[TowerTalk] wire beams vs. aluminum / coax choke balun / stacking distance

CP2235@aol.com CP2235@aol.com
Thu, 6 Nov 1997 13:37:10 -0500 (EST)


I might be able to put up a 3ele yagi for 10m and a 3ele yagi for 15m for the
WWDX contest.
Those will consist of a very light arrangement made out of a fiberglass boom
and fishing rod "elements". Those fishing rods will carry the wire beam
elements. So those yagis will be more ore less wire beams. 
I plan on using 1mm  (39 mil) diameter (or 18 AWG) solid copper wire for the
Does anybody have something against that? Should I use a thicker wire because
of lower losses? AO/Necwires models it just fine.

2nd question: I would like the "coax-coil RF-choke" as a balun. How many
turns should I coil up for an effective balun on 15m / 10m? I plan on using
RG-213 as a feed line, so the minimum diameter of this coil will be about
23cm (9 inch). What is the best diameter for this coil?
Are the coil data different for other frequencies or can I use a choke like
this for 160 to 10m?

3rd question: I might stacke the two 3ele yagis for 10 and 15 on the same 10m
(33ft) pole.
I plan on using 1.5m  (5ft) stacking distance, or is it too little? AO
modeling says it is OK. 

Thanks for your help!
73 Con DF4SA                     Cornelius Paul

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