RE: Single VS Dual Conversion RX's & Interference
The problem with SC receivers is the image frequency. As pointed out in an above post, JR gets around this by not offering a receiver where the image frequency is likely a problem. A single conversion receiver is cheaper to make and lighter. Berg,FMA and others contain circuitry that will reject transmissions that are not of the correct signature. However if the image frequency is there it will activate the automatic gain control and reduce the receiver sensitivity.
In the final anaylsis the dual conversion receiver is the best overall way to do it. Yes there are more crystals in one than the SC receiver. In the five years I served as the factory rep for Kraft and Logictrol I never saw a bad crystal that wasn't caused by a crash.
I dumbthumbed a Pitts full bore special straight into the concrete. I broke the crakshaft, ignition module, the receiver and totaled the aircraft. All three crystals and the ceramic IF filters were intact but the receiver didn't work.