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Sat, 23 Feb 2008 13:20:57 -0600 |
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Yes, the frequency is in mhz, and the formula is the same as for a 1/4 wave
antenna, as that is exactly what you are building here anyway.
Thus, for a 40 meter counterpoise, divide 234 by 7.150, or whatever
frequency within 40 meters you want.
A quarter wave is fairly broad, so cut for the middle of whatever band, and
go with it.
In order to "tune" the counterpoise, you would need access to a meter which
would measure rf current in the wire, and then trim for maximum current.
That's a bunch of trouble, especially for us. I've never known of anyone who
found it necessary to tune one beyond the formula length. As I said in my
first message, I found that if you are anywhere near the resonant length,
you will notice the tuning improvement.
Mike Duke, K5XU
American Council of Blind Radio Amateurs
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