The antenna is often just the exposed wire portion of the wire. The wire inside the insulation is just wire. If you trim an antenna wire, you are likely trimming the antenna portion itself...not a good thing. I am not familiar with either of your systems, but this is the case with most currently available receivers I've seen.

Often, loosing signal for a moment is actually a sign of a receiver brown out (or glitch). Some servos can draw so much power through the receiver that there will not be enough current left to power the receiver itself. You can install either a glitch buster or a BEC system to help with this problem.