A FULL SIZE 3L20 on a 24 ft boom MAY achieve 8-8.5 dBi gain.
That is 6-6.5 dB over a dipole. And you believe the little A3
on a 14 ft boom might have the same gain in 20M? NO WAY.
A FULL SIZE 3L20 on a 14 ft boom MIGHT achieve 7-7.5 dBi
or 5-5.5 dB over a dipole (with NO traps). See the W2PV
Yagi Design Book, Chapter 2, for graphs of 3L Yagi gains
vs element tuning and boom length.
I'm not saying the A3 and A4 are bad antennas, only that I
seriously doubt the ADVERTISING CLAIMS.
Tom N4KG (RF Engineer)
On Fri, 29 Nov 2002 (PST) "Michael Hatzakis, Jr" <mikehatzakis@yahoo.com>
writes:
>
> Just moved to the seattle area and am assembling a new station.
> Possibly an MA-550 55' tubular tower with a 10' mast. Trying to
> decide between two classes of beam, in roughly the same price range
> are the Cushcrafts and the Force 12's.
>
> The Cushcraft A3S/A4S 3 and 4 element standard trapped beams claim
> 6db gain (3ele) and 7db (4ele) over dipole. And the Force 12 2
> element beams running around 4.5 db. The 3ele cushcraft and the
> force 12 have about the same dimensions... They have about the same
> windload, 5sq ft for the tubular..
>
> Any thoughts on pro's and con's of the two antennas? experiences?
> The cushcraft is 3db high gain, but is it lost in the traps?
>
> Thanks, Michael K3MH
>
>
> Michael Hatzakis, Jr MD
> Physiatrist, Treating Individuals with Neuromuscular Disabilities
> Consultant, Information Technology Based Health Care Solutions
>
>
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