On 5/23/2014 3:06 AM, Rick - DJ0IP / NJ0IP wrote:
I agree with all of that, but you leave one point out. "Openwire."
As you well know, the impedance of an openwire dipole varies from band to
band and can be all over the map, up to a couple thousand Ohms.
Rick,
I didn't leave it out at all -- it's one of the non-resonant antennas I
talked about. This is a lousy antenna, a bad idea. Yes, the Handbook
says it "works" on all bands. So does a light bulb. That "all band"
dipole has a pattern that varies widely from band to band, with deep
nulls in some directions where there are stations you would like to work.
The place for antenna match boxes is to make a dipole cut for 80CW work
on the phone band, to load a random long wire that ends in the shack, to
correct for a dipole that isn't quite the right length.
I'm a big fan of fan dipoles, which are easy to build, which work really
well, and which have very predictable patterns. If you have room for a
20M dipole, you can hang a 20/15/10 fan. Barry at Hypower Antenna
Company sells very nice loaded dipoles that also cover 30 and 40 and can
fit 80M into about 100 ft. That was my low band antenna in Chicago. He
makes a version for 160 and 80 with a fan element for 40 that also works
very well on 30M.
73, Jim K9YC
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