Need help! SM50/SM120 repeater!

[Railcon]

I'm trying to setup a low cost repeater for now using an SM50 and SM120. I'm new to repeaters and need help with the programming. The SM120 was supposedly already set for RX and the SM50 was suppose to be TX but when I key up my portable, the SM120 does nothing and the SM50 receives as if it was a stand alone mobile. I'm using a "Double Connector Cable For Motorola GM300 GM950E GM950I GM338 SM120 TX–RX Radio" from Ebay, the cable labeled TX/RX-2, it came with the setup. I'm also using 2 antennas for the time being spaced about 80' apart in the yard. I'm reasonably sure it's an RSS issue but I don't know what the setting should be and I've never had to program anything like this before. I have the RSS, just not the knowledge to make these work as intended.
Any help would be greatly appreciated.

[Bill_G]

Is your portable programmed correctly? Who programmed the repeater radios? Did you guys discuss PL tones?

[tdats]

It sounds like your portable is programmed to transmit on your repeater output (talk around), or your mobiles are programmed wrong. If you have a mic for the mobiles, try to key your output radio and see if you can hear it on the portable. If so, then that radio is probably correct and the issue is your portable.

I am working on a repeater using a couple of mobiles myself, and managed to miss-program it a couple of times.

[Railcon]

Ok, I'll try reprogramming my portables and see what happens. I is/was under the impression the mobiles may be wrong, there seems to be way to many "nulls" on both radios. I guess I was kind of hoping someone could send some screenshots of the mobile RSS settings. Like I say, I'm new at attempting repeaters with mobiles!

[wavetar]

It's a pretty straight forward process once you wrap your head around what's needed.

The SM120 needs to provide only two things to the SM50...some sort of 'trigger' to key the SM50 upon receiving the carrier from the portable, and to forward it's received audio onto the SM50 for transmission.

The SM50 requires a ground on pin 3 to key up. Follow your ebay cable back from that pin, to where it goes into the SM120. Whatever that pin is (let's say pin 8, for example) then in RSS you need to set SM120 pin 8 to "carrier detect" or "carrier/PL detect" and set the active state to "low". This will output a ground when a valid carrier is received, causing the SM50 to key it's transmitter.

The SM50 uses Pin 2 as the aux TX input. The SM120 should by default (not a programmable option) output detector audio on it's pin 11. The ebay cable should connect these two pins.

The radios also need to share a common ground. I'm assuming you have them on a common power supply, but the ebay cable will also likely have Pin 7 (ground pin) from both radios connected together anyway.

[Railcon]

Thanks for the help guys! I got it up and running. the biggest issue I had was with the portables being programmed incorrectly, next time I do it myself in the first place. The Ebay cable had an issue also, there are so many out there that "claim" to do the job but don't! I had ordered a different cable and everything was in order according to what wavetar mentioned. Now to do the same thing with a couple of M216's! The RSS on these have more options but I'm rather confident I can make them work. I'm starting small for now and working my way up to building a real repeater for my home location on GMRS and possibly another in the great north woods of WI!