12-01-2018, 11:52 AM
(11-01-2018, 04:16 PM)VK3PY Wrote: Wayne,
You haven't given much of a description your your station layout or computer set-up, but here's a suggestion. Could it be that you have a loose connector or poorly-terminated connector on the 2m feed line, either "upstairs" or in the shack? This could result in plenty of RF floating around in the shack if the co-ax shield is not making good contact.
Chas
VK3PY
Hi Chas
You were right, but firstly I will describe my system.
Antenna is a log periodic yagi covering 6m to 23cm. A single flexible coax line attaches to a length of heliax down to the shack wall where it connects with another flexible coax line (via lightning protection) through the wall to a coaxial switch and patch line to the FT847 and the 23cm transverter.
I checked the antenna a couple of weeks ago and the connectors, switch and lines inside the shack yesterday - no problems found. When I checked the connector between the heliax and the line going through the wall I found that the inside of the plug was lightly corroded. Attached a new one and the problem with the computer was resolved
6m (100W), 2M (50W) 70CM (50W) and 23cm (10W) RF power all passed through the same plug but only 2m caused the problem. The other interesting point is that there was no discernible change in 2M SWR.
Funny stuff RF!
Wayne VK4WDM