Hi, you are going to have a problem with that transmitter. PPM is a pulse modulation, generally found with rc planes, and helicopters. THe rx looks like its compatable, however, as stated by the ebay seller, he was using it with a rc helicopter. On such, the throttle stick has no self centring action, ( assuming its also a mode 2, uk spec, throttle on the left stick) with a rc helicopter, you have to be able to maintain throttle (headspeed) without needing constant pressure on the stick, so essentailly you can take your hand off the stick and it stays there. With a rc boat or car, the throttle needs to self centre, take your hand off the stick, it returns to centre (and stops!)
Generally, they also have a ratchet effect on the throttle stick. It should work, and some may come back and say it does not matter, but if you inadvertantly knock that stick, off goes the boat! I would not use it, it didnt cost you much, so put it down to a bad experience. Now, in the pic of the tx both sticks are central, he has taken a very clever picture!! If both stick have self centring he could not have been using it for a helicopter, as the heli gyro will not set unless the stick is all the way down, its a safety thing, so the blades dont start spinning when your face is next to them
