[Al Skierkiewicz]

Jerimiah,
I checked the Quad Cities listings and unfortunately for you Channel 4 is likely causing the interference. They may have changed transmitters or they might have a transmission problem. Although the band in which the VEX controller is designed (75MHz) is supposed to be protected it is close enough to channel 4 to be a possible problem. Channel 4 has a channel edge 4.75 MHz above the carrier of 67.25 or 72MHz. If they are having a problem with their output color filter there would be a out of band carrier 3.58 MHz above that which makes it right in the center of the VEX Band. Do you know where the channel 4 transmitter is in relation to your house? I know that channel 8 is in East Moline but I am not familiar with the other transmitter sites.

If you have cable running through the backyard, especially above ground, the critters may have eaten through the coax and it is now radiating cable signals. Since cable is not intended to radiate, it can and does have signals throughout the band including the protected space between TV channel 4 and 5. You can check this if you have a portable TV. Take it out in the yard with a whip antenna and see if you can pick up cable signals. If you can, the cable company is required by the FCC to come and correct the problem. Under FCC rules, there may be no stray energy radiated by the cable system. Even if you were to purchase the alternate crystal kits, they all appear to be in the 75MHz band.
I am not aware of any military equipment operating in this band, that also may be a possibility if you are near a base. That I cannot help you with.

Since I haven't really been close to VEX this year, I can't remember this part. Doesn't VEX have a tether? Does the robot repsond the same way with the tether?