Vertex Standard VXR-7000 Service Manual page 4

Operating Manual Reprint
ACC Connector Port
The VXR-7000 repeater is provided with a 25-pin DB-
25F female connector for interconnections to accesso-
ries. Use a DB-25M 25-pin male connector to connect
accessories to the repeater. The pins on the accessory con-
nector are explained in detail as follows:
Pin 1: GND
Chassis ground for all logic levels and power supply
return.
Pin 2: +13.8 V [Power Supply]
This pin provides 13.8 Volts, 1.0 A, regulated DC from
the repeater supply. Use a 1 A fuse in the external
device's DC line to prevent damage to the repeater.
Pin 3: TX AF IN [Analog Transmitter Input]
(Voice Band: 300 ~ 3,000 Hz)
Input impedance is approx. 600 Ω. This audio is in-
jected before the splatter filter stage, so excess signal
input levels are clipped.
Use shielded cable to connect to this pin, and connect
the shield to GND.
Pin 4: TONE IN [Transmitter Input]
(Sub-audible Band: 6 ~ 250 Hz)
The input is high impedance (approx. 22 kΩ). Inject-
ing too high a voltage here causes over-deviation of
CTCSS or DCS, degrading performance. Use shielded
cable to connect to this pin, connecting the shield to
GND.
Pin 5: N.C. (No connection.)
Pin 6: DISC OUT [Analog Output]
(Wide-Band: 0 ~ 3,000 Hz)
Received signals with standard deviation produce
approx. 1 Vp-p audio at this pin. The output imped-
ance is approx. 600 Ω, and is extracted before the de-
emphasis and squelch circuitry. Use shielded cable to
connect to this pin, and connect the shield to GND.
4
Pin 7: GND
Chassis ground for all logic levels and power supply
return.
Pin 8: RSSI [Analog Output]
A DC voltage proportional to the strength of the sig-
nal currently being received (Receiver Signal Strength
Indicator) is provided on this pin. This low imped-
ance output is generated by the receiver IF sub-sys-
tem and buffered by an internal op-amp. Typical volt-
ages are graphed as follows:
Pin 9: COAX. SW [Logic Output (Active Low)]
This output is intended for controlling an external co-
axial switching relay. It is an open collector output
which can sink approx. 10 mA when active. This sig-
nal only switches if the repeater has been programmed
for "SIMPLEX" mode. If programmed for "DU-
PLEX," the signal remains open (high impedance) at
all time.
Pin 10: N.C. (No connection.)
Pin 11: NSQ DET
This is an open-collector, active-low output capable
of sinking about 10 mA. It indicates that the receiver
squelch is open. If the squelch control is properly set,
this indicates a carrier on the receiver channel.
ACC Jack
DB-25 Pin Numbering
VXR-7000 UHF Service Manual