----- Forwarded Message ----
From: "paul@..." <paul@...>
To: ALEX LISTER <alexcom22@...>; "uk-contest@..." <uk-contest@...>
Sent: Tuesday, 31 March, 2009 9:05:13 AM
Subject: Re: [UK-CONTEST] 23 cms Antenna help pse

ALEX LISTER wrote:
> At LRS we have a long  Yagi for 23 cms, Approx abt 5 metre or longer.
> Think its WILMO or possibly Tonna
> Conventional elements ie not JVL loop.
> Elements are made from enamelled copper wire.

It sounds like a 55 elememt tonna.

If the elements stand off the boom on little plastic supports, maybe 40mm long then its a tonna.

A very good antenna, When I was in IO83 I used four in a box pattern for many years.

But once they have been in the sun (uv) for a season, the plastic element supports become very brittle, anything bigger than a starling will break elements off. I ended up sweeping the elements up off the drive. For that reason alone I wouldn't buy them these days. Driven element only rated 300W although even at much higher powers never had any issues.



From behind the mountains here I use a 2m dish rather than yagi's - but *if* I were in the market for a ready made product: Wimo make a range of SHF yagis that use a modern optimised design and are far more robust than the old Tonna. Sadly the economic downturn means antennas bought in Euro's are very expensive.

-- 73 de Paul GW8IZR IO73TI
http://www.gw8izr.com