This explain why. I'm using 18ga servo extensions twisted 60" long into the booms of my boomerang Xl with no filter. 50 + fligth not a single glicth. Text copy from TBM.


Note on twisted extensions: If you are still using 72 or 50 MHz transmitters instead of the new 2.4 GHz or Spread Spektrum technology, twisted wires are suggested. If you are using the new technology, twisted wires offer no advantage to untwisted wires. Twisting extensions eliminates interference caused by stray signals being picked up by the signal wire in the old MHz systems. The wire can act like an antenna. This is rarely a problem, but if you have an intermittent interference problem this may be the cause. The signal wire (usually orange or white in color) has little current running through it. It tells the servo what position it needs to be at. The red and black wires have higher current in them as they provide power to the servo. Only the signal wire will pick up stray signals due to the low current. Twisting the wires in effect wraps the signal wire around the power wires which cancels out electrical noise. The noise is called electro-magnetic interference, abbreviated to "EMI". Typically extensions which are around 3' long cause more problems because they are the length of a receiver antenna, but extensions of any length near a gasoline (spark) engine ignition system can pick up EMI from the engine's ignition. DA, 3W, ZDZ, and other ignitions are now shielded so well that this is rarely a problem. Also, resistor sparkplugs are used which keep EMI down. For these reasons, we offer only twisted wires.

Alejandro