[TowerTalk] [Bulk] F 12 EF 180 .

[Grant Saviers]

Which EF180?  30m is so narrow, and most EF180's so long it should work 
on all of 30m just by tossing the LL wires and shortening it.

For my EF180C (86' tip to tip) for 80m, I removed the LL wires and 
installed a Tornado variable L center coil, replaced many loose element 
rivets with thru bolts, did a Yagi-Mech analysis and sleeved where it 
was going to fail at 65mph, replaced the crappy ABS center insulator 
with machined to fit split colored nylon, sleeved the center with FR4 
rod, and installed Phillystran guys (4) to the former LL wire attach 
points to a stub mast and 6' cross arm 6' above the boom mounting plate 
(made a new HD one also).

Its now a 85 mph design without the element guys and so far so good at 
102' high.  More than full band coverage.

It's now been up 4 years, so far so good mechanically but do have a 
problem with the turns counter reed switch inside the Tornado. Haven't 
dug into this deeply yet.  Using the MFJ1924 manual screwdriver driver 
with the 10 presets at 50KHz steps (it may be the problem with counting 
turns).  Something bad happened when I went QRO way off tuned 
frequency.  The 2:1 bw is about 75KHz.

If it has to come down for a reed switch fix, the plan is to reduce the 
Tornado L by placing some JKantenna plagerized high q coils just inside 
the element guy points.  Then I would probably add a third element guy 
downward to the mast to prevent updraft failure per Dave Leeson's 
recommendation in his book.  btw it is mounted above Dave's 40m Moxon 
scratch build design.

Grant KZ1W

On 1/4/2016 9:59 AM, Wayne Kline wrote:
> All this great  conversation   on the evolution of the  F12 loading  wires  to then  loading  coils and there
>   
> development  . Got me thinking about my Summer 16 project.  I have a F 12 EF180 rotation dipole antenna
>   
>   Having a 4 sq and HIGH dipole , I hope to modify it to 30 meters !!
>   
> I am not sure if Tom ever made  a 30 meter rotating dipole  but if he did  again I assume it's   loading
>   
> configuration is along the  linear loading wire design .
>   
> Might try to adapt the lumped inductor  to the transition  ?   thoughts ?
>   
> Wayne  W3EA
>   
>   		 	   		
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