[TowerTalk] Mounting 2/440 beams on tower
n7xy at clearwire.net
Sat Jul 4 13:28:54 PDT 2009
You probably will have issues doing that. If you could select coax
lengths between the tee such that each beam which would present a
very high impedance at the tee on the other band, it would probably
work. One of the problems in doing that is that since 440 is three
times the 2 meter frequency, the 2 meter antenna will probably have a
reasonable match and you cannot get enough isolation with just a tee
connector and a length of line. You could use a combination of high-
pass and low-pass filters but I suggest that you get another diplexer
(not duplexer, by the way) and use it to split the feed to the two
beams (which is really doing the same thing, plus it wouldn't be
sensitive to the length of the coax feeding the beams).
On Jul 4, 2009, at 12:02 PM, AD5VJ Bob wrote:
> I have a question about mounting my 2m/440 beams on my tower.
> Presently I have up only a dual band vertical that I use with my
> Kenwood TM732A from a duplexer.
> Now that I have separate beams for 2m and 440 and want to mount
> them on my mast on my 30 foot Rohn 25G tower.
> I want to mount the beams on the tower. I want only one coax coming
> into the window from the beams. I want to switch between the
> vertical and the beams while scanning both bands.
> Can I simply:
> Install an SO-239 T or N connector T at the tower.
> Feed the T to the antennas and back to the shack through my tower
> mounted remote switch to a two position switch at the shack which
> would switch between tower and vertical.
> Run the output of the switch to the input of the duplexer.
> Run the two outputs of the duplexer to the rig as they are being
> done now.
> Or is there more to it than that?
> Bob AD5VJ
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