At 03:08 PM 4/26/01 +0100, Bill Hider wrote:
>We're talking about making a switching directive array out of GUY WIRES.
>That's a lot of work. So, what is the benefit. That's the analysis.
>A pair of inverted "V"s at right angles will be very simple and manageable.
>Much easier than
>feeding the guy wires. Now that gets into the ballpark of a tradeoff.
>But, at 70 feet, they will have nearly equal performance. The 4-6 dB is
>only at the 30 degree
>takeoff. At higher angles, the front to side drops way off to near
Well, yes, if all you're talking about is inverted vees. I didn't bring
this up before, because a 70' tower isn't tall enough for 80 meters, but a
parasitic lazy vee array (see 8/94 QST) works great for the low bands.
W9LT had one for 80m built into the guy wires of his 125' Rohn 45 tower,
and I have a 4-element 80m wire version hung off my tower at about the 85'
level. The array shows ~4 dBi of gain in modeling, and anywhere from 15-35
dB F/B ratio in practice, depending on the arrival angle from the rear.
Noise performance is excellent for receiving, due to the directivity,
though I wouldn't claim it's as good as a long Beverage. The switchbox is
simple to construct, and dimensions/geometry appear to be relatively
On a 70' tower, one of these could be a good inexpensive 40m solution,
compared to a yagi.
73, Pete N4ZR
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