Hy-Gain LP-1009A, Instruction Manual

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VSWR Curves
These VSWR curves are typical for the antenna
mounted 70 - 80 feet above the ground and fed
with 100 feet of RG-213/U cable. Similar curves
can be expected for this antenna mounted
between 50 and 100 feet above ground. DO NOT
TRY TO TUNE THIS ANTENNA FOR LOW
V S W R A T
GROUND LEVEL. Higher VSWR
can be expected if mounted at less than 40 feet or
within 20 feet of a large roof or metallic structure.
Guy wires within 10 feet of this antenna should
be broken into non-resonant lengths (less than 12
foot lengths) and insulated from the tower. Other
antennas which are resonant somewhere in the 3 -
40 MHz range should be kept at least 10 feet
above or below this antenna. Antennas which are
resonant above 40 MHz can be mounted as close
as 3 feet from this antenna. The measured VSWR
may also be affected by strong local broadcast
signals.
Extreme care must be used if you use an air-
dielectric coaxial cable such as Belden 9913.
Water intrusion can easily raise the VSWR and
loss.
Hy-Gain recommends the Bird Model 43
directional watt meter to measure reflected power
and
V S W R .
This meter with the 250 watt 2 -30
MHz element will give the most accurate
information.
VSWR Curves