Chris,
I had the same problem with one of my planes. Here is what I did. I could not really move things around without too much of an effort.
1. Try and locate the problem. Is the noise there always, or is it only there when all servos are plugged in? Unplug them one by one at the receiver and see what happens. (Sometimes vibration makes a bad connection worst)
2.take the antenna out of the plane (that is if it's in the plane) have someone change the antenna orientation as you stand where the glitches start.
(It might be that you are close to something within the plane)
3. Put ferrite beads on the extension wires close to the receiver. (About one inch)
4. Twist the extension wires and then put ferrite beads on.
5. Move everything as far away from the Ignition unit, it's cables and it's battery as possible.
6. Check that the Ignition wires don’t rub against anything e.g. the exhaust.
7. Check all switches for bad connections (bypass them)
I will stand by the saying, that rcexl. Ignitions are very well shielded, I think that your problem is vibration at some connection?
Andreas