problem before, I never
bothered with the bypass caps. That did the trick. Full power out, no
Thanks again for the suggestions.
Barry Kutner, W2UP Newtown, PA
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