[R-390] Antenna...folded dipole...

[Roy Morgan]

At 03:08 PM 12/15/03 -0800, Kenneth G. Gordon wrote:
>On 15 Dec 2003 at 10:56, Dave Faria wrote:
>
> > GM list.  I want to build a Folded Dipole antenna for my station.

...No folded dipole I have ever seen in antenna books or other
>literature, or that I have built, ever needed a terminating
>resistor.

Ken and others,

I think he meant the Tilted Terminated Folded Dipole, "TTFD" which does 
have a terminating resistor opposite the feed point and is described quite 
fairly at:
<http://www.radiohc.org/Distributions/Dxers/ttfd2.html>

There have been many "animated discussions" (aka arguments) about the 
principles, use, and performance of these antennas.  Some such discussions 
I have read included reports from fellows who use them in VietNam with 
success.  Apparently a commercial supplier made them for the armed 
forces.   (Was it B&W, perhaps?)

As described at the link above, the thing has wide spacing between the 
parallel wires, a non-inductive terminating resistor that dissipates up to 
one third of the applied power, and performs best with a 6:1 balun at the 
feed point and coax transmission line.

I have neither built one nor talked with anyone who's used one.

Roy



- Roy Morgan, K1LKY since 1959 - Keep 'em Glowing!
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