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6.1.1 F
D
UNCTIONAL
The Discrete Interface is connected to the Alarm/Indicate Board and continuously (in the normal
condition) monitors the status of the SSPA:
If:
• the power amplifier is ON
• there are no problems in the power amplifier
• the power amplifier is not muted,
the
FAULT
relay is energized.
If:
• one or more GaAs FET's failed, or
• the power amplifier is muted,
a Summary Alarm signal will be internally generated and consequently detected by the
Alarm/Indicate Board; by receiving this signal, the
close contact being connected to its common terminal. This will indicate a FAULT condition on
the customer interface.
The Alarm/Indicate board receives an output VSWR signal from the reflected power sensor. The
power amplifier will be muted when the input voltage is above the threshold level (with 1 sec.
delay). Also, the power amplifier will declare the FAULT condition because it will be in a
shutdown state.
Power-up returns unit to active condition if the power amplifier is in the normal condition. The
threshold level is set for VSWR of 3:1, max. (6 dB back off from rated power).
WARNING: Prolonged operation without a load at the output may cause severe bodily harm,
loss of sight, even death. Do not operate any power amplifier if the RF output is not connected
to a load.
6.2 RF O
M
UTPUT
ONITOR
This RF interface is located at (J4) connector, of SSPA. It is typically used for independent
monitoring of SSPA output power levels through the use of an external power meter. To
determine the true output power in dBm, add the value measured at the RF Output Monitor Port
(J4) to the calibrated coupling factor corresponding to the specific frequency. A table of coupling
factor versus frequency can be found in the Test Data Sheet provided with each SSPA.
ESCRIPTION
P
ORT
AWSA-K50-CHE
FAULT
relay is de-energized, its normal
Page 21
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