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[TowerTalk] End-fed antennas

To: <>,"Bill Tippett" <>
Subject: [TowerTalk] End-fed antennas
From: "Tom Rauch" <>
Reply-to: Tom Rauch <>
Date: Mon, 18 Oct 2004 09:15:22 -0400
List-post: <>
>  >          Par Electronics offers the following series of
>  > End-Fed 1/2 wave antennas which require NO radial
>  > and NO tuner.

My point is they can tell you anything they like in the
advertisement but make no mistake about it, the coax is the
counterpoise in that antenna.

What I refer to in power limits is getting away with the
feedline being part of the radiating system. At 5 watts, you
probably won't get RF warts on your fingers if the cable is
the wrong length. At a kilowatt, you could have some serious
RF burns.

I'm a little annoyed that manufacturers claim they can
violate basic rules of electronics. If you have an antenna
that is end-fed, you ALWAYS must have the same current
flowing into a counterpoise as flows into the antenna.
Always. You can get away with a poor system like that at
times, but not always. There are many antennas in that
class. Most are (no surprise) CB antennas like the IMAX 2000
and such.

For portable QRP systems where the radiating feedline is in
the clear, who cares? For more a permanent antenna I'd
certainly do something better. It's not that complicated.

73 Tom


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