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Re: Clarc yagis



I have used an 11 element version for my AO-40 uplink and it works great.
Tunes up very nicely, with low swr , unlike some other things I have tried.

I thought the drawing was a little confusing too, but it's actually very
easy.

The Driven element need to be 13 in long.  Bend the end around to make the
"J" and squish it out so the spacing is 3/8 inch.  The outside of the curved
part is where you put your ruler when you measure 13 inches.  Measure 6 1/2
inches on the short side and make a mark.  That is where you want to solder
the coaxial cable.  The short end of the "J" should continue for another 1/2
inch.  If you use 1/2 pine it comes out flush on the other side.  I would
guess fiberglass should also work, but if you extend a full inch for
mechanical strength, that will effect the tuning, I'm sure.  If I were you I
would save the fiberglass for another project and go to Lowes or Home Depot
and look for some straight pine 1/2 square.  Use a good outdoor wood primer,
the thick white stuff you would use to prime wooden window frames or garage
doors.  Then a nice coat of color...I used aluminum Rustoleum enamel and it
looks great!  Will probably have to replace the wood in a couple years.

Set it up on a tripod or stepladder and check the SWR.  It will probably be
off a little.  Then clip off TINY bits (1/16 in or less) from the long end
to pull the SWR down.  My final length for AO-40 uplink was right at 12 3/4
inches.  I used a linear 11 element version with a barefoot FT-847 and got
into the satellite fine.

Good luck!

Grant Zehr AA9LC
----- Original Message ----- 
From: "David Carr" <dc@dcarr.org>
To: <amsat-bb@AMSAT.Org>
Sent: Saturday, March 06, 2004 12:34 PM
Subject: [amsat-bb] Clarc yagis


> I just finished construction on a WA5VJB 6 element 435Mhz beam.  I have
> a question though about where to attach the coax.  I'm using a 1"
> fiberglass tube as the beam and the geometric midpoint of the driven
> element is currently in the middle (inside) of the hollow fiberglass
> tube.  Is it okay to solder the coax connections on the outside of the
> tube (.5" from the geometric midpoint)?  The pictures on the Clarc
> website (http://clarc.org/Articles/uhf.htm) are ambiguous.
>
> 73s
> David Carr
> KD5QGR
> ----
> Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
> Not an AMSAT member? Join now to support the amateur satellite program!
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>


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