Steve,
Thank you much for this. The first thing I'll do is contact CushCraft to see
if they have any words or hardware appropriate to the twin anntennas of
theirs I have.
Good of you to write.
Jerry
----- Original Message -----
From: "Steve" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Monday, May 21, 2007 2:59 PM
Subject: Re: Stacked arrays on VHF & UHF
> Jerry,
>
> I have experienced with baying arrays, which is horizontally split, but
> not
> vertically stacking them. I can also tell you of a setup I had years ago.
>
> First, as far as the two antennas. You'll need a phasing kit which
> consists of
> a T-connector and two lengths of 75-ohm cable to match the two antennas as
> they
> will be fed in parallel. I don't remember the length of the phasing
> cables, but
> you can get them already mead up as part of a separation kit from
> Cushcraft.
>
> The other thing you need to consider is the phasing of your transmissions.
> It
> used to be that the birds were left-hand circular polarized, if I remember
> correctly. SSB is horizontal, and FM is vertical. Which mode will you
> use the
> most? If satellite, then you need to circularly polarize it if that is
> still
> necessary for the newer birds. My experience if from Oscar 13 days.
>
> A second consideration is that if you phase your two antennas, you will be
> narrowing the beam width. That will mean that you might need to track
> them more
> precisely.
>
> Some thirty years ago, a brilliant friend of mine, Wa8LMF, came up with
> the idea
> that I could put up a pair of 8-el HyGain two-meter beams and phase them
> either
> vertically, horizontally, or righthand or lefthand circular as my
> operating mode
> changed. The way we did this was to put one beam up oriented with the
> elements
> going from upper left to lower right. The lefthand beam on the horizontal
> boom
> had its elements going from upper right to lower left. The two feedlines
> entered the shack and fed a T connector to the rig. If I wanted to change
> the
> phasing, I inserted either a quarter wave in the left or right feedline
> for
> circular polarization if I recall, or a half-wave phasing line in one side
> to
> switch to horizontal polarization.
>
> I do know this much. If you worked FM and switched it to horizontal
> polarization, you had a considerable drop in signal strength. And, when
> talking
> with an FM station, running circular polarization seemed to reduce the
> amount of
> picket fencing.
>
> Steve, K8SP
> ----- Original Message -----
> From: "Jerry Neufeld" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Monday, May 21, 2007 2:21 PM
> Subject: Stacked arrays on VHF & UHF
>
>
> I have 2 CushCraft dual-band, 5-element yaggies for VHF & UHF that I'd
> like
> to use for satellite work. Does anyone have any experience with stacked
> arrays of this type? Any ideas where I might obtain accessible material on
> how to optimize stacked, dual-band antennas? Any suggestions on this would
> be much appreciated.
>
> Also, I have a MFJ antenna analyzer, the 269 to be specific. Although this
> analyzer provides for UHF measurements, it does not have a pick-off for RF
> which I need for my MCount morse-code frequency reader. Anyone have any
> ideas on how I might gain access to the RF output of the analyzer without
> significantly influencing readings, especially for UHF?
>
> Thanks to anyone who has advice on these matters.
>
> Jerry VE3QSO
>
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