The interference path is not through the receiver, the long wires between receiver and servos are the right length to be antennas, the wiring picks up ignition leakage from the ignition system, which happens to be between 0-20KHz, the same frequency (range) as the servo signal wire lead.to the servo amplifier (the servo signal is narrower, but includes the ignition range). Any ignition wiring or components HAVE to be at least six inches (more is better) apart from flight control system wiring or components. The particular radio frequency is not a factor. Ignition interference servo hard overs can affect 27, 50, 72, 75 mhz, AND 2.4 GHZ radios alike. They all use the original servo signal system developed many decades ago. Receiver battery packs too close to ignition components (like switches) can cause interference also.
Twisted servo wiring is effective in damping or attenuating outside interference, you can buy servos with twisted leads. When we changed to 2.4 GHZ I thought the interference issues were over, I was flying electrics and sailplanes at the time, when I put 2.4 GHZ radios into my gas powered warbirds, the interference problem came back. When I took a look at the issue I thought I had solved, I found I had forgotten my lessons, throttle servo wiring in the same bundle with ignition leads.
Last edited by sjhanc; 05-23-2020 at 03:35 PM.