At 11:01 AM 4/6/97 +0000, you wrote:
>If you check my web page, you will see my ideas on feeding a half wave
>antenna. A version was sold here in UK called the Jaguar, which was exactly
>as I describe, viz a tuned circuit with the antenna to the top and a tap a
>few turns from the 'earthy end' for the o/p to the rig. It works well, as
>others have found out and a two band version is possible using separate
>tuned circuits in the same box with sockets for the two half wave wires.
>Radials are not needed, but if you are concerned about RF on the braid use
>ferrite rings on the coax. In practice, as far as QRP is concerned, I have
>never bothered. The tuned circuits are simply adjusted for optimum SWR by
>core adjustment from the outside of the box, a 35mm film cannister us fine,
>and this may need a tweak in the operating position.
>An alternative to all the above is of course an ATU, say an L-match, with
>one counterpose wire. I used this set-up in the last few weeks while in VK5
>and worked some good DX with it, including GM, twice and other EU stations.
>As I wanted to use various bands I didn't use the one described in the web
>page, but have in the past and it DOES WORK!
>Have fun!
>---72/3---Frank G3YCC G QRP 042
>QTHR (Kirk Ella, East Yorkshire)
>QRP Web site: http://www.gqrpclub.demon.co.uk
>
>
>
>The BIG advantage here (with a 'volltage fed' wire) is VERY low ground losses!
The big MINUS is: if you have a Jap solid state rig and run 100-1000 watts,
these
sets are awfully sensitive to stray RF in the shack....which you will have
some of with this arrangement! The old tube/valve gear isn't as "picky" as
these modern "no tune" rigs. I use 3" copper flashing strip as a
ground/earth buss. This generally keeps things "cool".
73
E. V. Sandy Blaize, W5TVW
"Boat Anchors collected, restored, repaired, traded and used!"
417 Ridgewood Drive,
Metairie, LA., 70001
ebjr@worldnet.att.net
**Looking for: 860 tubes, WL-460 tubes**
**Butternut HF2V antenna, G-R test gear.....................***
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