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Re: A question about 75 Ohm connectors



I think I was unclear: One element would immediately at the feedline
tee, the other element would be 1/4 wavelength of coax away from that
point.


73, doug

   Date: Wed, 12 Feb 2003 17:15:00 -0600
   From: Jon Ogden <na9d-2@speakeasy.net>

   Actually, Doug, I don't think that's what you want.  If you do that, the
   elements will be in phase.  You want them 90 degrees out of phase which will
   not be the case with what you explain below.

   For 90 degrees phase shift, you need the 75 Ohm cable, but I am not sure if
   the length of 1/4 wave or half wave.  I was just reading this
   somewhere....yes, in the satellite experimenters handbook.  I can look it up
   later tonight when I get home if someone doesn't beat me to it!

   73,

   Jon
   NA9D


   on 2/12/03 1:33 PM, Doug Faunt N6TQS +1-510-655-8604 at faunt@panix.com
   wrote:

   > Hi all,
   > Since we're talking about phasing lines, I have a question:
   > 
   > I've ordered one of the cross-Yagi's from Arrow, and it's the type
   > with little offset between corresponding elements.
   > The way to feed this seems to be to have a 1/4wave phasing line
   > between the two driven elements.  If I'm correct, the easiestway to
   > do this is to have two mathcing elemnts set for 100 ohm, use a piece
   > of RG62 93 ohm cable to connect one element to a T on the other
   > element, which is fed by 50 ohm cable.  Since I have no analyser for
   > 70cm, it looks as if I could put a 100 ohm resistor on the T, and
   > adjust the matching for 1:1 SWR.  I'd then do that to the other
   > matching element, and I'd have the right thing.
   > 
   > Have I got it right?
   > 
   > Excuse the spelling, my mail system is acting up.

   -------------------------------------
   Jon Ogden
   NA9D (ex: KE9NA)

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