Salvage a genuine DSM2/DSMX module from a cheap Spektrum DX4e or DX5e transmitter, and convert it to a JR-style module for Taranis, 9XR and other transmitters. These put out between 60mW and 100mW, depending on your luck. Spektrum individually tests and marks the output power (in dBm) on the back of these modules, so you may want to open a few up and select the one with the highest output. Besides the spectrum module, you'll need about $5 of cable, 3.3V regulator and antenna. You may also want to to look at Dan Myers' similar project at http://www.thingiverse.com/thing:293608 I built this thing after looking at his (thanks, Dan, for the motivation!) because I wanted these differences: You'll need: Remove the Spektrum transmitter module from a Spektrum DX4e or DX5e transmitter. Get an antenna, cable, and 3.3V regulator. Here are sources: Cable: http://www.alofthobbies.com/rf-coax-assembly-70mm.html Antenna: http://www.alofthobbies.com/2db-module-antenna.html Regulator: http://www.ebay.com/itm/371077257166 A few small screws 4.7k resistor Diode (1N4148, 1N914 or similar) 5-pin 0.1" Dupont connector and wires Assemble. The regulator fits between two posts, and the transmitter board sits atop three posts. You'll need to carve small half-moons out one side of the Dupont connector so that the wires can exit at a right angle. For schematics and electrical hookup info, start with http://openrcforums.com/wiki/index.php/How_to_modify_your_9x_to_the_DSM_protocol You may also find useful info at: http://www.hacksmods.com/2012/07/hp6dsm-module-wired-up/ You'll need to follow a few of its links.