[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Antenna array phasing questions



I've just completed building four FO-22 yagis for 432 MHz as per
the plans in the ARRL handbook, but have some questions about
mounting them in an array.

First off, for E and H plane stacking distances, which is vertical and
which is horizontal?

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?

-Mac, KB8YHV
Alamogordo, NM   



----
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org



AMSAT Top AMSAT Home