As I have never had to run a long lead before for a servo I have a question. I will have to run two leads from the tail of the jet to the receiver both which will have to be ~800 to 900mm. I see that there are "buffer" leads. Is there a set rule when to use a buffered lead?

Oh, by the way, this is in a Spectre for the elevator and rudder.

What I heard was that the "buffer" changes the way the electrons flow such that the long lead will not act as an interference antenae. Sounds ok to me, but I've never known for sure. Hope someone can give a better explanation. Good Question!

I have run 48" extensions to digital servo's in tails with zero problems. I make the extensions myself.

I have run up to 48+6=54 inches of HD leads to a digital servo using 5 cells and a JR 940 or 955 Rx with no problems. Just use HD quality ext and minimise connections. Try to make ONE ext from the servo to the Rx. Use Gold plated contacts for sure. Test your set up with 4 cell and five cells. If the 4 cell fails, you may need amps in the ext.

I have a trim Spectre and have just used normal JR extension leads to both rudder and elevator servos and used 1100 ma 4.8 v battery pack. I have had about 40 flights no problems at all. When you look at the distance it is realy not much more than a lot of guys flying pattern planes run to their aileron servos.

Good luck with the Spectre it's a great plane.