Variations on the 13-pin ACC jack pinout

There are a handful of weird variations in the 13 pin accessory jack on Kenwood radios.

Radio	1	2	3	4	5	6	7	8	9	10	11	12	13
TS-140	NC	NC	Receiver output / 300mV / 4.7k	Output ground	Squelch control	NC	NC	Ground	Transmit PTT - MIC mute	NC	Data Input / 10mV	Input ground	PTT (not MIC mute)
TS-440	NC	NC	Data output / 300mV / 4.7k	Output ground	NC	NC	NC	Ground	MIC mute	NC	Data input - docs say 500mV or less; end up needing 1v PtP to see full SSB modulation	Input ground	PTT
TS-450	NC	RTTY input	Receiver output / 300mV / 4.7k	Receiver output ground	Squelch control	NC	NC	Ground	Transmit PTT - MIC mute	NC	Mic audio input	Input Ground (via 0.001uF cap)	PTT (not MIC mute)
TS-680	NC	NC	Receiver output / 300mV / 4.7k	Output ground	Squelch control	NC	NC	Ground	Transmit PTT - MIC mute	NC	Data Input / 10mV	Input ground	PTT (not MIC mute)
TS-690	NC	RTTY input	Receiver output / 300mV / 4.7k	Receiver output ground	Squelch control	NC	NC	Ground	Transmit PTT - MIC mute	NC	Mic audio input	Input Ground (via 0.001uF cap)	PTT (not MIC mute)
TS-711	NC	NC	Data out / 300mV+ at 4.7k	Data GND	NC	NC	NC	NC	Mic Mute	NC	Data Input / 500mV	Data Input GND	PTT
TS-811	NC	NC	Data out / 300mV+ at 4.7k	Data GND	NC	NC	NC	NC	Mic Mute	NC	Data Input / 500mV	Data Input GND	PTT
TS-940	ACC SW	ACC SW	Data out / 300mV+ at 4.7k	Data GND	NC	NC	NC	GND	Mic Mute	NC	Data Input / 500mV	Data Input GND	PTT
TS-2000	Sub-receiver output / 10k	RTTY input	Main receiver output / 10k	GND	Main receiver squelch control	NC	Sub-receiver squelch control	GND	Transciever PTT - MIC mute	NC	Mic audio input	GND	PTT (not MIC mute)

Differences

• Pin 13 is PTT with the front MIC not muted - eg for a foot pedal.
• Some radios (TS-440, TS-711, TS-811, TS-940) have a separate pin (9) that doesn’t PTT - it just mutes the MIC
• Other radios (TS-690, TS-2000) use pin 9 for PTT + Mic mute

Notes

• The TS-440 needs a comparitively obscene amount of audio input to work compared to the other radios. I’ve had to feed it more than 1v ptp to get it to do the right thing. This requires the “higher audio level” jumper on the Signalink USB to work right.
• TS-2000 could do with some more description as to what each does!
• The TS-450 / TS-690 input ground (pin 12) isn’t ground ground; it’s actually through a 0.001uF capacitor. I’m assuming they’re trying to do a bit of ground loop avoidance here but still, seems a bit weird.
• The TS-450 / TS-690 input levels by default are super sensitive and any RF leaking in via poor shielding / choking will distort audio. A common fix is to adjust the PKD pot (VR13) on the IF board to make it require more audio drive.