Using MDC1200 on GMRS in Louisiana

If you’re running MDC on your GMRS radio, here’s how we do it locally in Louisiana:

What is MDC?

MDC (Motorola Data Communications) is a digital ID system that lets others see who’s transmitting. It’s super handy for identifying radios.

Your MDC ID is 4 digits:

First digit = radio type
0 = Base station
1 = Mobile (vehicle)
2 = Portable (HT/handheld)
3–D = Special uses (e.g., multiple HTs or a base station at secondary location)
Example: Thomas (WSET302) has a home base station with ID 0302 and a classroom base station with ID C302.

Last 3 digits = your call sign
Just use the last 3 of your GMRS callsign.
Example: My callsign is WSEP298
My mobile is: 1298
My base station is: 0298
Note: Some radios don't show the leading 0. So my base station may show up as ID 298.

Pre vs Post ID:

This is when your radio sends the ID:

Pre-ID: Sends the MDC burst before you talk. It’s better for visibility but you must wait for the beep to avoid cutting off your words.
Post-ID: Sends it after you finish. It doesn’t interrupt speech, but it can be missed if someone keys up right after.

Talk Permit Tone:

Use a Talk Permit Tone to know when to start speaking:

Short tone = quick beep when your ID finishes.
Long tone = holds a tone until the ID is done.

I personally use Pre-ID + short sidetone — after a while, waiting for the beep becomes second nature. Hope this helps you set up MDC on your radio and stay active in the Louisiana GMRS scene!