On 9/10/2013 7:20 PM, Larry Bryan wrote:
but I did discover when I took the
Tecsun outside that I have a large noise from the dipole coax. If I get
anywhere near the lead in, the radio goes full scale. Same type noise I'm
hearing on the Flex.
That may or may not mean anything. Inside the portable radio is a loop
antenna, and it will usually couple to any wire passing by it, which
couples any signals (and noise) current on the wire into the radio.
One thing to check -- look carefully at the Flex radio and make sure
that the body of the coax connector for the antenna is screwed down to
the CHASSIS.
My antenna is a Tennadyne TD-90HP800 folded dipole in a inverted V
configuration.
Ah, the famous dummy load antenna -- that "termination" burns half of
the TX power on some bands, which is how the antenna gets to be
"broadband."
Coax goes into a balun at the feed point of the antenna. The
balun is part of the antenna package.
There are at least a dozen different things that are CALLED a "balun,"
and they all do very different things. The "balun" that came with the
antenna is probably useless. Many commercial "baluns" are.
Just looking for some feedback on this issue.
What you NEED up there is not a magic box called a "balun," but a
serious common mode choke. Study http://k9yc.com/RFI-Ham.pdf and use
the Cookbook to tell you how to build what you need. I suggest one of
the bifilar types.
I also suggest you build a much better antenna -- that dummy load is a
loser.
73, Jim K9YC
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