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Sun, 21 Mar 2010 17:45:51 -0400 |
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Hey Phil!
Thanks for the info. I'll try the numbers and see what happens.
73, Albert, W A 7 F X B / 4
Greenville NC
EchoLink node: 75240
----- Original Message -----
From: "Phil Scovell" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Sunday, March 21, 2010 1:31 PM
Subject: Re: 4 element 10 meter beam
> The driven element is adjusted by using 468 divided by the frequency in
> MHz.
> For example, 28.3 MHz equals 16.54 feet. That old of an antenna probably
> used a gamma match but it could be something different. If it is, the
> driven element will have an insulator keeping it from touching the boom
> and
> dividing the driven element into half with any variety of tuning systems.
> If it is a gamma matched antenna, even the driven element will be bolted
> directly to the boom. The directors are smaller by, I believe 4 percent
> so
> the one on the very end will be much shorter than all the other elements.
> The reflector, the element on the other end, will be the longest and is 5
> percent longer than the driven element. Spacing is based upon quarter
> wave
> spacing from each other unless it is wide spacing. With a 16 foot boom,
> however, it won't be wide spaced elements but standard. These are the
> basics. There are all types of variables based upon the type of antenna
> it
> is.
>
> Phil.
> K0NX
>
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