I got this one a while back on eBay I bought it for the trex 150 but never used it. Here is the seller I got this one from but it was only $14 then.
https://www.ebay.com/itm/R111XN-DSM2-DSMX-Micro-Satellite-Receiver-1-4-Grams-Up-To-12-Ch-Sat-/291957498912?_trksid=p2349624.m46890.l49292