X20 vs TBS MPM

[Konrad]

I just spent 90 minutes with Ethos thanks to my RC student. Basic system set up and a simple 5 servo trainer setup. Really stating to like Ethos. Thinking I may need a tray radio with Ethos (hint).

Now my student wanted to use some Horizon Hobbies RF products. This means that he bought a TBS MPM to use DSMX RF protocols. Much to my surprised this TBS micro RF module (non-JR module) does not fit the rear receptacle found on the back of the X20.

For some unknown reason FrSky has set the receptacle with a high wall on three sides. This wall results in cavity being 1.4mm too deep so that the TBS module can't engage with the holding rails or the electrical pins. The MPM doesn't mechanically fit the body of the X20. I didn't check to see if Ethos will allow for the integration with TBS MPM.

As a result of this mechanical issue with the X20 rear module bay I'm now the owner of a TBS microMPM that fits my X-lite (running OpenTX). Now the fun begins getting all the firmware up to date.

 

[Konrad]

Now that I own a TBS MPM I was shocked that there is no documentation with it. Also there is NO FCC ID attached nor is there any identification as to the manufacture other than a stylized sheep's head. I see where the retailer says that one might need a Ham license to operate these modules. I'll have to look it up but I don't think a Ham license give you any privileges on the 2.4 gHz band.

This MPM really is looking like a FUBAR product!

 

[Chris]

I would have just sanded the back of the radio... Or at least looked into it VERY heavily...
I had not heard about this yet though. Interesting...

 

[MikeB]

I have 4, "Lite" modules (2*XJT, a ELRS and URUAV MPM) and they all fit my X20, X9LiteS and X-Lite, so I would suggest the problem is with the mechanics of the TBM module.

ETHOS doesn't support the MPM, but erskyTx for the X20 does (and may be installed as a "Dual Boot" system alongside ETHOS).

Mike

 

[Konrad]

I would have just sanded the back of the radio... Or at least looked into it VERY heavily...
I had not heard about this yet though. Interesting...

I was thinking of that. But the radio X20 is not mine. Besides taking off 1/16" may likely sand through the wall making the back module bay rather flexible! I told my student with the money he saved from the purchase of the X20 off of Aloft's classified section, he can buy a genuine Spektrum TX if he really wants to fly that inferior tech. Or barrow my DX9 (I don't know why I won't sell him my radio). I gave him a few pennies on the dollar for the MPM as it fits my X-lite.

 

[Konrad]

I have 4, "Lite" modules (2*XJT, a ELRS and URUAV MPM) and they all fit my X20, X9LiteS and X-Lite, so I would suggest the problem is with the mechanics of the TBM module.

ETHOS doesn't support the MPM, but erskyTx for the X20 does (and may be installed as a "Dual Boot" system alongside ETHOS).

Mike

I assume these are all FrSky module cases. This is looking like a deliberate attempt by FrSky to keep non-FrSky approved modules off the X20.

From a corporate perspective I understand that. But from a customer perspective having custom non-standardized hardware is unacceptable. Now the question is FrSky's µRF Bay an industry standard. It is not! I have to smile at myself seeing how FrSky locked out the secondary OEM modules while allowing their modules to be backwards compatible with their earlier X-lite configuration.

When I get an Ethos radio I'll have to look into the ersky option to run Spektrum RF protocols.

 

[MikeB]

I would still question the TBS mechanics. All the Lite modules I have fit BETWEEN the the raised border, so the border could be much higher and they would still fit.
The border (you describe as 1.4mm too high) on my X20 is 8mm high, on my X9LiteS it is 13mm high. I note the X-lite has no border.

Mike

 

[Konrad]

It is definitely a mechanical issue with MPM body and the bay wall (border). I can see that the MPM body rests on the border before the locking rails even make contact. As the MPM body has a large radius the distance between the walls will change the effective clearance between the module body and the bay. The electrical pins and locking rails of the MPM fit just fine, as they fit the FrSky X-Lite TX (non-walled bay) just fine.

But as you say Ethos doesn't support the MPM, this really is just an academic exercise.

P.S.
The TBS module off set is only 6mm. So my 1.4mm spec might be a bit short.

 

[thenated0g]

could you just make a extension cable to mate the x20 to it?

 

[Konrad]

That would start to look like many of the early 72mHz to 2.4gHz conversions of old. Cables are prone to loosing connection and are cumbersome. Then we still have the issue that the programing power of the X20 (Ethos) isn't available.

 

[MikeB]

Looking around, I see there is an adapter available from TBS to allow the TBS MPM to be fitted to the X9Lite. This should allow the module to fit to the X20 as well.

Mike

 

[Konrad]

Gotta link?

I've seen an older X-Lite to JR module adapter. I have no reason to think this will work with the newer FrSky deep pocket RF bay.I haven't seen a FrSky X-lite bay (X20 deep bay) to TBS lite MPM adaptor. But that might just be my poor Google Foo (skills).

 

[MikeB]

On this page: https://www.team-blacksheep.com/products/prod:tbs_mpm
at the bottom under "Customize it"
Add X9 Lite adapterMore (+ US$ 6.95)
Click on the "More" for details.

Mike

 

[Konrad]

THANK YOU!

Now it is down to loading your ersky TX program

 

[jseyfert3]

I see where the retailer says that one might need a Ham license to operate these modules. I'll have to look it up but I don't think a Ham license give you any privileges on the 2.4 gHz band.

As a licensed (but non-operating) ham, I looked it up. Hams are primary users of the 2.4 GHz band, everyone else is actually secondary users (WiFi, RC, etc). Range of frequency allocation for hams is 2.390 to 2.417, allowed power up to 1500 watts PEP, same as most other ham radio allocations. But I saw one reference that said they cannot use spread spectrum (which is all commercial 2.4 GHz RC usage), and the transmission must contain the ham radio license identification, like any other ham usage (must identify each transmission plus at least every ten minutes on transmissions over 10 minutes in length). The identification can take many forms, for example on video transmissions you can overlay your callsign on the video stream, but a plug and play RC module probably doesn't have ham radio callsign identification built in...

 

[Konrad]

Thanks

So as I suspected the notice on GetFVP sales page is in error and misleading!