[TenTec] RF gets into computer

[John K Gotwals]

The following two steps seem to have solved the problem I had on 75 meters, 
at least when running the Orion barefoot.

1) Ran #12 wire through the 2nd-story window sill and down to a 10 feet long 
copper clad ground rod. The length of the wire run is about 15 feet. While 
this may seem to be an obvious step, at my previous QTH the use of an earth 
ground made RF feedback problems worse on some bands.

2) Installed an Amidon FT-240-77 ferrite toroid as a common-mode choke (11 
turns) in the Orion's DC power supply cable and located about 18" from the 
Orion. I am using an Astron RS-35A linear power supply (the fan on the 
Ten-Tec switching PS was too noisy). The cable run between the power supply 
and the Orion is somewhat lengthy because the Orion is connected to an 
MFJ-1129 multi-outlet strip.

Step 2 above seems to have also corrected an occasional "flakiness" in the 
operation of some of the front panel controls, which I had blamed on 
progressive failure of the RIT/XIT encoder. For some inexplicable reason, 
the computer problem I had with the USB connected keyboard has disappeared 
with the installation of the Orion's power supply cord toriodal filter!