Suggestions, 3 ele 40M Beams?

[Frank Donovan]

If any of you are interested in the design details of my homebrew
3 element 40M Yagis, I'll be pleased to share them.  They are big,
heavy and require a prop-pitch or an equivalent large rotator.  They
designed to withstand 100+ MPH winds or  several inches of radial ice with
less wind.  All of the materials are readily available, nothing fancy.
Construction and installation require substantial labor but no special
skills.  My 40M beams have been installed for 25 years, and survived all
but the 120 MPH wind shear event in 1994.  Even in that case the 3 element
40M Yagis were repaired and back in operation after only brief repairs.

Serious inquiries only please...

73
Frank
W3LPL
donovanf@sgate.com


 ---------- Forwarded message ----------
Date: Wed, 11 Dec 1996 10:22:58 -0500
From: K7LXC@aol.com
To: rickdav@pcix.com
Cc: cq-contest@tgv.com
Subject: Re: Suggestions, 3 ele 40M Beams?

In a message dated 96-12-11 06:57:26 EST, you write:

>I am looking for suggestions for a commercailly available 3 element 40 Meter
>beam. Has anyone out there used the Hygain ? Is it any good ? Any comments
or
>suggestions will be appreciated.

Hi, Rick --

    Sounds like you're looking at linear loaded antennas.  They (KLM, M2,
Force 12, Hy-Gain) all have their limitations.  The Force 12 version is the
only one that has been designed in the era of computer modeling (sorry to
Mike, K6MYC, if this isn't true).  And Tom Schiller, N6BT, being a clever
antenna designer, I would suspect that its performance might have a slight
edge on the other antennas.

    The Hy-Gain hasn't captured the hearts or pocketbooks of competitve
amateurs so that sort of speaks for itself.  

    I've owned the 2L and 4L KLM's and am happy to be rid of them.  They are
mechanically fragile and I never did feel that they worked as impressively as
they looked.

   I'm now using a Cushcraft 402CD and am much happier with it than the 4L
KLM.  It is more reliable and works almost as well.

    If you want smash on 40M and you don't want to go to the cost and hassle
of a full-sized 40M yagi, here's a couple of scenarios that I would suggest.

1)  Design and build a full-sized 2L beam.  Pretty efficient and the
mechanical construction is reasonable.  Call Texas Towers for raw aluminum.

2)  Add a director to the 402CD.  You'll need a new boom but again the
mechanical problems are pretty straightforward.

3.  Put up a 2-stack of 402CDs.  In the final analysis, you get around the
same amount of gain that you'd have with a full-sized 3L for a fraction of
the cost.  You can even turn them with Ham IV's.  Plus your overall takeoff
angle will be lower due to the stacking effect. 

    BTW, a better place to post this questions would be TowerTalk - the tower
and HF antenna reflector.  Send a message to towertalk-request@akorn.net with
subscribe in the message and you'll be all set.  See you there. 

73,  Steve  K7LXC

    TOWER TECH -- professional tower supplies and services for amateurs


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