Jump to content
  • 0

Technically Speaking, How Does Midland’s Group Mode Work?


mbrun

Question

I own a collection of Midland GXT1000 Radios FCC ID #MMAGXT50. These radios have a proprietary ‘Group Mode’ feature that allows two way communications between radios with the same Group Mode setting. In general, radios in Group Mode behave similar to radios that merely use CTCSS or DCS codes.

 

I have assumed for some time that this Group Mode is really nothing more than a different way of assigning the various CTS an DCS already built into the radio. However, when I attempted to confirm this I had no success. I tested this by enabling group mode on a transmitting unit and then trying all the different CTCSS and DCS codes on a receiving radio. The receiving radio never broke squelch when any CTSSS or DCS was active.

 

So what I am trying to figure out is, technically speaking, what specifically is Midland doing to achieve Group Mode behavior? Anyone out there know?

 

 

Sent from my iPad using Tapatalk

Link to comment
Share on other sites

5 answers to this question

Recommended Posts

  • 0

Does the radio programming software help file give any clues? Other radio manufacturers offer a similar feature. It typically works using a proprietary signaling method.

 

For example one manufacturer let’s users program in a multi digit DTMF code, like a touch tone telephone number, and only radios with a matching code will open the squelch so you can hear the audio. All other radios the audio will remain muted.

 

Some others use two-tone or five-tone signaling. I think Motorola uses their own proprietary system MDC.

 

https://en.wikipedia.org/wiki/Selective_calling

 

 

 

Link to comment
Share on other sites

  • 0

The GXT1000 does feature programming software. It is only front panel controllable. Currently this is still Midland’s top-of-the-line GMRS radio.

 

I have searched the web to no avail. I suppose if it were targeted for the advanced user there might be technical information widely available.

 

 

e5b6d3fe6670d34fa7aefe2cd659cb46.jpg

 

 

Does the radio programming software help file give any clues? Other radio manufacturers offer a similar feature. It typically works using a proprietary signaling method. For example one manufacturer let’s users program in a multi digit DTMF code, like a touch tone telephone number, and only radios with a matching code will open the squelch so you can hear the audio. All other radios the audio will remain muted.Some others use two-tone or five-tone signaling. I think Motorola uses their own proprietary system MDC. https://en.wikipedia.org/wiki/Selective_calling

 

Sent from my iPad using Tapatalk

Link to comment
Share on other sites

  • 0

So I am wondering if Midland is actually using non-standard CTCSS and DCS Codes for Group Mode functionality.

 

I don’t currently have a way to scan for the codes that are actually being broadcast, but I would I suppose that is a possibility.

 

What other times of continuous data transmission does the FCC allow to be broadcast via GMRS? I know Text Messages, Location Data and PL codes are all permitted. Anything else?

 

 

Sent from my iPad using Tapatalk

Link to comment
Share on other sites

  • 0

Yes, there is signaling feature you can take advantage of while in group mode (a useless implementation IMO).

 

Coincidentally, the number of group codes available on the radio is One more than the total number of DCS and CTCSS codes available on the radio. Valid codes range from 00-142.

 

 

FWIW, I seem to recall reading somewhere that the Group Mode feature was for signaling other radios, but not for talking.

 

Sent from my iPad using Tapatalk

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Answer this question...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use and Guidelines.