How to hook up a Jackmate to a XTL1500

[touchtoomuch]

Can anyone help me with the rj45 cable that connects a Jackmate to the Accy connecter on a XTL1500. Radiomate sent me a pinout of their Jackmate but most doesn't make any sense. I have tried calling them multiple times, most of the time they never answer their phone!!! NICE!! Their picture says this.

Pin 1 Monitor ------------ I've got a trunking radio, don't think this one is needed.
Pin 2 PTT ------------- Easy one, Pin 16
Pin 3 Common ------- I'm guessing this would go to pin 14 analog ground.
Pin 4 Spkr Input ------ This one makes no sense, why would this Jackmate be connected to speaker output that can be controlled by the volume control of the radio, the trim pot on Jackmate or the volume control on the Jackmate. Why not use RX filtered audio?????? Would this be Speaker + Pin 20 ????????

Pin 5 Common --------I'm guessing this would go to pin 14 analog ground.
Pin 6 Mic Output ---- Easy one, Pin 23
Pin 7 Audio Return --- well, I'm guessing this should be called speaker negative????? So, are we talking Pin 26
Pin 8 Aux 12-18 VDC Input --- This one is really confusing!! Is this really needed. I mean, the Jackmate has a power supply!! So does this one really need to connect to pin 24.

Thanks