Hy-Gain AV-640, Инструкция по эксплуатации и сборке

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Introduction
Hy-Gain is proud to deliver the AV-640 Eight Band Vertical. Drawing on our
many years of Amateur Radio HF and VHF antenna design experience, we have
produced a well-engineered antenna capable of maximum efficiency, unmatched
performance, and superior construction.
Computer optimization of the AV-640 design yields the most efficient 3/8
wavelength electrical design with maximum gain and low angle of radiation for
long distance communication. No traps are used to achieve eight band
performance. The AV-640 is resonant on 6, 10, 12, 15 and 17 meters with
individual 3/8 wavelength radiators. The center radiator resonates on 20, 30 and
40 meters using parallel end loaded Teflon wire coils. Capacity hats on these
bands give wide 2:1 VSWR bandwidth and the antenna is kept to a height of 26
feet by the low inductance coils. There are no "tricks" or "mystery resonances"
used for impedance matching on any band.
No long-wire radials or counterpoise kits are necessary for operation of the AV-
640. The AV-640 is self contained for simple, convenient portable or fixed
operation.
Mechanical construction of the AV-640 is designed for extreme light weight and
high wind survival. Aircraft grade 6063-T832 aluminum and high strength
fiberglass are used for the entire radiator. The trap-free design presents a very
low wind surface area. Bulky tubing is not required to support unwieldy traps.
The broad 2:1 VSWR bandwidth on all bands lessens large frequency shifts
seen in other antennas when the antenna is wet or iced.
The AV-640 is covered by our Hy-Gain Warranty and supported by our customer
service team. We would like to thank you for purchasing this product from us and
ask that you let us know of any suggestion you may have. With proper assembly,
installation, and maintenance, your AV-640 will provide years of faithful service.
Theory of Operation
The AV-640 HF Multiband Vertical antenna consists of an end fed radiator that is
resonant in the 6, 10, 12, 15, 17, 20, 30 and 40 meter amateur frequency bands.
Resonances on each band are the result of impedance matching a 3/8
wavelength element with a broadband RF transformer. The characteristic
impedance at the base of the 3/8 wavelength radiator is in the order of a few
hundred ohms.
To match this impedance two tools are employed. First a counterpoise of 72"
spokes is mounted at the AV-640 base. The capacitance from this ground plane