[50mhz] 50 mhz 5 elem beam

Mon, 15 Sep 2003 13:01:31 -0600

Rich & Jon,

I started out with the CushCraft A50-5S, and it basically worked as advertised,
but the front-to-rear ratio of the stock antenna is pretty poor (only about 13
bd). I used K6STI's YO (Yagi Optimizer) both to redesign the antenna on its
original 12 ft boom, and again on a longer 17.5 ft boom (which is the antenna I
actually built). To rebuild the antenna on a 17.5-ft boom, all you need is a
6-ft length of 1.5" tubing (cheap, and shippable via UPS from Texas Towers if
you don't have a local source). Saw the original center boom section in half,
cut compression slots in both ends of the new center section, buy a couple
stainless steel hose clamps at the hardware store, and you're set. It's a really
cheap upgrade.

The longer antenna has a front-to-rear ratio of 29 dB, a sharper main lobe, and
about 1.5 dB more forward gain (though my main design criterion was better
front-to-rear). This antenna was assembled, raised, and characterized Saturday,
and it comes out extremely close to the computer model in terms of its
front-to-rear ratio and overall pattern. I'm extremely pleased with it.  :-)

You could certainly download the A50-5S manual and duplicate the dimensions
shown there (wasting a couple feet of your 14-ft boom), but you could also run a
simulation for a 14-ft boom and come up with a design that will perform a lot
better. Performance is relative, of course. It depends on what you want! Living
more or less halfway between California and the southeast US, I often get hit
with signals from both directions when 6M is open during the summer, and I need
a good front-to-rear ratio. So I optimized for that.

Let me know if you would like me to run a few 14-ft models for you. Would be
happy to do that. If you want your own copy of YO ($100 from K6STI), write to
him by snail-mail. He's good on QRZ.com.

73,
Bill / W5WVO

----- Original Message ----- 
From: "Jon Neher" <[email protected]>
To: "Hernbrode, Richard A (MED)" <[email protected]>
Cc: <[email protected]>
Sent: 15 September, 2003 10:44 AM
Subject: Re: [50mhz] 50 mhz 5 elem beam

> I used the dimensions for the Cushcraft 6 meter beams as a model.
> You can download the .pdf manuals for any of them from the
> Cushcraft website.
>
> GL,
>
> Jon
>
> On Mon, 15 Sep 2003, Hernbrode, Richard A (MED) wrote:
>
> > I HAD A DIAGRAM W/ MEASUREMENTS FOR A 5 ELEM 6 MTR BEAM.  HAVE MISPLACED
> > SAME AND NOW I HAVE ALL THE PARTS FOR SAME.... BUT NEED TO KNOW THE
> > MEASUREMENTS.......
> > IF ANYONE KNOWS OF A WEB SITE W/ 6 MTR BEAM BUILDING PLANS, PLEASE
> > FORWARD TO ME.
> > THANKS, 73'S
> > RICK
> >
> > RICK HERNBRODE           KB9WJH
> > NEOSHO, WI                                EN53 rh
> >
> > Moderator: Ray Brown, KB0STN
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