[TowerTalk] Fan dipole construction methods

[Grant Saviers]

I built a pair of 80/40/20 fans set at 90 deg to each other and was 
quite happy with them at 65'.  Good F/S.  I used EZNEC for the design 
and it was close, but for the modeling be sure to follow the advice of 
Cebik re modeling repeated in the example by Dan at ac6la.com  As built, 
mine was close enough to the modeling.

For the center insulator I used a 4 x 12 x 3/8" acrylic so the centers 
were separated by 5".  The ends were separated by 30" with some square 
3/8" pvc rod.  Parachute cord was used to tie the ends of each dipoles 
insulator to the 80m end insulator.  This gets to be a real confusing 
collection of wire and cord so they get wound up when taken down on a 8" 
diameter 4' long piece of concrete form tube.

After being replaced with other antennas at my QTH, the 20m element was 
removed and one tuned for cw and the other ssb and they are now club 
Field Day 80/40 antennas.  Rolled on the tubes, they have gone up and 
down for several FD's.

Grant KZ1W

On 10/1/2017 5:50 AM, N1BUG wrote:
>> I would not recommend a parallel/fan dipole with 80/30 meters.  I've
>> tried it several times and the 80 meters wire detunes 30 meters.  The
>> antenna works as badly as if one simply used a tuner to force power
>> into the 80 meter wire.
>
> Thanks Joe. That makes sense.
>
>> The better "solution" for fan dipoles would be two fans - one for
>> 80/40 and one for 60/30 where one has a harmonic relationship between
>> the two bands in the antenna.
>
> That would be attractive and reduces ropes considerably over single 
> band wires. I just need to find a mechanical approach that works.
>
> 73,
> Paul N1BUG
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