I have a similar problem with a ZDZ 80. I changed everything - receiver, battery pack. switches everything. I removed the spark plug and turned over the engine with the starter. With the spark plug out in the open and sparking away there was no interference with the receiver.
I installed a PCM receiver and am not comfortable with that solution even though I now have twice the range with the engine running than than I had with an FM receiver with the engine not running. There is still something there that is causing radio interference. PCM gets around it but it still should be fixed.
I am wondering if there is something in the Falcon ignition that causes interference under vibration and does not when there is no vibration.
I have a C&H ignition and will try that if I can figure out how to hook up the spark plug lead.