Woody,
Crashmaster is correct in stateing 'no coiled wire' inside the fuse. Always have as much outside the fuse as possible unless you use a tube to run it thru. Also, your instructor probably knows this (but 2-sets of eyes are better than one) on the 'buddy box' system, I always make sure the radio YOU are using (the buddy box) has NO BATTERY and/or the POWER IS TURNED OFF. The radio the instructor is using should be the only one with a battery. This prevents accidental interference from the two fighting each other.

Fly high......in the air, that is.....