Specifications

7-8
Positive Current Transmitter PTT
The CAT-1000B keys the transmitter by grounding the PTT line. Some transmitters
require a DC current usually from a 12volt DC supply to key. In these cases a
switching device must be installed between the transmitter and the CAT-1000B Push-to
Talk output at J4-10. Figure 7-4 describes two possible circuits that will supply the
transmitter. Use caution when connecting this circuit. Do not apply +12VDC directly
to J4-10. This will result in damage
to U7.
2.2K
2.2K
TRANSMITTER
+12VDC
+12VDC
TRANSMITTER
PNP
POWER TRANSISTOR
RELAY (12VDC)
CAT-1000 J4-10
PUSH TO TALK
K1
CAT-1000 J4-10
PUSH TO TALK
Figure 7-4