http://www.open.org/~blenderm/syntorx9k ... ml#x9k4246
http://www.open.org/~blenderm/pac.html#pacblwir
(the Syntor X 9000 NKN6371A Cable)
As for daisy chaining the cables. The PAC-RT cable T-connector pin 32 (B-) ground is missing in the Siren/PA cable. The PAC-RT cable T-connector pin 6 should work because the Siren/PA cable jumpers pins 6 and 7 together. You can check the Siren/PA schematic and see if the circuit board provides a ground connection to pin 32. If it does not, you can fix it by moving the PAC-RT cable T-connector pin 32 to pin 8. If there is enough slack in the wire you might be able to physically swap the pins inside the T-connector housing.
Of course it is assumed you are using a standard negative ground power system.
The problem is pin 24 (Spare 1) is missing from the Siren/PA cable. Spare 1 is used to connect the Systems 9000 control head (modification required) to the PAC-RT microphone PTT input. This allows PAC-RT users to hear anything transmitted directly from the mobile using the mobile microphone. Daisy chaining the two cables will not support this listening function.
I looked for the 3 deep extended connector knob part number a long time ago. I was never able to verify the part number I did find, so I never included it in the web site. I do remember Motorola wanted around $ 80 for it. I know they were used on the primary radio of a Systems 9000 dual radio (not the HHCH dual radio) that also has a Siren/PA. This required the Siren/PA T-connector cable and secondary radio T-connector cable to be stacked together with the control head cable on the primary radio connector.
The answer is yes, you can run 2 T-Connectors + plus the original control cable on a Syntor 9000. Motorola did it.