I can recommend the 80m JK801 rotatable dipole.
I have one at 138' and so far so good. It's only been up since July so
I'm looking forward to the fall/winter DX season. The antenna does not
use coils, it uses T-hats towards the ends. There isn't much droop to
it(note there is no truss cable) and it has handled the winds here in
Amarillo nicely.
There's a picture of my JK stack on my qrz page. The dipole is at the
top followed by a Mid-Tri Tribander, JK3040SR 40/30 yagi, another
Mid-Tri and finally a F12 WARC 2/2 at about 55' to cover 12/17. I'll
probably add another Mid-Tri when 10 meters is more active.
The only interaction I've had is on 20m, I had to move the JK801
parallel with the other booms to fix the 20m swr issue. At the time of
installation the tornado tuner was not active. I'm going to climb the
tower and have a buddy monitor the 20m swr while I move the JK801
parallel with the elements.
Each half of the JK801 is 27' long and with the T-Hat it probably acts
as a half wave on 20m. I'm hoping with the tornado tuner on line, that
the 20m portion of the upper Mid-Tri won't be affected. I'd like to get
this resolved from an SO2R stand point. More than likely propagation
will be coming from the same direction on both 40 and 80 which requires
both antennas to be pointed in the same direction vs a 90 degree offset.
I've worked lots of DX on FT8 with it along with some phone and cw.
I can cover the entire 80m band from below 3.5 mhz to above 4.0 mhz via
the tornado tuner and the mfj-1924 controller.
I have the following swr bandwidth as follows:
- 1.5:1 40 khz
- 1.75:1 60 khz
- 2.0:1 80 khz
I use 5 of the MFJ memories to cover cw and 5 for SSB then fine tune if
needed with the up and down buttons. I may change that to 4 on CW and 6
on SSB.
Rich - N5ZC
On 10/8/2017 6:32 PM, Bob K6UJ wrote:
Hi John,I'm assuming you want a loaded shortened dipole.
I would suggest contacting JK Antennas and ask Ken to fab two of his loading coilsfor a
shortened 80M rotary dipole. His loading coils are outstanding. Made with
solid
aluminum rod, not tubing, and the connector blocks on the end of the coils are
welded on.Less connection worries. Take a look on his website at how he makes
these loading
coils, very impressive. For that matter ask him about a complete 80M rotatable
dipole if you aren't making one yourself.
I wish my tower would handle an 80M dipole along with the existing load or I
would
be thinking of doing an 80M dipole too.I have a 4EL 20M yagi at 108 ft and a 3EL 40M yagi at
96 ft. That will be my upperband antennas during the low sunspot cycle years. I
have an 80/160 dual band
inverted L to cover these bands.
BobK6UJ
From: john nistico <electric911inc@hotmail.com>
To: towertalk <towertalk@contesting.com>
Sent: Sunday, October 8, 2017 12:19 PM
Subject: [TowerTalk] 80 Meter yagi question
So my Virginia towers are almost completed and most of the antennas are ready to install. I am thinking of adding a rotatable 80 meter yagi on one tower. Any suggestions?
John J. Nistico
911 Electric Inc.
516.325-8993
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