Topband: Fwd: RE: VE3DO Antenna

[Bill Tippett]

---------- Forwarded message ----------
From: "Joe Subich, W4TV" <w4tv at subich.com>
To: "'Gary Nichols'" <kd9sv at comcast.net>, <Topband at contesting.com>
Date: Wed, 2 Jan 2008 22:23:49 -0500
Subject: RE: Topband: VE3DO Antenna

Gary,

My modeling shows The "DO Loop" to behave essentially the
same as the classic K9AY although the VE3DO lacks the high
angle back null of the K9AY.

At 1.825 MHz:    VE3DO      K9AY     Flag
Gain             -30.0     -25.7    -29.6    dBi
F/B                6.3      11.1     35.5    dB
RDF                7.1       7.5      7.8    dB
Beamwidth          165       173      155    degrees
TOA                 45        35       35    degrees

I've attached my VD3DO model to the direct e-mail but there
are no special techniques.

I see nothing to recommend the "DO Loop" and its need for two
vertical supports over the classic K9AY array with its single
support and the capability of four direction switching.  If I
were going to the effort of two vertical supports, I would be
more interested in a 15'x30' flag for its generally better rear
rejection (although the modeled benefits over the K9AY do not
compensate for the loss of easy "rotation").

73,

  ... Joe, W4TV