Does a device exist that will scan and display the most used, or least used frequency so I know what frequency to use, or not use. I have the Sennheiser G3 Wireless system and I know it has a scan function but I find it does not work that great.

If there was a device that would show me a graph of the frequencies used, I could pick one not being used. I am guessing this will improve my mic performance. Anything out there? I know one of the Shure Wireless systems has this built in one of there mics receivers.

I know one of the Shure Wireless systems has this built in one of there mics receivers.

Haven't you answered your own question?

The below device was posted on another forum, it might just be the solution.

Buy RF Explorer model WSUB1G [TES82252P] | Seeedstudio (http://www.seeedstudio.com/depot/RF-Explorer-model-WSUB1G-p-922.html)

you would not only need the frequency finder but a receiver capable of being able to tune in the frequency. Considering the variety of venues and the age of the equipment they use it could be an interesting challenge