[amsat-bb] Antenna separation on crossboom

[Greg D]

That's pretty much what I did, though with different antennas.  Also put
the AO-40 dish on the other side of the rotor from the 23cm helix, so it
went 70cm, 2.4gig, rotor, 23cm, 2m.   Put things as far away from each
other as you can, without running out of crossboom.

I was very concerned about having the 70cm beam (uplink) so close -
inches - to the 2.4 ghz dish (downlink), but it was fine.  Good input
filtering in the 2.4 ghz Khune preamp, I guess.  More recently, Mode L/v
on AO-92 seems ok too, with the 23cm antenna near the 2m, but I have a
lot less power on 23cm than I did with AO-40 on 70cm.

Greg  KO6TH


Bob Hammond wrote:
> I'm putting the following antennas on an 8-foot fiberglass crossboom:
>
> M2 2MCP8A, 143-148 MHz C{
> Gulf Alpha 70cm 8x8 CP
> WiMo Helix 23
>
> I'm not sure how to calculate the proper spacing on the crossboom.  I
> assume the 2m antenna should go on one end and the 70cm antenna on the
> opposite end.  Can I mount the 23cm helical antenna very near the rotator
> without harm since it has the solid reflector behind the helix?
>
> Bob
> W7OTJ
> (was WL7CQX)
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