TM 11-5895-1090-34/TO 31 R2-2TSC-152
resettable by means of front panel FAULT RESET
from shf combiner assembly Al (para 2-6) is passed
switch S4. Twt cathode current is monitored by front
through isolator HY1 to a 10-db directional coupler
panel STATUS MONITOR meter M2 when the STATUS
(DC1), which samples the shf input signal. Diode
MONITOR switch is placed in IPA MA position.
detector CR1 detects this signal and provides an output
b. Amplifier assembly A3 may contain an fet
proportional to the level of the shf input. The main
amplifier in place of the twt amplifier. The fet amplifier
signal path output of directional coupler DC1 is passed
performs the same functions and at the same level as
through gain set attenuator AT1, output level adjust
the twt amplifier and is directly interchangeable with it.
attenuator AT2, and the fixed attenuator AT3 to
Transient Suppressor Assembly A4
AT1 is manually adjusted to set the desired gain of the
unit. Output level attenuator AT2 is adjustable by
means of the OUTPUT LEVEL control and allows
varying the output power of the amplifier-mixer. AT3
miscellaneous components required by the amplifier-
reduces range required for AT1.
mixer. These components are described below.
Amplifier Assembly A3
a. Resistor R1 is a voltage dropping resistor
connected in series with the positive terminal of
STATUS MONITOR meter M3.
a. Twt amplifier assembly A3 consists of a
b. Resistor R2 is a current limiting resistor
fixed broadband amplifier (approximately 40 db) and its
used to drop twt cathode current applied to STATUS
power supply packaged as a unit. The twt amplifier
MONITOR meter M3 via the STATUS MONITOR
provides amplification of the shf signal for application to
c. Potentiometer R3 allows adjusting a preset
supply has its own built-in fault protection which trips
threshold used by a comparator circuit on rf low power
under conditions of excessive beam current and/or
alarm assembly A5.
excessive twt heat sink temperature. This fault circuit is