On Mon, 25 Feb 2008 22:54:48 +0000, RICHARD SOLOMON wrote:
>What would you suggest I use to match 50 ohm coax to 450 ohm twinlead ?
>I'm thinking of putting up a 160 dipole.
Why twinlead? A low dipole is pretty close to 50 ohm coax and a high one
is pretty close to 75 ohm coax. Then all you need is a good common mode
choke at the feedpoint, and you'll have a relatively quite antenna and a
good match for at least 60 kHz of the band. Any good antenna tuner will
match it to the transmitter over the rest of the band.
If you're feeling rich and MUST buy a choke balun, the DX Engineering
chokes and baluns are excellent, and are worth the money (and nothing else
is even close). But they're expensive (about $130), big, and far too heavy
to hang at the feedpoint of a dipole.
See http://audiosystemsgroup.com/RFI-Ham.pdf for simple instructions on
how to build your own common mode choke (what some call a current balun)
for about $30 that will be as good as the DXEs, and a LOT less weight.
Jim Brown K9YC
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