Re: 10m antennas

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From: Dennis Henderson (Dennis.Henderson@Eng.Sun.COM)
Date: Fri May 07 1993 - 19:28:36 EDT


>
> That's weird. A "pure" horizontal dipole is around 70 ohms and should load
> fine with 50 ohm coax, IF the dipole antenna itself is indeed resonant at
> the frequency in mind. I suspect maybe it was not and required some pruning.

I pruned and extended and could not get a good load.

> Going by the formula "468/freq. in MHz" may not apply in your case if there
> are too many surrounding objects and, perhaps, the antenna is too low to the
> ground.

Bingo ^ 2. The antenna was very close to the ground. It was about 10 feet
off the ground. The final resting place was in the attic which was in
close proximity to many objects.

>In any case, drooping the wires to 45 degrees does indeed reduce the
> feed impedance to 50 ohms.

Simple, immediate fix.

>
> By the way, what WAS the SWR when the antenna was horizontal?
>

Would not load...3+.

...Dennis Henderson, N6TTW


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