PIN	Function	Direction	Notes and limitations
1	CTCSS logic output (active high)	Out	Current limited, includes a pull-down
2	Ground - for power, audio and logic	Both	The four mounting holes are also at ground potential
3	Power supply positive (+7 to +16 VDC)	In	7 - 16 VDC typical, up to 24 VDC maximum
4	RX - TX mode switch	In	Ground for TX (encode only) - Open for decode
5	Transmit audio input - to HP filter	In	Operates only in TX mode
6	Transmit audio output - from HP filter	Out	Operates only in TX mode
7	Receive audio output - from HP filter	Out	Operates only in RX mode
8	CTCSS logic output (active low)	Out	Includes a current limited pull-up
9	Discriminator audio input - High Pass Filter input	In	Raw discriminator audio input for both decoder and RX filter
10	CTCSS tone output - Encode level adjusted by VR1	Out	Operates only in TX mode
11	PTL (push to listen)	In	See MX465DW data sheet for operation
NOTE:	Use outputs A - B only when the logic outputs above cannot be used!
A	Alternate Open Collector CTCSS output (active high)	Out
B	Alternate Open Collector CTCSS output (active low)	Out