A.H. Systems SAS-512-2 Log Periodic Antenna
OPERATING INSTRUCTIONS
Once the antenna is mounted to a mast or tripod, connect an N-type coaxial
cable from the antenna to a receiver or RF generator. The cable should be
matched to 50 ohms, relatively low loss and adequately shielded against
leakage such as RG-214/U or better. For certain applications where an
increased dynamic range is required, an optional preamplifier (PAM-0202) may
be used to increase the total system sensitivity.
The Log Periodic Antenna is in the horizontal polarization when the antenna
elements are parallel to the ground, and vertical polarization when the elements
are perpendicular to the ground.
To minimize impedance mismatch errors, it is recommended that high-quality
in-line attenuators be used to reduce reflections. Connect the attenuator at the
antenna end of the transmitting cable, or when receiving connect the attenuator
at the measuring instrument or preamplifier input.
Dress the cables straight back from the antenna connector at least 1 meter
before being dressed vertically down to the ground plane. Signal cables that
are dressed orthogonal to the antenna elements will have minimal coupling to
the antenna field, but the cable shields may carry external currents caused by
impedance imperfections. Also, portions of the cables that are not straight down
or straight back will couple to the antenna fields.
A.H. Systems inc. – May 2014
REV C
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