ok so i just got my general ticket a few weeks ago and ive been trying to figure out where exactly i can operate on 40 meters. i know theres a difference between what the FCC allocates and what the band plan says but honestly the more i read about it the more confused i get. like is the band plan actually a rule or is it just a suggestion? and i keep seeing stuff about staying away from band edges but nobody really explains why. i tried to get on around 7.125 the other night for a SSB contact and some guy came on and said i was too close to the edge but 7.125 is still within the general portion so i dont really understand what the problem was

yeah this trips up a lot of newly licensed folks, the short version is the FCC allocation is the actual legal limit and the band plan is more of a gentlemans agreement that the amateur community uses to keep things organized so nobody steps on each other too much. youre not going to get fined for operating SSB at say 7.150 even though the band plan might suggest that area for something else, but people will definitely give you grief about it on the air.

the band edge thing is a bit different though and thats actually worth paying attention to. the concern is that your signal, depending on how your rig is set up and what mode youre running, can have sidebands that extend beyond where your carrier frequency is. on SSB the suppressed carrier is what you tune to but the actual audio content goes up several kilohertz from there, so if you park your dial at 7.125 your signal might be reaching up toward 7.128 or so depending on your audio. not a huge deal in the middle of the band but at the lower edge of your allocation it matters because you could be splattering into the CW portion or into a segment you dont have privileges on. most people suggest staying at least 3 kHz or so inside any hard boundary just to be safe.

the guy who said something to you was probably just being a little territorial honestly, 7.125 is fine. that said the lower edge of the general SSB allocation on 40 is 7.175 in some band plans i think? or maybe its 7.200, i always have to look it up. anyway the point is there are segments on 40 that are extra class only and if you wander into those you could technically be operating outside your privileges which is an actual problem not just a gentlemens agreement thing. i'd just download the ARRL band plan PDF and keep it nearby for a while til it becomes second nature