The reason for the post was we just moved our shop location, and have been experiencing unexplained severe communication problems. We found there was a 900 MHZ shop system
cordless phone station less than 100 feet away. It also seems the problem gets worse the closer we get to the cordless phone station. It was really quite dramatic - If we started the robot from one side of the field it went about 20 feet, and than as it got a certain distance closer to the cordless base station it slammed to a stop, the no signal light turning a solid red.

(We are also about 1/2 mile from an active runway, emergency medical/police stqation, etc.) TOO many possible sources of inteference. It seems that the older radios (2001 vintage) may be more sensitive.

On the Bright side, the high frequency TIG welders and regular cell phones don't seem to be a problem ;-) Also from past experience - putting the reciever antenna closer than a foot to a sparking drill motor is probably a bad idea.