I am working on a conventional vhf taxi system in Asheville. They are narrow fm. I set my EXPERT modulation setting to NFM and saved the settings individually for each input and out channel in the system. (the system is WQCB664) The modulation still sounds like a furry little chipmunk. Someone please let fumblefingers know if I have missed a step in my settings, or perhaps I am trying to listen to some type of encrypted system. I can't locate any specific information in files other than 'conventional'.