SABER ACCESSORY CONNECTOR PINOUT (looking the back of the radio):
(.) 1 2 3 4 5 6 7 8 9 10 11 12
The () is ground around remote antenna centre pin.
1 EXT SPKR+ 2 EXT SPKR- 3 DATA 4 EXT MIC 5 /WE 6 BUSY 7 OPT SEL* 8 OPT B+ 9 KEY 10 KEYLOAD 11 DVP CLK/AUX TX 12
* The OPT SEL pin follows the following table:
|All Internal, STD Operation||5VDC|
|EXT MIC and SPKR, STD ANT||1.24VDC|
|EXT MIC, SPKR and ANT||2.5VDC|
|EXT ANT ONLY||3.74VDC|
According to the schematic, there is a 20 kohm resistor from REG +5VDC tied to the OPT SEL pin. This means that in order to select one of the above modes, you will need to tie the OPT SEL pin to ground through a zener diode(s)(and with no connection the pin floats to 5V which is STD operation).