[v31xe@dzn.com: Vee-beams]

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From: William R Colbert (af852@rgfn.epcc.Edu)
Date: Sat Sep 06 1997 - 22:43:40 EDT


    ================= Begin forwarded message =================

    From: v31xe@dzn.com ("William R. Colbert")
    To: af852@rgfn.epcc.Edu
    Subject: Vee-beams
    Date: Sat, 06 Sep

    
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    --
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    "Politicians are like nappies. Both should be
    changed regularly -- and for the same reason"
    ---------------------
    Ray Colbert, W5XE,
    OOTC 3618, SOWP 1064M
    (also af852@rgfn.epcc.edu)
    El Paso, Texas
    
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    Thanks for posting the info on the vee beams. I am sure some of
    the gang will find it helpful. Before retirement last year, I
    had under my charge a rosette of 5 sloping vee beams designed after
    the article published in a mid-1950s QST by Col. LLoyd Colvin, W6KG.
    These were 505 feet on a leg with an apex angle of approximately 28-
    30 degrees. This causes some loss at some freqs but the gain figures
    seemed to be on the order of 3db at the lowest measured (1.9) and
    approaching 14 db in the upper 24 to 25 Mhz range. The far support poles
    (high grade wood utility type) were set on an arc of 250 ft apart. When
    compared to the installed 17 element HF 6. - 30 Mhz RLPA's, the
    performance of the v-beams far exceeded that of the log periodics at
    65 and 85 feet.
    For a wideband antenna that is relatively inexpensive, that is one
    way to go. The ones I used were sloping from 65 feet down to a level of
    20 feet (because they were planning to build underneath another 1 story
    building) but would have been better if the termination ends were nearer
    to 10 feet. The termination should be approximately 800 ohms, 400 ohm
    to ground on each leg. Grounds for the antenna, where the terminations
    were attached were formed by three ground wires, #2 copper on the poles,
    two going to ground rods on each side of the pole, and the 3rd to the
    ground plate on the bottom of the poles. You can feed it with open feeders,
    window line or coaxial cable thru a 16:1 balun.
    There is some excellent information regarding Vee beams in the
    Ed Noll, W3FQJ, book 73 dipole and longwire antennas. Comes with charts
    and gain figures vs # of 1/4 or 1/2 wl per leg, plus desired apex angle
    for a given length.
    
    
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--
Ray Colbert, W5XE
OOTC 3618, SOWP 1064M
El Paso, Tx (Far West Texas)
(also: v31xe@dzn.com)


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