looking for a an spectrum DSM modual for my Futaba 3pj computer radio But Could not find any , so I found on line a Corona 2.4 DSSS modual and RX system(CT3F) for 40 dollars.an extra RX for 15 dollars. the compatibility list they had for futaba radios were _ 3pm,3pk,7u,8u,8j,9c,9z,and FN Series.(mine was not on their). So I took a chance after reading a post some were a person tried it in his futaba 3PJ,and worked. so I ordered one ,when it arrived I got the radio read the instructions.Put the modual in the back and line up the 5 pins,perfect fit (click in perfect),then said switch to ppm from pcm, bind and go. "wala", it worked all 3 channels,,Well I thought for awhile scratching my head and said my old(AM) magnum senior FP-3PG 3 channel Radio that has those same 5 pins in the back with a modual (little bigger than the 3PJ),and this is not a computer radio,, so I slid on the corona 2.4ghz modual on the pins.it fit on great, but it was shifted to the lower right corner, turn on the radio and the Rx and binded them again. "Wala" It worked. all 3 channels But I didn't like the fit, I could of put foam on the other 2 sides to keep it tight in the corner. But instead I used the old box modual and the inners electronics of the corona. I still have to do a range check and put it through its paces before I put in my boat. Ill Put it in a junk RC truck first.