[Moon-Net] 2M antenna matching Data

Ray Rector wa4njp at bellsouth.net
Mon Nov 7 22:13:32 CET 2016


Well said Terry, I think to many fancy numbers with a  realistically small difference is clouding the main focus...I see a lot of this here with new analyzers that spit out all this real information, and some of it a bit useless, in the real world..But do double check, measure twice, cut once and get it on the air..   Curt  and Steve  GL with the projectsRay

      From: Terry Price <w8zn54 at verizon.net>
 To: moon-net at mailman.pe1itr.com 
 Sent: Monday, November 7, 2016 3:53 PM
 Subject: Re: [Moon-Net] 2M antenna matching Data
   
I think maybe you are over-thinking this. If the electrical length of the
phasing lines that connect from the antennas to the power divider are the
same (as measured on a network analyzer) and the distance from the center
pin of the N connector to the Tee arm on the antenna is the same, the phase
can't be off - as long as you have both driven Tee arms on the same side.

If the antennas are the original design by Steve (K1FO) and sold by Tom
Rutland using 1/2" driven elements and 3/8" Tee arms, the shorting bars will
be almost at the very ends of the Tee arms. Even if one antenna has the
shorting bars 2 or 3 inches from the other antenna, I'm not sure what if any
difference it would make except in the match.

After making a LOT of phasing lines in the last three years, I will say
there is a difference in coax. Even the beloved Times LMR-400. In two 20
foot pieces I've seen an inch difference to make the phase difference less
than 1 degree @ 2m. This is from contiguous cuts on the same reel. I've
actually found the Advanced Digital cable that the RF Connection sells is as
repeatable as LMR-400 if not more so.



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