[TowerTalk] wires in trees

Jim Brown jim at audiosystemsgroup.com
Tue Jun 28 12:23:50 EDT 2005


On Tue, 28 Jun 2005 12:06:49 -0400, Jim Jarvis wrote:

>Incidentally, extending the dipole to 132', to get it to halfwave
>on 80m may make it hard to tune on 40 and up.  

I am a huge fan of fan dipoles -- parallel wires connected to the 
same center insulator/balun. On FD, we use a fan that covers 80 and 
40, and others that cover 20/15/10. Each are full size half waves on 
their respective bands, a decent match is achieved on all bands, and 
they are less lossy than using traps or loading coils. 

These are easy to build, and they are inexpensive. All you need is 
wire (from Home Depot or equivalent), a few sticks of PVC conduit 
(from your local electrical supply), and the center insulator/balun. 
I use spacers made by cutting 1/2" PVC conduit into 15" lengths for 
3-wires and 8" lengths for two wires, then drill holes for the wires 
1/2" from the ends (and at the center of the 15" spacers). I've 
built about ten of these for various bands using the DX Engineering 
dipole balun (now discontinued), which was designed in a manner that 
made it very easy to do very rugged and electrically good 
termination. I don't know what I'll use the next time I need to 
build more. 

Jim Brown  K9YC




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