[ppnvedado]

 I want to use oplink in data+control. does anyone know where I can find an empty JR transmitter case (sorry it´s module) to put in it BEC+oplink+bluetooth transmitter?
Can´t find any on the web.

[TheOtherCliff]

You actually would need a full transmitter with everything except the transmit module.

They sell trainer boxes, "buddy boxes" that are basic transmitters without a transmit module.  I don't know about JR brand.  It doesn't have to be JR unless you specifically want that?

You might look for a used transmitter on eBay.

The transmitter you get needs to output PPM.  Most "buddy boxes" do.  Some transmitters don't output PPM in the module bay; for instance PCM transmitters, but most transmitters that can act as a generic buddy box at least have a port that outputs PPM.  For instance, I am pretty sure at least Futaba trainer port puts out PPM even if the module bay signal puts out PCM.

One last thing to research.  I know that the PPM RF signal polarity of JR is opposite of Futaba.  It is possible that the electrical PPM signal polarity is also opposite.  I would research about this before building.

Then there is the relay box concept.  You use a normal RC transmitter and make a box with a normal RC receiver (PPM) and an OpLink in it.  The receiver receives the regular RC signal and converts it to PPM for the OpLink.  The OpLink sends the OpLink signal out to the aircraft.

[f5soh]

Use Google with "JR module case" keywords ?

First answer: http://www.flytron.com/rc-electronics/247-jr-module-case.html
Second answer: https://www.amazon.com/Spektrum-Integrated-Case-JR-Compatible-Module/dp/B003694QUC
... : https://alofthobbies.com/frsky-djt-empty-case.html

** There is no polarity issues with JR compatible transmitters.

[ppnvedado]

sorry, english is not my language, so sometimes I have errors trying to explain myself.

It´s a empty transmitter module. Sorry again.
I'll change the topic name.

thank you both, I did look for the empty case several times and never find empty cases, maybe because I'm new in this and not using the right search words (terminology)

Problem solved thanks again for the info and for been patient with the new ones.

TheOthelCliff: very good info.
f5soh: very good links.

[Brian]

I use one of these, and it works very well: https://www.thingiverse.com/thing:585245

[ppnvedado]

thanks Brian