2
6
13
Power Supply Module Interface (PS1TB2)
Jack – Pin #
Function
J3 – 1
GND: Ground from TB1-4
J3 – 2
GND: Ground from TB1-4
J3 – 3
15V: From PS1TB2-1 and distributed to circuits and interface jacks on PC4
J3 – 4
+5V: From PS1TB2-9 and distributed to circuits and interface jacks on PC4
J3 – 5
+15V: From PS1TB2-4 and distributed to circuits and interface jacks on PC4
J3 – 6
+28V: From PS1TB2-6 and distributed to interface jacks on PC4
Metering Detector Module Interface (A3J3)
Jack – Pin #
Function
J9 – 1
REFL PWR: Metering voltage proportional to the reflected power found at the
output of the Exciter is provided from A3J3-1, buffered by U5B and amplified by
U6B according to the setting of REFL PWR METER ADJ potentiometer R33.
This voltage is sent to J10-14 but is not utilized in this application. When the
Exciter is not driving higher power amplifiers, pins 1 and 2 of jumper JP2 are
closed sending the metering voltage to pin 6 of U6A, the VSWR overload refer-
ence amplifier. When the Exciter is driving higher power amplifiers, JP2 pins
2 & 3 are connected, bringing reflected metering voltage in at J5-3 from the
detector (A7A1) monitoring the output of the transmitter. With high reflected
output power, the voltage at U6A-3 will exceed the reference at pin 2, a level
determined by VSWR OVLD REF potentiometer R12 which is typically set for
25% reflected power. Output pin U6A-1 will turn positive causing output pins
5 & 6 of flip-flop U9A to change states. As U9A-5 goes negative, gate U2D will
output a low on pin 11 sending U2A-3 and U8A-1 low. The low at J10-21
proceeds to PC3J1-21, LEVEL ADJUST PC3R16, PC3J1-23, J10-23, 8-7 and
PC1-7, causing buffer PC1U9 to set IF input attenuator PC1CR7/CR8 at maxi-
mum attenuation. This action reduces the output power of the Exciter and trans-
mitter approximately 50dB to insure that no amplifier damage occurs due to
excessive output VSWR. Concurrently, the high generated at U9A-6 is used to
light VSWR OVERLOAD indicator PC3DS8 via J10-11, PC3J1-11 and transistor
PC3Q8.
J9 – 3
+5V: To A3J3-3 from J3-4
J9 – 4
GND: Ground to A3J3-4
J9 – 5
FWD PWR: Voltage proportional to the forward output power of the Exciter is
provided from A3J3-5 to buffer U5A and amplifier U7B whose gain is controlled
by FWD PWR METER ADJ potentiometer R42. R42 is adjusted so that U7B
provides enough voltage to register a 100% reading on the front panel RF
POWER meter PC3DS9/10/11 when the Exciter is providing its rated output
power. This voltage is supplied to the meter through J10-15, PC3J1-15, squaring
circuit PC3U2 and amplifier PC3U1.
