[VHFcontesting] 432 Yagi Design Help

David Vondrasek n5ito at arrl.net
Mon Oct 27 18:03:47 EST 2003

I have an old 432 18 ele Sat cross beam ( 9 ele V - 9 ele H ) with a shot
relay/phasing box. With an 80 element DX-432 array going up very soon and I
don't use Satellites I really had no use for it. Then I got  bored and was
thinking of extending the boom and making on hell of a long boom yagi out
of it , maybe 2 and stacking them for EME or 432 tropo work and give me an
antenna to compare to the 80 ele array.. I have lots of tubing that is the
same size as the current boom so extending isn't an issue. I'm really weak
on how to feed such an antenna,. 

Currently it has a  Folded di-poles as the driven elements such as the
Cushcraft  738XB does seen here


But the elements are mounted through the center of the boom much like the
M2 Yagis are.

I have *lots* of Cushcraft elements ( 96 to be exact) with the M type
bracket for the elements they use for Yagis and was thinking of using this
feed set up and building a LONG BOOM yagi with about ohhhh lets say  28-32
elements .

The Cushcraft  729B boomer


uses a  T-Match as the driven element. . Is there a reason for switching
from a T-Match to a Folded di-pole feed on these antennas ?

My plans are to use one of the folded di-pole directors and use the M-type
mounting brackets on top of the boom and build something in the area of
28-32 ele yagi.  This should give me about 17 db I guess..If I can feed it
this way.  If if all goes well build another out of the other driven
element and stack them for a total of 56-64 ele mounted at 50 feet. Since I
only have 12 watts on 432 I need all the gain I can get. Antennas are
cheaper for me as I have lots of parts. And amps cost cash.. I'm looking at
getting in the area of 20-22 db if I can for the  432 playground

Comments ?

http://david.davidv.net  <-- My shack

David L. Vondrasek
N5ITO Amateur Radio Call

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