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Old November 14th 06, 07:58 PM posted to rec.radio.amateur.antenna
[email protected] tclay@qmc.ph.msstate.edu is offline
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First recorded activity by RadioBanter: Oct 2006
Posts: 23
Default Terminating a Rhombic

How's it performing, compared to my standard antenna, a 3 ele SteppIR
at 40 ft? Not so good. At times it is much, much noisier. Never has
the signal strength been stronger on the vee. But wait a minute, it
is not supposed to, it is much too short to qualify as a real vee
beam. The leg lengths are 192 feet, and on 20 meters should be more
like 6 wavelengths long. But it is not supposed to be a vee beam, it
is supposed to be the first half of a rhombic. On with the story.


That length is almost 3 wavelengths at 20m, and should definitely show
gain.

How high is the vee compared to the yagi? Are the wires uniformly high
or do they slope?

What is the angle between the two legs?

Are you feeding it with open wire line? If so, that could be picking up
noise depending on where you route it and your local noise sources.

The vee beam pattern (even at 3 wavelengths) is much narrower than the
yagi, so pointing it is fairly critical. I've used unterminated vee beams
of about that length (150-200 ft), and they were always clearly better
than simple verticals or dipoles in the vee's favored directions, even
on 20m. But I never had a 3 el yagi and vee up at the same time to compare.

Tor
N4OGW