> From: "Jorge Diez - CX6VM"
> Subject: RE: Topband: Vee Beams
>
> I forgot to tell that the idea is a SLOPING Vee Beam, apex at 110''
> and the 2 ends at ground level, terminated in a 450 ohms resistors
> connected to ground rods.
Jorge, I tried a similar approach in the late 70's and early 80's with a 300
foot tower support but the interaction of the feedline, the tower, made any
significant improvement uncertain. The use of 312 ohm non inductive 100
watt resistor at the end of the wire did however appear to quiet the antenna
down a bit from local noise. Since the sloping wire were less than 2
wavelengths I doubt if there was any gain. I presumed the antenna to be
aperiodic similar to the B&W and having broadband characteristics. It seemed
to hear well but the TX in the favored direction was no better than a
sloping dipole in general comparison made the same nights but never true A/B
tests.( hot switching was not possible since the same tower supported each
at different times by dropping the antennas on a long rope halyard and
running up the other.).
When the inverted Delta Loop was studied and recommended by DX-ers, Voilla,
I found something that worked well and was ideal to hang from (even if at a
45 degree slope) a tall tower and that was the full wave, corner fed, Delta
Loop. It provided great quiet RX performance, as well as some low angle
vertical radiation along with some high angle stuff. But it was a solution
to many dilemmas of feedline problems, interaction, matching, and the idea
of dissipation of power in the grounding resistors did not appeal to me. It
was a single band affair but the match could be close at the corner with 50
to 75 ohm coax. Having 160 feet of this antenna wire running a few feet
above the ground was always difficult to reconcile yet today I have (8) 600
foot wires running a few feet above the ground (called Beverages) that makes
the difference between hearing or not.
Judging from the plots published on the inverted Vee's compared to the Delta
loops it would appear that the full wave Delta loop , even sloping 45
degrees from a tower and corner fed, might be a better choice than and
provide some benefits such as better noise immunity that the models can't
predict.
Yes I have a box of expensive 100 watt non inductive 312 ohm resistors not
used in 25 years. I guess six in parallel would make a nice air cooled 52
ohm dummy load.
Herb Schoenbohm, KV4FZ
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