Hi Bruce,
The only way for the bandwidth of an inverted L to be broad is if there are
excessive losses.
If you measure the resonant impedance at the feedpoint and compare it to the
known radiation resistance of the antenna, you may see why yours is so
broad....unless we aren't talking about the same antenna. Any 1/4 wave
vertical that shows very broad VSWR is operating with very high
losses...there is no other way to get broad band performance out of a
standard 1/4 wave vertical, as far as I know.
You might provide the details of your "coaxial" inverted L's....if they
follow the pattern of the double bazooka dipoles, then we know that it is
losses that account for the broadbandedness...but in any case, it will be
interesting to hear what exactly you are doing. Please tell us more.
73,
..hasan, N0AN
----- Original Message -----
From: <wa3afs@inav.net>
To: <towertalk@contesting.com>
Sent: Thursday, July 13, 2006 4:20 PM
Subject: Re: [TowerTalk] Question on Multiple Inverted L Antennas
> Please be aware that the bandwidth for a coaxial inverted L is very broad.
> My SWR at 1.800 is 1.3 and slowly rises
> to 1.7 at 2.000Mhz. (The antenna is cut for 1.8400MHz and is physically
> located about a foot away from the base
> plate of one of my 80M coaxial inverted Ls). Because of my phasing
> system, It is not easy for me to measure the
> SWR curve from the shack for my 80M, 40M, or 20M coaxial inverted Ls, but
> I remember that the curves were
> decent for all of them when I installed them.
>
> 73
>
> Bruce, WA3AFS
>
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