My brand new Hitec Micro 05S receiver needs a single conversion crystal and so I went to my LHS and got a dual (because I didn't realize the Micro needed a single) . When I brought back the crystal for exchange ( somewhat iffy proposition given it is an electrical part) luckily it was unopened and he allowed me to exchange it for the only Hitec single conversion crystal he had. Unfortunately it is a channel 20 and my transmitter is a channel 24. I thought it would be a simple matter to install a # 20 transmitter crystal in my Focus 4 but apparently it is not. It doesn't matter because the plane it is going in hasn't been built yet. I just wish I had a more comprehensive understanding of the differences between all the different radio configurations since I do not have the money to buy a new radio every time I want to build a Slow Stick. I get info that Futaba and Hitec are compatible somehow and there are different shifts and Airtonics is like an entity unto itself and everybody in these parts will turn their nose up at you if you don't own a JR! Sorry , I am poor, but I would like to pass along my passion for aviation to my daughter so we have a hobby we can share. I can't even afford the $108.00 a year that it takes to join the local club. I can't do control line because the medication I have to take makes me dizzy in 2 turns. [&o]