I'm planning on putting up a 160m Inverted L along with the K2AV FCP. I'm aware
of the other options for radials, etc. but for my particular situation the FCP
seems to be the best option. I also will be supporting the L from the tower
which I know is not the best plan but, again, it's the best option for my
situation. My obvious goal is to reduce the interaction and losses from the
tower and other antennas as much as possible. I have a number of questions.
My Planned setup will be:
Self Supporting Crankup Tower at 60' with a Steppir DB-18 (40m-6m) at
~62'.
L Bend supported at tower top.
Horizontal wire will be at 50-55 ' running to a separate mast or tree.
80m inverted vee supported from tower on opposite side from the L (this
might be eventually eliminated if I end up also using the L as EFHWL on
80).
Coax and control lines will run down the opposite side of the tower on
support arms.
Using the info suggested on the K2AV website, I plan on placing the vertical
wire per the suggested dimensions (3' out from the top of tower and 10'-13' out
from the bottom) as well as using a common mode choke at the 80m inverted vee
feed point to reduce losses from the tower and coax. The FCP will be 8'-10'
high as suggested on the web site.
Questions:
1) In addition to the feedline choke on the 80m antenna do I also need
one on the Steppir?...I have seen some comments that fully
retracting the Steppir elements will reduce the interaction from
the antenna itself but there is still the coax feed to possibly
deal with.
2) Is one feedline choke at the antenna feed point sufficient or
should a second be employed at the base of the tower where I have
lightning arrestors installed before the coax goes underground?
3) Do the rotor and Steppir control lines also pose a loss
problem?...How should that be handled....toroid sleeves?...at both
top and bottom of tower (before the cables go underground) and
again, at the lightning arrestor point?
4) The K2AV website suggests hanging the L 3' out from the tower at
the top...would a greater separation distance be
advantageous?
5) I have an existing (but not very good) radial field attached to the
base of the tower. It's my understanding that the radials should be
disconnected from the tower to employ the FCP...is that correct?
I'm sure there are other things to consider that I haven't thought of. Any
suggestions or comments from others with similar setups will be appreciated.
73's,
Bill, AA7X
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