CIRCUIT DESCRIPTION
300-VOLT LINE
To minimize variations and ripple in the line, a
silicon bridge rectifier circuit and chalk input
system are employed for the 300-volt B line.
210-VOLT LINE
Resistors are placed in series between the 300-volt
line and the 210-volt line for the purpose of
dropping the voltage.
150-VOLT LINE
I f the 150-volt line voltage drops due to a varia-
tion of load, the grid voltage on the triod side of
V
2
o i 6BM8 will also drop. This causes the plate
current to decrease, since the cathod voltage is
fixed.
When the plate current decreases, the voltage drop
across the
R201
470 Kft becomes less, while the
plate voltage tends to rise. Accordingly, the grid
bias on the pentode side of 6BM8 tends to de-
crease, thereby stabilizing the 150-volt output at
the operating point. This output voltage can be
varied by adjusting the V R i half-fixed resistor.
( - ) C LINE FOR BIAS
The half-wave current is supplied to the ( - ) C line
for the bias through a silicon diode.
12.6-VOLT LINE
To supply heater voltages, the power transformer
has two 12.6-volt secondary windings; that is, one
for the final S2001 x 2 line exclusively for the
transceiver and the other for other vacuum tubes.
Taking into consideration a possible voltage drop
at the power supply cord between the PS-510 and
the TS-510, the transformer is provided with two
13.5-volt windings.
63-VOLT LINE
A 6.3-volt winding is used for heating the 6BM8.
To prevent the breakage of the insulation between
the cathode heaters, this winding is applied with a
voltage o f + 150 V .
SPEAKER TERMINALS
The power supply jack incorporates speaker line
terminals. The on-off power switch is attached to
the transceiver. Part of the lead wire to the trans-
former primary winding is connected with the
power supply socket. This enables the operator to
turn on or off the machine from the transceiver
side.
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