​​​​​​ Red wire is a voltage probe for telemetry.

thank you

Can you buy the ELRS version and add the 4in1 module? Or is it just one or the other?

Do you need any special servo or ESC to get the most out of the ELRS protocol? Iirc sanwa and futabas you need to use their higher end Rx and servos that support their fastest response times?

You can change modules.

If you want to use higher servo refresh rate, you'll need a servo etc that supports it.

Price it out when I bought mine it would have been cheaper to buy the 4-in-1 radio, and then add the ELRS module. Additionally the external ELRS can output up to 1 Watt, as compared to 250 mW with the internal. With that said, driving line of sight you'll never need that much power.

The radio comes with the module adapter, so you can go both ways. I'd go for the module you want to use long-term as your internal module unless you really need >250mW on ELRS. I personally went ELRS internally as I'm primarily installing new ELRS receivers ( I already own compatible 4-in-1 and ELRS external modules)

You do need 400Hz compatible servos to get the most out of ELRS in terms of speed, 333Hz is also supported. Same for ESC's for fastest response (since surface ESC's right now don't seem to support the DShot protocols for fastest response)

Nothing unusual for range (and in fact when pushing range you will end up turning things down to 50Hz anyways which pretty much every servo supports.

One of my fears has become reality.
EdgeTX v2.10.0-RC1 has been released, but MT12 (Surface Radio) has been removed from the companion.
It seems that there are no plans to add it in the future, mainly due to the simulator.

It's unfortunate, but there is almost no actual damage. Just back up the SD card directly. That's what we're already doing.

Where do you see "no plans to add it in the future"?

The issue tracker for 2.10-RC1 => RC2 states this:

• No companion support for RadioMaster MT12 - ETA uncertain

See RCG Forum, #6815 onwards.

I'm going to follow the actual dev release information and what the devs have said. There's nothing in the release notes that states companion support has been dropped for the MT12.

Just means it’s lower on the priority list. They’ll get to it.

Is there any good YouTubers or blogs to follow of someone that is using this radio. I'm very interested in it but most of the content I find is FPV guys saying this is going to "destroy" other brands and stuff like that. Is there a good reddit? I'd like to see more examples of how this is bringing something new to the surface market.

I just found about this thing today, was very intrigued initially, but then after reading the thread realised I'd rather have a standard mid-high range Futaba or Sanwa. Note, I currently use a GT5 but feel like I could benefit from a faster/more precise/more consistent radio.

IMO all the stuff people are raving about is mostly irrelevant in the surface world.

Need a bunch of channels and decent range, cheap? Plenty of options on the market, some with good mix capabilities.

Racers in particular don't want the hassle of complex programming, flashing, blooping and bleeping. A good trigger and wheel feel with adjustable curves and that's it. No more, no less.

And the more... ehm... out there ideas like a button to go THE FASTEREST!!!1 are possible with existing radios to a certain extent. Depends on the ESC, some can use a 3rd channel to control a variable, e.g. popular for on the fly drag brake adjustment in crawling. Nothing revolutionary.

Driver assists like limiting throttle depending on steering and vice versa - stability programs exist for surface RCs, they work good, are adjustable and once you learn how to drive well you'll turn them off.

So seems to me the folks most excited about this are the ones already familiar with the system in its air applications... but not necessarily into RC car/truck/buggy racing. Or even understanding the appeal of it.

Just my 2¢.

The price is decent though.

Joshua Bardwell has a few really good videos about the MT12 and a couple of step through videos on doing some setup.
https://www.youtube.com/@JoshuaBardwell

Radiomaster has their own YT channel with lots of howto videos about the radio. If you search "radiomaster MT12" on YT you'll get some decent review/info videos.

You nailed it. It’s FPV interest in the surface market primarily, and for them it’s a cheap way to get a good radio since they likely don’t have a decent surface radio yet. As much as I’d like to try it, I’ll probably only do that if they come out with a new improved version as others have hinted that RM likes to do with their air models. We’ll see. The cheap receivers are about the only benefit I can see to racing. Custom audible alarms would be cool, too, but not worth the money to swap and/or experiment. The sensors may in fact be more robust but that really doesn’t become much of an issue for racers - gear gets swapped out often enough that the wear & tear isn’t much to be worried about. The range and other available options like what Bardwell showed are definitely cool for the bashing type side of the hobby. I’m sure crawlers might find it beneficial for the joystick or whatever, too.