I had recently gotten a "new" preowned omni 6 which I hooked up to a 40
meter windom antenna fed with ladder line fed 1/3 from the end and using a
current balun. The feedback on phone was so bad that the radio could not be
used. I found out that by using an rf current meter there was almost .8 amp
of rf current on the shield of the coax comming from the balun and also the
same current in the ground wire. Needless to say that no matter how I tried
to ground the radio, it left the radio rf hot. However, when I included an
RF isolator between the antenna tuner and the balun, the rf current dropped
to zero and the radio as well as a 1.5kw linear worked perfectly.
Make sure you don't have a lot of rf comming back into the shack on the
outside of the feedline. My ICOM never minded it, but the TenTec sure does.
Tom Reilly
W3GAT
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