TM 11-6625-1633-45
capacitor C35, choke L1B, and capacitor C36.. The
The operation of power supply is similar to the reflector
resulting dc voltage appears at the plate of series regu-
power supply (para 2-7) except that time delay relay K1
lator tube A3V5. The grid of regulator tube A3V5 is
allows the klystron a 60-second warmup period before
connected to the plate (pin 1) of voltage control tube
operation of power relay K2 energizes the beam power
A3V6. The two triode sections of voltage control tube
supply. KLYSTRON indicator lamp DS2 lights (yellow)
A3V6 are connected in cascade and operate as a two-
when the -325-volt beam power supply is operating.
stage dc amplifier. The cathodes (pins 3 and 8) of con-
trol tube A3V6 are tied to the cathodes of voltage refer-
2-9. Analysis of Modulator and Bridge
ence tubes A3V7 and A3V8 respectively. The grid (pin
Power Supply
7) of control tube A3V6 is connected to the wiper arm of
REFL-650 potentiometer A3R8. Since the cathodes of
control tube A3V6 are maintained at a fixed voltage by
a. The modulator power supply furnishes regulated
reference tubes A3V7 and A3V8, voltage variations in
dc plate voltage to all tubes in the modulator-oscillator,
the power supply output will appear at pin 7 of A3V6.
the modulation amplifier, and the deviation meter cir-
These changes are amplified by A3V6 and are applied to
the grid of regulator tube A3V5. The voltage drop across
CR16 through CR19 is filtered by capacitors C42 and
regulator tube A3V5 changes and restores the power
C43, and choke 12 and is applied to series regulator tube
supply to the preset voltage.
V4 (of which only one section is used). Dual triode am-
plifier A2V2 functions as a control amplifier and oper-
b. The circuit also provides -650 volts at the negative
ates from the reference voltages furnished by voltage
terminal of supply resistor A3R4. This voltage is applied
regulator tubes A2V3 and A2V4. The operation of the
through pin C of jack A3J2 and pin A of jack A4J3 to
modulator power supply is essentially the same as the
the reflector tracking circuit. Resistor A3R4 is in series
operation of the reflector power supply (para 2-7). Re-
with REFL -650 potentiometer A3R8 and resistor A3R9,
sistors A2R7, A2R9, and 250V voltage adjust potenti-
which is referenced to the -325-volt beam power supply
ometer-A2R8 comprise a bleeder circuit across the out-
at the junction of GRID BIAS potentiometer A3R11 and
put.
capacitor A3C1. In parallel with these resistors is a
bleeder network formed by series resistors A3R5 and
b. The function of the bridge power supply is to fur-
A3R6. When MODULATION selector switch S2 is in
nish a constant negative 108-volt potential to energize
the OFF position, the voltage at the junction of resistors
the power monitor bridge circuit (para 2-8). Full-wave
A3R5 and A3R6 is connected through pin B of jack
bridge rectifier diodes CR20 through CR23, provide a
A3J2 and the switch to the grid of the klystron. This
full-wave rectified output to pentode series regulator
voltage is approximately 20 volts more negative than the
tube V5. Capacitor C44 acts as a filter. Dual triode am-
beam voltage, and therefore cuts off the klystron.
plifier A2Vl functions as a control amplifier and oper-
ates from the reference voltage furnished by voltage
2-8. Analysis of Beam Power Supply
regulator tube A2V5. The operational difference be-
tween the modulator and bridge power supply is as fol-
lows: The bridge power supply reference voltage for
a. The beam power supply is a regulated power sup-
amplifier tube A2V1 is obtained by the voltage divider
ply that furnishes the klystron beam voltage. Except
network consisting of regulator tube A2V5 and resistor
when MODULATION selector switch S2 (fig. 2-7) is at
A2R12. The voltage divider is connected between the
OFF, the klystron bias is tapped from the beam power
+250 volt regulated modulator power supply and the -
supply and maintains the grid positive with respect to
108 volt bridge power supply output voltage. The grid
the cathode. This permits the klystron to oscillate. The
of amplifier tube A2V1 is connected to the junction of
power supply uses a full-wave bridge diode rectifier
regulator tube A2V5 and resistor A2R12. The grid volt-
comprised of diodes CR1 through CR4 connected to a
age is therefore the difference between the constant volt-
ripple filter through 60-second delay relay K1. Power
age potential across regulator tube A2V5 and the 108-
pentode A3V1 is used as a series regulator tube. Dual
volt output of the bridge power supply. Any voltage
triode A3V2 functions as a control tube, and regulator
change in the bridge power supply output causes ampli-
tubes A3V3 and A3V4 act as voltage reference tubes.
fier A2V1 to apply a control signal to series regulator
tube V5 to prevent the output voltage from changing.
2-5
