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MASTR Executive II Base and NHRC-3
This information is courtesy of Ray Vaughan, KD4BBM

Directions to connect the NHRC-3 Controller to a GE Mastr II base station.

Here's the inside of the radio with the controller installed:

mods005.jpg (23364 bytes)


Bill of Materials:
12 circuit terminal housing, .156 Digi-Key WM2110-ND
Pins for above Digi-Key WM2300-ND
8 conductor cable, 10" Any, shielded would be nice.

The controller uses a 10 pin .100 header for all connections in and out of the controller.    You'll need to make a very short cable to link the controller to the radio.  This should be no more than 10" long.   It will have the .100 header connector on one end and the 12 circuit terminal housing at the other.   Use heat shrink to keep a nice neat appearance.  Here's the pin-out for this interconnect cable.   It's very cool that only one connector is needed at each end.  If you end up with a few of these radios and controllers, you'll want to keep the connections standardized.   Then changing out a radio will only take a couple minutes.  



10 Pin Header Use My color
GE Mastr II  Base, J901
1 +13.8 Volts Red 5
2 +13.8 Volts    
3 CAS+ White 12
4 CAS- Yellow 3
5 PTT Violet 4
6 Ground Black 3
7 TX Audio Blue 1
8 TX Audio Rtn    
9 RX Audio Orange 9
10 RX Audio Rtn Shield 10

I mounted the controller with two screws into the space in the bottom to the radio where the remote control board would be installed.  Be sure to use insulated spacers.    The remote board is not needed to make a repeater. If you know this radio, you'll notice that I'm powering the board with the radio's regulated 10 V supply instead of the 13.8 V mentioned in the controllers documentation. Since the incoming voltage is regulated to 5V, feeding it with only 10V is fine. The current draw of the controller is very low, so you don't have to worry about overloading this supply which would normally feed the remote board.

mods006.jpg (21113 bytes)  Here's the controller mounted in the bottom of the chassis where the remote board would be installed.

Thanks to the NHRC guys for their work on this controller.


Except for portions owned by others, Copyright: Ray Vaughan, 2008