TM 11-5895-846-14
3-14.
Receive Field Alinement.
For field alinement of the receive group the following test
equipment and cables are required:
Limiter, SM-A-934943
Cable Assembly, SM-C-935488-1
6 dB Attenuator, SM-A-937237-3
14 dB Attenuator, SM-A-937237-1
RF Power Meter, HP-436A with HP-848A Power
Sensor and HP-8481A Power Sensor
a.
LNA Low Noise Gain/Slope Adjustment
NOTE
The LNA low noise gain/slope is
adjusted using signal sources within
the terminal in conjunction with
precision attenuators and a low level
SHF hard limiter as shown in figure 3-
18. A signal at the local receiver
frequency is obtained from the SHF
local oscillator output (A1A1J2) of the
synthesizer
in
the
upconverter drawer. The output level
of signal is between the limits of + 6
and + 12 dBm. The signal is passed
through the SHF hard limiter and
attenuators to provide a - 66 dBm
signal at the low noise amplifier (LNA
1 or LNA 2) test port of the waveguide
switch on the antenna mounted
electronic subassembly and at the
LNA input.
3-33
