RA-35 DB9 Pinout:

1 - Right (Aux or Tone) Output

2 - Left (Main or Voice) Output

3 - COS Logic Input - (pull near ground required for valid input)

4 - CTCSS Logic Input - (pull near ground required for valid input)

5 - PTT Output

6 - Discriminator / Detector or Receiver Audio Input - (level controlled by potentiometer)

7 - Local Control (Control Revert) Logic Output (Use with JU1 - see note below)

8 - Ground - (Digital and Analog)

9 - External Audio Amplifier Power (6 to 15 VDC) (Use with JU2 - position B)


Local Control is a logic option that can enable a secondary control method.  Some repeaters 
only require one logic lead change to enable internal controls. Not all repeaters have this 
control revert option, but for the ones that do, the RA-35 can feed such a line directly.  
This feature of enabling internal controls will allow the repeater to operate locally if the 
Asterisk application, computer, or RA-35 should fail.  JU1 controls the polarity of this 
function, explained below.

Jumper JU1 - Control Revert logic polarity.
Position A = DB9 pin 7 Logic is high when COMM OK LED not lit.
Position A = DB9 pin 7 Logic is low when COMM OK LED lit.
Position B = DB9 pin 7 Logic is low when COMM OK LED not lit.
Position B = DB9 pin 7 Logic is high when COMM OK LED lit.

Jumper JU2 - Audio amplifier powering.
Position A = Amplifiers powered from USB 5VDC. Suitable for many radio applications where 
  the maximum required P-P voltage doesn't exceed 5 volts.
Position B = Amplifiers powered from external source 6 to 15 VDC. Some radios, like the 
  Yaesu System Fusion, requires more than 5 volts P-P of audio. Many radios have a source of 
  10 to 15 volts readily available. Must be well filtered but regulation isn't necessary as 
  long as enough current is available for the load. Driving speakers will require a power 
  source capable of several hundred mA., depending on speaker impedance and desired listening 
  level.