I just started to play RC planes again after 4 years leaving it behind. Anyway recently, I bought a cheap 27 mhz AM RTF plane, everything is fine except for the radio system. ya I know cheap ones.... but I managed to fly it 2 times before it crashed, and now it's fully repaired. The problem was just the radio system, after it went more than 200ft away the radio starts to get interference. I checked the electronics and found out that the Tx crystal doesnt match the Rx crystal! The Tx is 27.277 mhz and the Rx is 26.722 mhz. I'm just wondering how the radio system could still work even with different crystals. I need some advice on wether to change the crystals and match them or not, or is there some other way to improve my reception electronically? I am looking forward to buy a new radio system but I just don't want that plane to be a waste.