I've gotten to the point where I model ALL conductors in the vicinity,
including coax shields, towers and metallic guys, with appropriate
lumped loads where baluns are used, etc. This would include a boom
with elements connected to the boom if that's how it's constructed. If
it's not connected, move the element up an inch or two to clear the
boom.
I drop a conductor out of the model if it's RF bonded to boom, mast,
tower BOTH at top and bottom. Everything else I layout to its end,
including coax and cables on the ground to the shack.
If you have egg style insulators breaking up a metallic guy, put a
10pf load at the insulator point in the guy to represent the
insulator.
If this is not a Force 12 style tribander (no traps, no linear
loading) modeling the antenna is pretty easy. Traps and linear loading
in a tribander can be a real pain because of the lack of verified
modeling constants.
It's all a nuisance, but if you discover anything it's worth it.
73, Guy
----- Original Message -----
From: "Carsten Steinhöfel" <carsten.steinhoefel@web.de>
To: <antennaware@contesting.com>
Sent: Saturday, February 24, 2007 10:04 AM
Subject: [Antennaware] Modeling antenna interaction
> Hello,
>
> I want to model interaction between a Tribander and a 40m-Antenna on
> the same mast.
> I can model both antennas and make sure that the wire elements align
> of course. Is
> this alone a sufficient test, or do I have to model the seperated
> nature of the
> feedpoint of the antennas - or the coax as a transmission line
> (grounded or open)?
>
> Thanks in advance for any tips.
>
> vy 73 Carsten, DL1EFD
>
> _______________________________________________
> Antennaware mailing list
> Antennaware@contesting.com
> http://lists.contesting.com/mailman/listinfo/antennaware
>
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