Same model 2-way uses different channel numbers

I have a set of Midland GXT1000 2-ways from maybe 10 years ago. Recently, I purchased another set, same model, for my daughter and husband. If I set all of them on channel 1, the two old ones talk to each other, and the two new ones talk to each other, but the old and new don’t talk to each other.

For kicks, I set the new ones on channel 1, then hit SCAN on the old ones. It latched on to channel 15 of the old, and they were able to communicate properly. So I started mapping the channels:

NEW Unit OLD Unit
1 15
2 16
3 17
4 18
5 19
6 20
7 21

16 1
17 2
18 3
19 4
20 5
21 6
22 7

None of the other channels match up with any other channels.

Am I doing something wrong here? The settings are identical except that on the old model, when you hit MENU, it displays 1 00…the 1 being the channel. But I cannot affect the 00 at all. The new model only shows the number 1.

Any help would be appreciated.

That’s pretty normal with such a time delay between purchases. Over the years, the allocations change, and some channels and their tone systems get updated. Sometimes it’s because certain channels become too popular, and the complaints of ‘interference’ or’ less range’ grow. Most users are not remotely technical and don’t understand that there are limited numbers of channels and available tones, and they want just their own users and nobody else. So when a channel gets used by more and more makes, it is less attractive, so they move things around. The time scale could be very short if you bought the last old stock and the first new stock. It also means buying one radio as an extra can never be guaranteed to work. Just how it is I am afraid.

Thanks for the response. That makes sense. I can live with that.

10-15 years ago there were two different ways to number the channels available for FRS/GMRS. The Icom bandplane (which was pioneered from the F21-GM due to a technical limitation of the F10 series Icom radios) where the 8 GMRS repeater capable channels came first and then the 7 interstitial channels (which were shared by the two services) followed by the 7 FRS only channels. Then there was the Talkabout bandplan which put the 7 interstitial channels followed by the 7 FRS only channels and then the 8 repeater channels.

When the rules got re-written a few years back, Talkabout bandplan is what was most of the industry began to adopt. Personally, all my stuff is setup via the Icom band plan…but my radios also don’t use channel numbers but channel names. i.e. Ch 15 = “550”, Ch 16 = “575”, Ch 17 = “600”, Ch 18 = “625”, Ch 19 = “650”, Ch 20 = “675”, Ch 21 = “700”, & Ch 22 = “725”. Granted, if you’ve been building and using GMRS repeaters since before repeater capable radios were mainstream available to the general public…you probably don’t go by the modern (Talkabout) band plan either.