[Antennas] Coax Trap: to be or not to be ... this is the question

Wed, 30 Apr 2003 08:02:16 -0400

----- Original Message ----- 
From: "Ed" <[email protected]>
To: "David J. Windisch" <[email protected]>; <[email protected]>
Sent: Tuesday, April 29, 2003 4:26 PM
Subject: Re: [Antennas] Coax Trap: to be or not to be ... this is the
question

> Dave, nice thought if you are looking at commercially made traps. However
as
> far as I know ALL coax traps are homebrew. And just how many companies
make
> traps for sale to the general ham population. Few, very few. Keep in mind
> the original poster asked about 30/40 meter traps. 10-20 meter traps are a
> horse of a different color and are readily available for Yagi's, but not
> dipoles where weight would be a factor. My thoughts
>
> Ed W3NR
> BTW I have no problem with Tom's paper on traps per se, but he could have
> listed the traps he used in his work

Hi, OM:

TU for your thoughts.

Try

http://www.w8ji.com/traps.htm

if you haven't already, for a listing of traps which were tested.

HyGain produced a set of traps for 80/40M which were around 3 feet long
IIRC.

Shouldn't the principles applicable to 10-20M traps apply also to 30/40M, as
well?

Is there something wrong, eg, with the statement that the coax in a coaxial
trap should be treated as a stub because of its physical dimensions?

I have a pile of traps from CC, Mosley, and HyGain.   The heaviest I weighed
were  the Mosleys, at a few ounces more than a pound each.   If you like,
tie a rope catenary between two trees, without and with weights (bottles
with water in them will do nicely) where the traps would go, and see for
yourself the differences in heights.   Then hang the weight corresponding to
the length of coax feeder used, to the center, and see what happens ;o)

73, Dave, N3HE

>
>
>
> ----- Original Message -----
> From: "David J. Windisch" <[email protected]>
> To: <[email protected]>
> Sent: Tuesday, April 29, 2003 6:22 AM
> Subject: Re: [Antennas] Coax Trap: to be or not to be ... this is the
> question
>
>