Display/Monitor Interface (PC3J1)
Jack – Pin #
Function
2
6
19
J10 – 20
SWEEP LED: This output controls the operation of the front panel SWEEP
MODE LED PC3DS4. With the OPERATE/SWEEP switch in the SWEEP (low)
position, U3C supplies a low to R23, J10-20, PC3J1-20 and transistor PC3Q4
which is forward biased to turn on PC3DS4. Placing switch S1 in the OPERATE
position will generate a high causing the SWEEP MODE indicator to go out.
J10 – 21
LEVEL ADJ OUT: Assuming the outputs of AND gates U1A/U1B/U1D/U2C/U2B/
U2D/U2A are high, amplifier U8A provides a reference of approximately 14V at
this output which is fed to the front panel LEVEL ADJUST potentiometer
PC3R16. This pot facilitates manual adjustment of IF/Converter variable attenu-
ator PC1CR7/CR8 and, therefore, manual control of the Exciter’s/transmitter’s
output power. If one of the above mentioned AND gates shifts low due to a fault
signal or command from:
J8-6
IF STATUS
S1
OPERATE/SWEEP
J6-3
2W AMPL STATUS
J2-8
LOCK STATUS
J9-1
REFL PWR
J5-1
REMOTE OP/STBY
J4-5
VIDEO SENSE
J10-7
OPERATE/STANDBY
then a low will emanate from U8A and pass through J10-21, PC3J1-21, LEVEL
ADJUST PC3R16, PC3J1-23, J10-23, J8-7, PC1J6-7 and PC1U9-5, increasing
the IF attenuation of PIN diodes PC1CR7/CR8 and significantly reducing the
output power of the Exciter/transmitter effectively placing the unit in standby.
J10 – 22
SYNTH LOCK LED: This output controls the activation and deactivation of the
front panel SYNTHESIZER LOCK light PC3DS2. The voltage originates at
A2A1J3-A as an operational indicator for the Synthesizer. A low (synthesizer
locked) from J2-8 to the base of Q1 will forward bias this transistor, placing a
high at the inputs of AND gate U1A-1 & 2 forcing its output pin 3 high. This high
is passed through R5, J10-22, PC3J1-22 forward biasing PC3Q2 causing
PC3DS2 to light. If Synthesizer A2A1 unlocks, a high will be sent to J2-8 which
ultimately shuts off the SYNTHESIZER LOCK indicator PC3DS2.
J10 – 23
LEVEL ADJ IN: This voltage is developed in amplifier U8A and sent through
LEVEL ADJUST PC3R16 and passed from this input (J10-23) to J8-7 as a
control level for variable attenuator PC1CR7/CR8 in the IF/Converter (see
J10-21 above).
J10 – 24
IF STATUS IN: This signal is taken from the output of U4B via resistor R19 for
control of IF STATUS LED PC3DS5. With the presence of an IF signal at the
input of PC1, a high is provided from PC1U4A to U4B, lighting IF STATUS LED
PC3DS5 via R19, J10-24, PC3J1-24, and PC3Q5. If the IF input is removed,
PC1U14 will then provide a low to U4B extinguishing the IF STATUS LED
PC3DS5 while forcing U3D and U2A low.