Radius/ Gm300 help

Hi
Picked up a used Radius-Gm300 it has 7 channels on it and I would like 16 like my other radios / Just how do I add channels to this radio ?? > And could someone please tell me what Version of CPS to use
The Radius and gm300 and maxtrac will not read this radio. And I also see someone has soldiered pins
#8and #10 together on this Any Ideas Why
Thanks

I have three Radius P100’s. I took them to the local radio shop and had them program them with the local repeater frequencies.

ok thanks/ guess I will have to go that way