Exciter Remote Interface (A2J5)
Jack – Pin #
Function
2
6
36
A2PC3DS8 will then turn off and IF input attenuator A2PC1CR7/CR8 will be
returned to normal operating levels.
J5 – 7
FWD POWER: The outgoing voltage at this pin from buffer U4A is proportional
to the forward output power of the transmitter according to the voltage supplied
by Metering Detector A7A1J3-5 via FORWARD POWER INPUT J6-5. This
metering information is then forwarded through A2PC4J5-7 to pin 3 of buffer
A2PC4U7A. When the Exciter is driving higher power equipment, as in the
TTU500FA, pins 1 & 3 of jumper A2PC4JP1 are closed sending the metering
voltage from A2PC4U7A to the front panel AGC ADJUST amplifier A2PC3U1
through A2PC4J10-19 and A2PC3J1-19. From AGC ADJUST PC3R15, this
PWR REFERENCE signal reaches A2PC1J6-8 of the IF/Converter by
A2PC3J1-17, A2PC4J10-17 and A2PC4J8-8. This voltage now acts as the
reference for the IF/Converter’s output AGC loop by controlling variable
attenuator A2PC1CR9/CR10 and compensating for any power variations occur-
ring at the transmitter’s output. At the same time, the voltage at J6-5 is supplied
to FORWARD POWER meter adjust amplifier U5A, the gain of which is dictated
by the setting of potentiometer R31. Connected to front panel FWD/REFL meter
switch at S1-3, the output of U5A is essentially utilized to deflect the RF POWER
bar graph meter DS5/DS6/DS7 when S1 is in the FWD position. The information
supplied by U5A is fed from S1-3 & 1 to four quadrant multiplier U10 which
squares the voltage so that the bar graph will respond as a power meter rather
than a volt meter. The signal is then amplified by U6A before distribution to bar
graph drivers U7/U8/U9. With the TTU500FA transmitter operating at its rated
power and FORWARD POWER LED DS8 lit, FWD METER ADJUST R31,
accessible through the Control/Metering panel, is adjusted for a 100% indication
on the RF POWER meter.
J5 – 8
GND: From A2J5-8
Power Supply Interface (PS1J2)
Jack – Pin #
Function
J7 – 1
+5V: From PS1J2-3
J7 – 2
15V: From PS1J2-6
J7 – 3
+15V: From PS1J2-1
J7 – 4
GND: From PS1J2-5
Metering Detector Interface (PS1J2)
Jack – Pin #
Function
J6 – 5
FORWARD POWER INPUT: This input voltage is proportional to the power
being produced at the RF OUTput of the transmitter (A7DC1J2) and is supplied
by the Metering Detector’s FWD PWR connection A7A1J3-5. The signal is then
supplied to buffer amplifier U4A and FORWARD POWER meter adjust amplifier