Specifications

151
Connector Details
Connector J4 (Tx)
This connector contains connections for the transmit interface. If a 2-wire system is being
used, then the receive audio connection is also made here.
The pin connections for the J4 connector are listed in Table 5.
Table 5: Transponder Board Connector J4 Pinout
Pin Description
Pin 1
(XMIT BUSY)
This pin is a cross-busy input. If this pin is externally driven to ground,
the Model 6203 is prevented from transmitting. This pin is never driven
low by the Model 6203.
Pin 2
(GND)
This pin is connected to Model 6203 chassis ground.
Pin 3
(AUX RX AUD B)
Typically grounded by installing a jumper to J4 pin 2
Pin 4
(AUX RX AUD A)
If the VoIP Intercom option is installed, the Line Out audio (P4-pin 5)
from the IP Interface board is typically connected here.
Pin 5 This pin is not connected.
Pin 6 This pin is not connected.
Pin 7
(GND)
This pin is connected to Model 6203 chassis ground.
Pin 8
(XMIT PTT)
This pin is the Model 6203 Push-to-Talk output. It is an open drain
output that is grounded when the Model 6203 starts transmitting and
stays grounded until finished. At all other times this pin is open. THIS
FUNCTION IS NOW PERFORMED BY THE IP INTERFACE
BOARD, P4-pin 1.
Pin 9
(-AUD Tx)
This pin is the negative side of the transformer-coupled audio output. It
is typically grounded to J4 pin 7. The output audio levels are adjusted by
potentiometers FFSK OUT (R108), MIC (R63).
Pin 10 This pin is not connected.
Pin 11
(+AUD Tx)
This pin is the positive side of the transformer coupled audio output.
Pin 12 This pin is not connected.