Topband: L/FCP Design Questions

[Bill Eisinger]

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