Operating Instructions

PIN NAME FUNCTION REMARKS

1 RSSI S meter output 0.5 - 2V signal strength indicator, 60dB range

2 SQF Squelch flag open collector output, ON (low) = no signal

3 AUDIO AF output

250mV p-p ±20% into 10kS

Note: The output audio is inverted with respect to

the ST600 (or similar Wood & Douglas product)

audio input.

4 DATA Data output open collector, no pull-up

Note: The data output is inverted with respect to

the ST600 (or similar Wood & Douglas product)

data input.

5 +5V +5 volt supply output 50mA maximum current drain

6 0V 0 volts common ground

RS232

I/P

serial programming

input

RS232 programming input

Note: inverted TTL level data can also be used. If

not used, leave not connected, or connect to 0/ V

8 RB1

parallel frequency

select

internal pull-up to +5V, active low

9 RB2

10 RB3

Connector PL3 pin detail