I'm hoping someone can help with this. One of the VHF channels I monitor has been very noisy lately to the extent of being really annoying. I locked it out for a few days but yesterday unlocked it to see if the noise had been eliminated. The frequency is 155.50 (NYSP ComData). I activated the attenuation button (global attenuation ) and the noise went away, but sensitivity was lost on other frequencies. I got thinking about this and looked in "Program" mode and remembered that I could attenuate just that one channel. I activated attenuation through program mode and it did nothing to eliminate the noise. Is the level of attenuation different globally as opposed to individually?