User's Manual Part 2

T6T 300 Watt VHF Transmitter Page 88 Installation
MARC Connector
The MARC connector is a 9-way D-type socket used to connect the transmitter to a MARC remote site
equipment, or it can also be used for normal remote operation.
As an alternative to using this connector, the RJ48 style MARC Audio and MARC Data connectors can
be used to provide the same functions.
The MARC connector pin-out is shown below and detailed in Table 18.
Note:
The line level figures shown for the MARC connector are the limits when testing the transmitter
using a sine wave; the line level will be 10 dB above the line level setting. See the information
supplied under the heading ‘Line Level Setting’ in Operation.
Table 18 MARC Connector
Pin Number Signal Characteristic
1 Ground 0 V.
2
3
Audio line in (+)
Audio line in (-)
Balanced 600 ohm, -30 to +10 dBm.
Phantom keying can be superimposed on the audio
lines. See Fig 27.
4 PTT input Remote PTT signal input. See Fig 26.
5 Output supply This output is between 21.6 and 32 Vdc (nominally
28 V) fused at 500 mA.
6
7
Data in (+)
Data in (-)
RS422 differential asynchronous data at 9600 baud,
8 data bits, 1 stop bit, no parity, no handshaking.
8
9
Data out (+)
Data out (-)
RS422 differential asynchronous data at 9600 baud,
8 data bits, 1 stop bit, no parity, no handshaking.
Pin-out of MARC connector looking into the mating face of the
chassis mounted socket.
A suitable free plug is detailed in Table 14 on page 70.
15
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