Re: [amsat-bb] Antenna array phasing questions

["Michael McCarty" <mmccarty@xxxxxxxxxx>]

> Second, the antennas are fed with a gamma match/coax balun feeds 
> and have 50 ohm inputs.  I have a four port power divider with 
> 50 ohm inputs.  Assuming that matching is taken care of and that
> I would need each antenna  coax run to be the same length for
> proper power division are there any specific coax lengths to
> avoid?  Perhaps multiples of 1/2 wave resonance?
> 
> Lastly, the gamma matches on each of the four antennas are built
> identical to each other.  If the bottom two antennas in the array
> are flipped over so the feedpoints face the center of the array do
> I need to change which side of the gamma match is tied to the
> center pin of the coax connector?  What is the proper phasing 
> between the four antennas, perhaps keeping the hot side of
> the gamma match to the outside position and the grounded side to
> the inside of the array on each antenna?  Is there a specific phasing
> relationship to follow or is symmetry the important thing?

Let me correct myself here.  As I look through my reference books
trying to find the answers to these questions I realize that the match
is actually what is referred to as a "T" match.  It is a T match with 
a UT-141 coax balun just as the plans in the handbook show.

-Mac, KB8YHV
Alamogordo, NM 

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