TM 11-5820-801-30
c. Power Divider PD1. The pump power from
adjustable over a 0 to 6V range. Manually operated
switches (54 for the first stage and 55 for the second
crossguide coupler DC1 is split into two channels by
stage) permit the operator to connect either bias voltage
means of a waveguide power divider PD1. The divider
line to the midpoint of the divider (instead of the wiper
has an insertion loss of about 0.1 dB.
d. Isolators AT1 and AT2. Each pump channel
arm) thereby providing a 6-V bias. This effectively "turns
off" (bypasses) the amplifier stage by biasing it out of
(output channels of PD1) has an isolator (insertion loss
operating frequency range and at the same time
0.15 dB) to provide adequate channel isolation (20 dB)
provides minimum insertion loss for that stage. The
This helps prevent "crosstalk" between the two amplifier
correct bias voltage for each amplifier stage is
stages.
determined during a gain-bandwidth alignment (para 3-
e. Variable Attenuators AT3 and AT4. The gain,
7).
and to some extent the bandwidth, of amplifier stages
d. DC Amplifier Voltage. DC amplifiers in 2A1
2A3 and 2A2 is affected by the pump power level at the
(2A1 Power Monitor, fig. 2-1) and Unit 1 (1A1
paramp varactor diode. To adjust the power level in
Temperature Monitor, fig. 2-2) contain an IC operational
each amplifier stage, a variable waveguide attenuator
amplifier (U1) (fig. 2-9, 2-14) that requires + 12V and - 12
(AT3, AT4) is used in each pump powerline. A lossy
V for operation. These voltages are obtained directly
card (100 ohms per square inch) is inserted into the
from A10 and A11, the + 12 volt and - 12 volt regulators,
variable waveguide by a screw adjustment and is set
respectively. The two regulators are identical. In this
during gain-band-width alignment procedures (para 3-7).
power supply the positive end of A11 is connected to the
Attenuation is variable from 0 dB to more than 20 dB,
negative end of A10 thereby providing a common 12 V
insertion loss is about 0.1 dB. Attenuation variation is
return line. A trimpot on each 12-V regulator permits
not directly translated into gain variation. Operating
some adjustment of the output voltage. The trimpot is
temperature of AT3 and AT4 is maintained at about
preset before installation to provide a 12 0 12V output.
135F by controlled heaters in a heat sink adjacent to the
attenuators (para 2-11).
2-8. Monitors in Signal Amplification Circuits
a. VOLTAGE Meter 1M4.
By means of a
2-7. Klystron Power Supply 1PS1
VOLTAGE selection switch (1S2) on the front panel of
a. General.
Unit 1 the operator can select 1PS1 output voltages to be
Klystron Power Supply 1PS1
displayed on VOLTAGE meter 1M4 (fig. 2-1) VOLTAGE
contains four regulated power supplies receiving their
meter 1M4 provides a direct measurement of the output
input power through a single transformer (T1) that
of 1PS1A10 and 1PS1A11, the 12 V regulators. The
accepts the three-phase 120 12 V, 55 8 Hz primary
negative voltage from A1 is reversed at the meter
power. Four three-phase outputs of T1 are connected to
terminals so that a positive deflection is obtained Beam
rectifier board A7, which supplies power to a -1000 V
voltage (-1000 V from A9) is sampled at 0.01 amplitude
regulator (A9) for the klystron oscillator beam voltage, to
(by means of a voltage divider in Unit 1) so that
a 6.3-V regulator (A1) for the klystron oscillator filament
VOLTAGE meter 1M4 indicates 10 0.5 when the beam
voltage, to a + 12 V regulator (A10) for the varactor bias
voltage is - 1000 50 V The output of A1, the 6.3-V
voltage and the dc amplifiers, and to a - 12 V regulator
regulator, is not monitored.
(A11) for the dc amplifiers. Each 12-V regulator is
b. PUMP Meter 1M5. The output of (Power
separated from rectifier board A7 by a preregulator.
b. Klystron Power. The outputs of - 1000 V
displayed on 1M5, PUMP meter, by use of PUMP
regulator A9 and 6.3-V regulator A1 are supplied directly
selection switch 1S3 (fig. 2-1). Because the output
to klystron oscillator 2A1V1. The beam voltage (- 1000
voltage of crystal detectors (2A1CR1, fig. 2-1) varies
V) is variable 50 V via a trimpot on A9. The correct
over a wide range a meter adjustment (PUMP POWER
beam voltage is that which provides the most pump
METER ADJ R7 on rear panel of Unit 1, fig. 3-3) is
power and is originally set by the manufacturer during
provided to align PUMP meter 1M5 to indicate in the
initial alignment procedures. The high side output line of
green area of the scale (4 to 6) when pump power (para
A1 is connected to the high side (- 1000 V) output line of
A9. Thus the filament voltage is floating on top of the
operate with the 2A1 module with which it is shipped
beam voltage and from a chassis ground point of view,
Interchanging Unit 1's or 2A1 modules may necessitate
the filament voltage is - 1000 V on the high side of A1
realignment of PUMP meter 1M5. Replacement of piece
output and - 1006 V on the low side of A1 output.
c. Paramp Varactor Bias Voltage. Bias voltages
parts or subassemblies in either the 2A1 portion or Unit 1
portion of the pump power monitoring (and generation)
circuit may also necessitate realignment.
derived from the + 12 V regulator (A 10) output. The
c. PARAMP ELAPSED) TIME Meter IM3.
bias voltage for each amplifier stage is passed through a
PARAMP ELAPSED TIME meter 1M3 is a time totalizing
voltage divider (1R5, 1E1R8 for first stage; 1R6, 1E1R9
meter operating on 120 12 V, 55 8 Hz. The meter
for second stage) network in Unit 1 having a trimpot 1R5,
indi-
1R6 as half the divider. The bias voltage is taken off the
wiper arm of the trimpot and is therefore
2-4
