I'm new to radio, I listen quite often and trying to learn. My truck CB has been picking up a lot of DX and I notice I only hear 3 digit call signs, when I try to ask someone how they got a 3 digit call sign they ask me what I mean, then they never respond? I'm thinking they might realize their bleeding onto 11 meter and tighten their bandwidth, but they never have had the courtesy to explain before doing so. And besides can't you DX on 11 Meter with all the solar flux going on?