On 9/30/2017 6:56 AM, Chuck Dietz wrote:
With a fan dipole, research sponsored by the military showed that it helps
if you can spread the dipoles apart about 8 to 10 inches at the center. I
have a piece of plastic about two feet long and about 8 inches wide that I
drilled holes in for each wire and for a u bolt for the balun. A wire runs
between the holes on each side to connect the dipoles.
I wasn't aware of that work, but it makes sense, and mirrors how I build
my fans. My first spacer on each side is within a foot or so of the
center insulator, so that the wires run diagonally from the insulator
and thus become separated for all of their length. There are photos of
two of my fans, one for 80 and 40. another for 20, 15, and 10, on pages
26 and 27 of
http://k9yc.com/LimitedSpaceAntennasPPT.pdf
73, Jim K9YC
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