[UK-CONTEST] OT: 20m Trap design

[Fred Handscombe]

James

There are articles on the coax cable traps in both the ARRL Antenna book
(20th ed) and the ARRL Handbook 2006 edition

The article mentions W8NX so you might try Googling his call?

The original articles were in QST and might be accessible via ARRL web site?

73 Fred
G4BWP

----- Original Message ----- 
From: "James Hill" <jrh at g0fhm.net>
To: "UK-Contest" <uk-contest at cd ARRL handbook 2006 versionontesting.com>
Sent: Saturday, November 01, 2008 3:53 PM
Subject: [UK-CONTEST] OT: 20m Trap design


>
> Hi Guys,
>
> I know there are some good antenna brains on here.....
>
> Basically, my 40m Carolina Windom is shot (havent got it down for
> autopsy yet), and I'm looking to replace it with a 20m vertical (half
> wave CB type at the correct length, with the matching unit removed from
> the bottom).
>
> However, my 80m inverted L does not seem to work too well on 40m (tunes
> up at 1:1), but appears to be terribly inefficient on both TX & RX.
> Works fine on other bands (even managed to work 3B7 on 17m with it!).
>
> What I plan to do, is something along the lines of the "battle creek
> special", and put a 20m trap on the top of the vertical, and extend it
> with wire to the top of the tree at the bottom of the garden, to make it
> good for 40m too.
>
> I've googled for trap designs, and got designs for virtually every type
> of trap, except the type that I want!
>
> I've read a lot about coaxial traps, and that appears to be the way to
> go, as I have drum after drum of RG58 here that I will be able to use.
> Power wise, then 100w tops will be the order of the day, no QRO here!
> Although an LC type trap will be considered, if it's quite easy to make,
> and I have the required capacitors kicking around.
>
> Any thoughts? and more importantly, links to any designs would be
> appreciated!
>
> Thanks,
>
> James G0FHM
> _______________________________________________
> UK-Contest mailing list
> UK-Contest at contesting.com
> http://lists.contesting.com/mailman/listinfo/uk-contest
>
>