[TowerTalk] Boom Dipole for 80m?

[K7GCO@aol.com]

In a message dated 10/24/00 12:53:47 PM Pacific Daylight Time, bjk@ihug.co.nz 
writes:

<< 
 Been intrigued by items on operating hf yagi booms as 40m dipoles.
 Anyone tried extending and loading booms to give a rotary dipole for 80m?
 73
 Baz ZL1DD
 
 end
 Barry Kirkwood PhD ZL1DD
 Signal Hill
 66 Cory Road
 Palm Beach
 Waiheke Island 1240
 NEW ZEALAND
 www.waiheke.co.nz/signal.htm
  >>
I'm suggested it many times.  Use mobile antenna hardware.  Use the screw 
diver mobile antennas and a gamma for 80&40M with a coax relay.  There is a 
problem of knowing the exact setting of both.  Better yet use 3 fixed mobile 
whips on each end for 160,80 &40M like the multiband mobile whips do and 3 
gammas. Or use old trapped verticals on the end. You should be able to grid 
dip it at the mast.  If it doesn't dip with the right orientation of the GD 
coil, wind a coil of a few turns with long pig tails and connect to the Boom 
out a ways.  You will need a boom you can tip.  I have a special mast/boom I 
develped to tip and twist the boom.   I will try it in Eznec first on a 44' 
boom 7 element beam and a 24' boom 3 element 20M beam.  I will look for 
balance with the intent to reduce the "Dreaded RF Spill Over" down the mast.  
This will require some differnent lengths on the end.  It's easier to do in 
Eznec.  I've been looking at a 1meg or 1 gig what ever it is, to save 
computer time for several big projects.  k7gco

--
FAQ on WWW:               http://www.contesting.com/FAQ/towertalk
Submissions:              towertalk@contesting.com
Administrative requests:  towertalk-REQUEST@contesting.com
Problems:                 owner-towertalk@contesting.com