If you can find it, the Eighth edition of the ARRL Antenna book (1956)
has about 5 pages on the Vee. Seems to me that ARRL publishes a wire
antenna book but don't know if there is much on the Vee. Maybe someone
could look at their copy and comment.
Here's another way to measure the apex angle of an existing Vee. Stand
right under the apex with a GPS and mark that location. Now stand right
under one of the wires at the far end and measure the bearing to the
apex location. Do the same for the other wire. The difference in
bearings is the angle of the apex as projected on the ground. If the
Vee is horizontal, that's the apex angle. If not, it isn't and you will
have to do a bit of trig or draughting to find the actual angle.
Whether the error will make much actual difference is another issue.
The same problem exists with the photographic method unless the camera
was pointing along a line perpendicular to the plane of the Vee.
73 de Jim Smith VE7FO
Al Williams wrote:
>Not many (only 2) responded to the posting asking for Vee beam info sources.
>The best source I know of is the ARRL Antenna book (18th)
>and that has only one page! But I find it to be very confusing when trying
>to determine correlation of apex angle and wave angle (elevation?).
>
>Also, I often hear hams referring to ~100' wires as long wires when used at
>10m and 20m. While that may be technically accurate, I think that any vee
>beam recommendation should include length of the wires as it makes a huge
>difference for selecting the apex angle.
>
>I have had a Vee beam up for about 5 years. It has an apex angle of 50
>degrees (available trees at far end) and each leg is 520' long. The apex is
>at 95' and the wires catenary down to about 20'. (BTW, I was never sure of
>the apex angle which I tried to measure holding a protractor overhead while
>trying to to get as close to the center of tree without the branches
>obscuring the apex.. I am proud that it finally dawned on me to use a
>digital camera, print the result and extend the wire lines on the print to
>the hidden apex and then measure!)
>
>I have used EZNEC to make many plots of Vee beam while varying the apex
>angle, frequency, and leg length. I can't imagine trying to
>design one without modeling capability. Since my Vee beam is 4L at 40m and
>16L at 10m, I selected the trees which gave the 50 degree
>apex angle as the best fit.
>
>How well does it work? I really don't know. My Vee is aimed to the East
>coast which should be excellent for the Sweepstakes contest.
> However, the difference between a dipole at 70', a 320' dipole at 85' and
>an A4S beam at 72' and the Vee was not obvious and I wound
>up using the tribander most of the time during the recent Sweepstakes voice
>contest.
>
>hope this is of interest to some
>
>k7puc
>
>
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