Display/Monitor Interface (PC3J1)
Jack – Pin #
Function
2
6
18
J10 – 16
LINEARITY CORRECTOR ACTIVE LED: With Linearity Corrector switch
PC2S1 in the ENABLE position, the corrector circuits active with +15V divided
down to +5V and presented to input pins 9 & 10 of U1C via PC2R64, PC2J3-3,
J7-3 and R36. The resulting high at U1C-8 is forwarded to J10-16, PC3J1-16
and PC3Q3 used to turn on front panel LINEARITY CORRECTOR light PC3DS3.
J10 – 17
PWR REFERENCE IN: This voltage, proportional to the monitored output
power, originates from either the Exciter (A3J3-5) or transmitter (A7A1J3-5)
Metering Detector and is buffered by U5A or U7A, respectively. The voltage
connected to JP1 is forwarded to the front panel AGC ADJUST PC3R15 through
J10-19, PC3J1-19, amplifier PC3U1, PC3J1-17 to J10-17. This PWR
REFERENCE signal reaches PC1J6-8 of the IF/Converter through J8-8 and acts
as the reference for the IF/Converter’s output AGC loop by controlling variable
attenuator PC1CR9/CR10 and compensating for any power variations occurring
at the Exciter’s/transmitter’s output. If for some reason the Exciter’s/transmitter’s
output power were to drop, the positive voltage at J8-8 would be reduced. The
change in level reduces the attenuation provided by PIN diodes PC1CR9/CR10
in proportion to the power decrease, thereby bringing the output power back to
its appropriate operating level. In the case where the Exciter’s/transmitter’s
output increases above its rated output, the PWR REFERENCE voltage at J8-8
will increase causing attenuator PC1CR9/CR10 to increase resistance,
decreasing the output signal level to its proper value.
J10 – 18
AGC MANUAL LED: This output line connected to U4C-8 via R23 controls front
panel AGC ACTIVE LED PC3DS6 through PC3J1-18 and switching transistor
PC3Q6. The AGC ACTIVE indicator will be lit when concurrent highs are pro-
vided from the OPERATE/SWEEP switch S1 (OPERATE position), from the
AMP STATUS IN line at J4-1, from the front panel AGC/MANUAL switch PC3S2
(AGC position) input at J10-9 and from the REMOTE AGC ON/OFF line at J5-6
forcing the output of U4C high.
J10 – 19
PWR REFERENCE OUT: This voltage, proportional to the monitored output
power, originates from either the Exciter (A3J3-5) or transmitter (A7A1J3-5)
Metering Detector and is buffered by U5A or U7A, respectively. The voltage
connected to JP1-2 is forwarded to the front panel AGC ADJUST PC3R15
through J10-19, PC3J1-19, amplifier PC3U1, PC3J1-17 to J10-17. The signal
reaches PC1J6-8 of the IF/Converter through J8-8 and acts as the reference for
the IF/Converter’s output AGC loop by controlling variable attenuator PC1CR9/
CR10 and compensating for any power variations occurring at the Exciter’s/
transmitter’s output. If for some reason the Exciter’s/transmitter’s output power
were to drop, the positive voltage at J8-8 would be reduced. The change in level
reduces the attenuation provided by PIN diodes PC1CR9/CR10 in proportion to
the power decrease seen at the Exciter’s/transmitter’s output, thereby bringing
the power back to its appropriate operating level. In the case where the trans-
mitter’s output increases above its rated power, the PWR REFERENCE voltage
at J8-8 will increase causing attenuator PC1CR9/CR10 to increase resistance,
decreasing the Exciter’s/transmitter’s output signal level to its proper value.