GM300 repeater help

The General forum is where users can discuss any topic regarding Motorola communications equipment - hardware, software, etc. There are also several focused forums on this board, so please take the time to ensure that your questions doesn't fall into one of those categories before posting here!

Moderator: Queue Moderator

Post Reply
rrobins
New User
Posts: 3
Joined: Thu Oct 25, 2007 3:42 pm
What radios do you own?: Motorola,Vertex,Kenwood,Maxon

GM300 repeater help

Post by rrobins »

I have found some good references on this site about making a GM300 repeater system but needing some help as I am still new at this.
My setup is this
1.I have two GM300s 16 channel setup in the repeater mode with a duplexer.
Note: works but when transmitting through the repeater from truck to truck the audio sounds like it overdriving the speaker, allot of base.
2.I read the web link on Non-R.I.C.K. Interface Cable and are these pins the only ones I need to hookup for the CROSS-CONNECTION between the radios or are the others? Radio1 Radio2
PIN 3 PTT ___________________ PIN 8 COR
PIN 8 COR ___________________ PIN 3 PTT
PIN 5 TX Audio __________________PIN 11 Disc Audio
PIN 11 Disc Audio __________________PIN 5 TX Audio
PIN 7 Gnd ___________________ PIN 7 Gnd
3. I have cut the watts on the TX radio and out the duplexer am getting almost 25 with good 4-inch fan mounted to the heatsink as this will be a low use repeater.
Note: I have read a couple of different things about putting a trim pot in but still not sure if I am doing this between my PINs or I need to do this on the logic board it self. Correct me if I am wrong but it almost seems like the receive audio gain is over doing it. The voices are not distorted just like it’s too much. Any help for this novice would be appreciated.
Will
Posts: 6823
Joined: Tue Sep 04, 2001 4:00 pm

Re: GM300 repeater help

Post by Will »

Number 1 you do NOT use the discriminator out put or the pin 5 input for what you are trying to do. Pin 5 bypasses the transmitter audio (modulation) limmiter stage and will over dev the TX.

Do a search here for Todd's hookup.
rrobins
New User
Posts: 3
Joined: Thu Oct 25, 2007 3:42 pm
What radios do you own?: Motorola,Vertex,Kenwood,Maxon

Re: GM300 repeater help

Post by rrobins »

Thanks for the reply will look for that, I did find some useful things on this link

http://www.storm.ca/~nand/990/RICK/rptr.pdf
Will
Posts: 6823
Joined: Tue Sep 04, 2001 4:00 pm

Re: GM300 repeater help

Post by Will »

That PDF is what I refered to, not a bad way to do it.. works fairly well.

Pin 11 should provide muted filtered recive audio.
rrobins
New User
Posts: 3
Joined: Thu Oct 25, 2007 3:42 pm
What radios do you own?: Motorola,Vertex,Kenwood,Maxon

Re: GM300 repeater help

Post by rrobins »

Got one put together today and it controls the audio real well. Going to make three backup repeaters just in case our mains go down should be a good temp option to have. I have looking to see if it's possible to do the Motorola Radius M1225 4 channel mobiles but I don't see it in the software for some kind of generic repeater setup.
Post Reply

Return to “General Motorola Solutions & Legacy Radio Discussion”