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[TowerTalk] Re: V-beam Gain and R+/-jX

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Subject: [TowerTalk] Re: V-beam Gain and R+/-jX
From: (David & Barbara Leeson)
Date: Fri, 18 Jul 1997 11:32:06 -0400 (EDT)
I put up a vee beam for 10 and 15 meters, surveying and measuring
carefully, with 10 wavelengths per leg on 10m.  It had about the same
performance as a TH7 on a 38 ft tower, and then only in its best 
direction.  I think the problem was it wasn't cut out for a sloping
foreground situation, given the restricted cone of radiation.

Also, I tried one of the automatic tuners, and discovered that it (and
most of its ilk) must be tuned only at 100w, and that the inductor
wasn't even as big as the old ARC-5 inductors from WWII surplus!  If
you are going to consider an autotuner, read the manual carefully to
see if it will tune at full power (e.g., like an Alpha 87 can do) or
if you have to tiptoe around at low power each time you change frequency.

I sent it back and got a refund, since the box didn't do what the
ads claimed (not even close!).  Most states have a "merchantability"
clause in their commercial code, and the post office is sensitive to
mail fraud in interstate commerce, so a box needs to do what is 
advertised or you have a claim to full refund.

I ended up using a 50:450 ohm transformer to drive the vee, which was
terminated, and the match was fine but the gain wasn't what I hoped
for ("ur S9 on the monobander, S8 on the tribander and S7 on the new
antenna, OM").  Les Moxon has a lot to say about the advantages of
resonant antennas in terms of gain per unit effort, in his HF Antennas

Cheers de Dave, W6NL (ex-QHS)

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