Another factor to consider is arrival angles and I don't know if HFTA
has data for V31 region. That would matter a lot for contesting (maybe
25+ deg EU and US?), but then lower would be better for DX into Asia/VU.
I have to wonder if K3LR's e4sq vs dipole experience is related to the
angles into WPA from EU. With the dipole so high it's peak angle might
be too low vs the 4 sq.
I second the comment that an inverted V hanging on a tower with Yagis
can have interaction problems, at least this was true with my modeling
attempts to get an 80m pattern with some gain below 10deg which is the
EU arrival stat into WWA. My 86' rotatable dipole at 102' feet couldn't
do the job. A JK 2L yagi at 157' solved that problem for me, more gain
db's and lower angle db's, >6 total. For a rotatable large antenna, JK
knows how to make them that last.
Grant KZ1W
On 7/7/2020 12:39, Richard Thorne wrote:
Bill,
I've been real happy with a JK801 rotatable dipole at 138'. I use a
Green Heron RT-21dc (the other option is an MFJ-1924 mobile antenna
controller) to control the Tornado Tuner. It gives me full band
coverage in 40khz increments.
According to Ken's modeling (unconfirmed by me as I have no clue how to
model) a JK801 at a 1/2 wave length in height is at least equal to a
good 4 square.
https://jkantennas.com/jk801.html
Rich - N5ZC
On 7/7/2020 9:50 AM, Bill via TowerTalk wrote:
I've pretty well figured out what I will be doing on 40-6 meters.
However, 80 is still undecided. Shunt feeding the tower is not going
to work since I have all kinds of rotating antennas up the side of the
tower. So, I'm left with three solutions.
Since the last guy point is at 96 ft I could have two inverted Vees
apexed at 96 feet down to around 60 ft on the ends, at right angles to
each other. That would give me the ability to switch directions and
gain/lose around 5-10 db.
Second choice is to have a full size wire vertical with 60 full sized
radials over average ground.
Third choice is more complex- a wire 4 square but...although the SE
and SW facing verticals would be pretty close to having a good radial
system The NE facing one is pretty limited due to lot lines and the
location of the house/garage and the NW facing antenna is even more
limited by the same constraints. This one has a driveway in the way.
Most of the decent sized radials would be pointing away from the
direction the NE and NW are facing and the others would be fairly short.
Of course laying down the radials for the 4 square is quite a chore
and I would hate to go through all that work to come up with crappy
system. Easiest of course, would be the inverted Vees. I've used
this system in the past and it performed quite well. I'm concerned
the lack of similar radial systems would ruin the F/B and gain and the
compromised radial system of two of the antennas would also be an issue.
Your thoughts?
Bill KH7XS/K4XS (soon to be V31XX)
Location of the station is V31 and interest is contesting and DXing
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