[RFI] Another Solar Panel RFI System

[Jim Brown]

On 12/25/2022 6:23 PM, James Gordon Beattie Jr wrote:
> The other day I was running 600W on a dipole close to the ham shack on 40m and 80m and a newish Evolve III laptop had its touchpad lock up or randomly "left click" when I was transmitting.  My desktop machines and other laptops, an HP and  Dell have no issues.  This is a "new" problem that will probably get addressed when I move the dipoles in a week or so as planned.

It might also get addressed by filling in any holes in bonding in your 
station. Laptops are tricky, but we SHOULD be able to get to the chassis 
with the shell contact of I/O connectors if the mfr didn't screw that 
up. The most convenient is the D-connector for video, if it has one, but 
it should be possible to sacrifice a well-made USB cable and hit the 
chassis. :) With D-connectors, I slip a small lug with a wire soldered 
to it under the retaining screw.

K6XX and I experienced RF feedback from our antennas to our K4s via a 
boom headset plugged into rear panel jacks that are not bonded to the 
chassis at the point of entry. It is QUITE bad -- I experienced it when 
setting up the the 10M contest, with my TX antenna 200 ft away and 120 
ft up, pointed with its back to the shack. This is a classic Pin One 
Problem. Symptom is that the rig chatters into and out of TX as soon as 
you plug the mic in. To make it work, I had to throw a half dozen or so 
ferrite chokes on stuff plugged into that rear panel.

Each time I've visited mfrs booths at Visalia and Dayton, I've studied 
the rear panels of their rigs to check for this defect. I've yet to find 
a rig that didn't have the defect at most or all of their accessory I/O 
connectors. Elecraft got it right for most of the connectors on their 
KX3 -- the mic connector is bonded, but I/O for control are not. Last 
time around for that was spring 2019, at Visalia.

73, Jim K9YC