Felipe,
I feed mine (80M vertical delta loop) with 450 ohm ladder line and a Johnson
Matchbox. I use a 250 watt (rated for plate modulated AM) Matchbox and run 1.5
KW into it. Been using it like this for years.
The Johnson Matchbox is probably the most efficient commercial antenna tuner
ever made. Just about all of your power goes into the antenna. Down side of
using a tuner like this is frequent re-tuning as you go up and down the band,
especially when using it on 80. I also use it on 40 and the antenna plays very
well.
Bob
W1RH/6
--- On Mon, 12/8/08, Felipe Ceglia - PY1NB <felipeceglia2@gmail.com> wrote:
> From: Felipe Ceglia - PY1NB <felipeceglia2@gmail.com>
> Subject: [TowerTalk] 80m delta loop question
> To: towertalk@contesting.com
> Date: Monday, December 8, 2008, 5:08 AM
> Hello gurus,
>
> After reading the loop section on Low Band DXing, I decided
> to build a
> delta loop for 80m, mostly vertically oriented, and fed 1/4
> lambda from
> apex. Planning to use ladder line, so I will be able to use
> it on CW and
> SSB portion (PY's are allowed to use only upt to
> 3.8mhz).
>
> The author suggests using 450ohm ladder line for feeding
> it, but I could
> not find much details about it, so I ask:
>
> Which antenna matching configuration should I use at the
> end of the
> ladder line to transform it to 50ohm?
>
> Could I use other impedance on the ladder line, say 300ohm?
> Is it critical?
>
> Would I need a given lenght for the ladder line, or could I
> go random?
>
> 73 and thanks,
>
> --
> Felipe Ceglia - PY1NB
> PR1T team member - Rio DX Group
> http://www.dxwatch.com
> http://skimmer.dxwatch.com
> http://riodxgroup.dxwatch.com
>
> _______________________________________________
>
>
>
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