ok so i just upgraded to general last month and im trying to figure out where i can actually transmit on 40 meters. i know there are band edges and i know you're supposed to stay away from them but i keep reading different things. like the FCC allocation says one thing and then the ARRL band plan says something slightly different and i dont know which one actually matters legally.

also someone at my club told me to never operate within like 3 khz of the band edge because of frequency drift or something? im running an ft-891 so i dont think drift is really an issue but maybe im wrong. just want to make sure im not accidentally transmitting out of band or stepping on phone portions when im doing digital or whatever

so the short answer is the FCC allocation is the law and the ARRL band plan is just a gentlemens agreement basically. you wont get fined for operating SSB at 7.150 or whatever even if the band plan suggests something else, but you might annoy people.

the 3 khz from band edge thing your buddy mentioned is real advice though even on modern rigs. the issue isnt really drift so much as the fact that when youre on SSB your signal has bandwidth, so if you set your dial to say 7.300 your actual transmitted signal is spreading up from there depending on whether youre upper or lower sideband. you can clip the edge without even realizing it. most people just stay a few khz inside to be safe. for general on 40 phone youve got 7.175 to 7.300 if i remember right, just dont hug that 7.300 ceiling too close.

went through the same confusion when i upgraded honestly. what finally made it click for me was just downloading the ARRL band chart and keeping it next to the radio for a few weeks. after a while you just kind of know where you are. the digital stuff on 40 is generally down around 7.070-7.125 area which as a general you can get into no problem. just watch yourself near 7.125 because that bleeds into the extra/advanced phone territory and things get crowded there on weekends