NHRC NHRC-4/M2, Installation And Setup Manual, Page: 7 / 22

NHRC-4/M2 User Guide
Copyright
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2001, 2005, NHRC LLC. All Rights Reserved. Page 3
2.1.2 Option 2: Modify the MASTR II System Board.
By cutting one trace and adding two wires to the MASTR II system board, the jumper
described in option 1, above, can be avoided.
Add a wire that connects P908 pin 2 to J902 pin 6 (the exciter's MIC HI input). Cut the trace
that leads to P908 pin 3 on the system board, and add a wire that connects P908 pin 3 to
J904 pin 9 (the CAS signal from the IFAS board). Install 0 ohm resistors (jumpers) R22 and
R38 on the NHRC-4/M2 board, enabling the TX audio and CAS signals on the J908
connector. Note that these jumpers may already be populated on your board. If you plan on
using the local microphone on the MASTR II's control head, install a 1.5K resistor in
location R38.
P908 Primary Radio Port Connections
P908
Pin #
NHRC-4/M2 Use System Board Modification
1 Discriminator Audio
2 Transmit Audio Add Wire to MIC HI On Exciter (J902-6)
3 CAS
Cut existing trace to P908-3.
Add Wire to CAS on IFAS (J904-9)
4 10V Regulated
5 no connection
6 PTT
7 CG Encode
Delayed PTT
9 Ground