Direct from the Spectrum websitehttp://www.spektrumrc.com/Articles/...?ArticleID=1811
Attention AR7100 and AR7100R owners
We have received three reports of antennas wires detaching from the main receiver. Because the AR7100 utilizes one or optionally two remotely mounted receivers in most cases the user won’t realize the main antenna is detached. In some cases a slight “tail twitching” may be noticed as the antenna intermittently make contact however in many cases the issue may not be detected. It’s important to do the following check to verify that your antenna is properly connected.