A.H. Systems Model SAS-551 Passive Monopole Antenna
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A.H. Systems inc.
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GENERAL USE INSTRUCTIONS
The SAS-551 monopole antenna is a passive antenna designed to transmit
broadband electric fields. When used with the SAS-550-1B active monopole,
these antennas are the ideal solution for shielding effectiveness testing. This
antenna may also be used as a passive receive antenna for testing in areas
with high fields.
Each antenna is individually calibrated per ANSI C63.5 (ECSM) and comes with
a calibration certificate references the NIST traceable test equipment.
The calibration tables shown provide a listing of the frequency of operation and
its antenna factor in dB/m. The field strength is the receiver voltage in dB
V
plus the antenna factor (refer to the antenna factor calibration) plus any cable
loss. When making a measurement, mount the antenna on an appropriate mast
or tripod.
Caution:
It is recommended to load the monopole input with 50 ohms or use a power
resistor (connected in parallel with the antenna) if the signal generator or power
amplifier used to drive the antenna requires a 50 ohm match. This requirement
is typical for antennas with short radiators (radiator length of λ/10 or less) and
that operate below 30 MHz.
The SAS-551 antenna by itself does not represent a 50-ohm load to the
signal source.
OPTIONAL EQUIPMENT
The following is a recommend accessory list for the SAS-551 Passive Monopole
Antenna:
ECF-10
The ECF-10 is an equivalent capacitance fixture constructed per IEEE 291 and
ARP 958. This is an indispensable tool used for gain adjustment and calibration
of the active monopole antennas. The ECF-10 is used as a signal substitution
source when calibrating the active monopole antennas. Refer to the calibration
procedures below.
SAC-210
