I use a Tornado on a re-engineered EF180C 86' 80m dipole. Only takes
one with the coil split at the center. Replaced the LL with Phillystran
and internally sleeved it where YagiMech said it was weak. Now 90mph+.
Covers the full band.
There was a CO antenna builder who was going to make a 80m beam with
Tornados. It should work if one can keep track of the inductance
settings per the modeling. That should be straightforward with AutoEZ.
Grant KZ1W
On 2/16/2020 08:16, Jim Thomson wrote:
Date: Fri, 14 Feb 2020 13:23:30 -0600
From: john@kk9a.com
To: towertalk@contesting.com
Subject: Re: [TowerTalk] 80 meter antenna advice. (NY6DX)
<That's funny Jeff:) In reality an 80m beam can be built strong enough
<to survive the midwest. I had a homebrew linear loaded dipole with a
<90+ ft element 160' high that held up well in Chicago. However if you
<want to operate both CW and SSB, you will need relays on the elements
<which can be problematic and difficult to maintain.
<John KK9A
## Heres where loaded elements would be a huge asset...to minimize max
ele length .... which can be made
stronger....vs a full sized ele. T bars, aka capacity hats would be a
good loading scheme. That plus
loading coils, just inboard of T bars. The remaining loading, and
ability to switch from cw to ssb
can be done with fixed coils and a mess of relays.... or a seco
systems tornado drive..which is just
a pair of compressible, plastic coated, .25 inch od copper tubing
coils. The seco uses an ameritron SDC-102 screwdriver
controller, 12 vdc, to expand and compress the coils. Comes with a
digital readout turns counter..and 10 x pre-sets.
Tornado drive installed at feedpoint of each ele.
## If relays are used, use gigavac SPDT G2 type ceramic vac relays,
or Taylor brand V2 SPDT ceramic vac relays... available
in 12 vdc or 26.5 vdc. If mech relays have to be used, use DPST
types, with contacts in parallel...... for redundancy.
Jim VE7RF
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