help with interfacing cdm750 and gm300 to repeater controller

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Da Man 215
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Joined: Thu Mar 01, 2012 4:09 pm

help with interfacing cdm750 and gm300 to repeater controller

Post by Da Man 215 »

I am trying to connect a cdm750 and a gm300 to an external repeater controller ( RC96). The gm300 is the receive radio. We are currently using a ra-1 repeater adapter which connects directly to the accessory connectors on the back of each radio which has been working fine. However, we have tried to connect the rc96 repeater controller and we are not having any luck. Here are the pins we are using on each, hopefully someone can point me in the right direction.

The gm300 ( rx radio )

using pin 8 as the cos
using pin 11 as the receive audio
pin 7 is ground, which we have tied pin 7 on the cdm750 and the ground on the controller to as well

the cdm750 ( tx radio)

pin 3 is PTT
pin 2 is the tx audio
pin 7 is ground

I am assuming there is no change in the cps that has to be made to the cdm pinouts since as I stated the ra-1 repeater adapter works flawlessly.

Ideas?

Thanks and happy Thanksgiving!
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Bigred
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Joined: Mon Apr 14, 2008 7:08 pm
What radios do you own?: Junk that comes and goes...

Re: help with interfacing cdm750 and gm300 to repeater controller

Post by Bigred »

Well what is happening or not happening for you. The pins listed are correct and should get you going. Double check your cable wiring. Make sure logic direction is set correctly in the RC96 for COS. /\/\ radios provide the proper logic levels (5V - 0V) by themselves so make sure there are no pull up or pull down resistors on the I/Os of the controller.

Lastly the RC96 is programmed correctly and enabled. right?
Lots and lots of watts...
Da Man 215
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Posts: 5
Joined: Thu Mar 01, 2012 4:09 pm

Re: help with interfacing cdm750 and gm300 to repeater controller

Post by Da Man 215 »

When it was first connected the ptt and the cos were active. I changed the state of the dip switch on the rc 96 which brought the ptt to the proper state which seemed to take care of that situation. But the state of the cos would not change when I changed the active high/low dipswitches on the rc 96. Ive checked the cable connections several time and know they are good. There are no pull up or down resistors on this controller and it came from a working environment. Thanks for the reply!
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