Western Electric 407A-4, Instruction Manual

Page: 82 / 136

DlOA - 11Test Meter11 - Connects the test meter M2A to
the various cir cuits in this unit.
Dl3A - Link switch for adding capacity to neutralizing
condenser Cl5A. Leave open.
Dl5A
)
- Link switches to connect thermocouple TC2A in
Dl6A
)
circuit. Leave thermocouple out of circuit ex­
cept when tuning.
Dl7A - Link Switch - Close to position 3 to neutralize
3rd RF. amplifier. Close to position
4
to tune
modulating and power amplifier. Close to posi­
tion 2 to adjust feedback and monitor recti­
fiers. Leave in position 2.
Amplifier
DlC - "Door Release" - Momentary push button to oper­
ate electric door latches. Energizes th e
latches only if both rectifier switches DlG and
DlH have been operated to ground the high volt-
age.
D2C
to - Gate Switches
DSC
D6C - 50 - 5-kw plate Supply Transfer Switch
D30C - Link Switch - Put in D30. 2C position to neu­
tralize this stage. To operate leave in D30. 1 C.
D31. 1 C
)
- Link Switch - Close to tune series circuit L31 -
D31 . 2C
)
C32C. Leave i n open position.
KlC - "Filament Voltageu - Switches M3C to filament
of either tube. Leave in either position.
Power-Amplifier
DlD
)
- Gate Switches - deenergizes bias and high volt­
DlE
)
age rectifiers.
D2D
)
- Door Release - Momentary push button to operate
D2E
)
electric door latches. Energizes the latches
75