ok so ive been licensed for about 3 months now, general class, and i keep second guessing myself on 40 meters. like i know theres a portion thats phone and a portion thats CW but i cant figure out if the band edge thing is just a guideline or if i can actually transmit right up to like 7.125 or whatever the cutoff is supposed to be. my elmer told me to stay away from band edges but didnt really explain why other than saying "just dont do it." is there like an actual rule about this or is it more of a courtesy thing? also does the suppressed carrier frequency count or the actual signal edges because im running SSB and someone told me the rules care about the carrier not where your signal actually is and im not totally sure what that means

so the short version is yes the rules technically talk about the carrier frequency for SSB, which means if youre running LSB and you park your dial at 7.125 your actual signal energy is going to be below that, potentially into territory you're not supposed to be in as a general. the FCC part 97 rules specify your assigned frequency which for SSB is that suppressed carrier point, but the practical issue is your radio isnt perfect and neither is mine, so operating right at a band edge means some of your signal could splash outside your privileges or outside the amateur band entirely. thats why your elmer said stay away from them. its not like theres a cop watching but you dont want to be the guy causing interference outside the band or into a tech-only segment. id just stay a few khz inside whatever the edge is and you wont have to worry about it

yeah this confused me too when i was studying for general. what helped me was just pulling up the ARRL band plan chart and looking at it while i was on the air for the first few weeks. the one thing i'd add is that on 40m specifically you also have to watch out because the phone portion for generals starts at 7.175 not 7.125 -- 7.125 to 7.175 is still phone but thats extra class only i think? or wait maybe im getting that wrong, someone correct me if so. point is theres multiple edges to think about not just the bottom of the band. i just set a mental note to not go below 7.200 for a while until i really had it memorized and that kept me out of trouble