Topband: Four Square

Adrian Rees (MW1LCR) rees.a at btconnect.com
Sat Jul 22 13:46:43 EDT 2006


Hi all

First of all, many thanks for the extremely helpful advice you have all
offered, both on and off list.

After giving this some thought, I am going down the route of de-tuning the
towers,(instead of isolating the towers) and modelling the potential
solution. At this point, the actual towers havn't been installed, although I
have permission to install them. They MUST be in a square formation, but can
be between 20 and 50 m apart. Each tower will support various
Yagi's....So.....

I am using MMANA to model a 4 Square on Topband, and need some help.

Although I have a working 4 Square file that MMANA can use, I am puzzled how
to model the effects of the metal supporting towers in MMANA.

Background:


Now then, I plan on running a catenary wire (well, rope) from the top of
each tower to the next one. This will support a T aerial, fed against earth
(or elevated radials). The vertical part of the T will be 80 feet, the
remaining top part of the T will be about 40 Feet a side. This seems to work
FB in Freespace in MMANA.

What I need to do is to model the effects of the supporting towers. I am
particularly interested in the effects on the radiation pattern / angle.

The plan is to de-tune the towers with Gamma Rods with either Capacity or
Inductive loading.

Question is, how far do I de-tune them, given that an 80 M 4 Square is
planned as well.

Thanks


Any help ?
Thanks

Adrian Rees MW1LCR




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