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 technicians are pretty limited but now that im general i thought i could just go anywhere on the band but apparently thats not how it works? like i was listening around 7.250 and heard a bunch of phone but then someone told me generals cant operate below 7.175 or something like that. is that right? and then theres the whole thing about the band edges which i dont really understand — someone at my club said to stay away from 7.000 and 7.300 but didnt really explain why. is it just that you might accidentally transmit outside the band or is there more to it than that

yeah so the general phone allocation on 40m is 7.175 to 7.300 MHz, your friend was close but had the number slightly off. below 7.175 is extra class territory for phone. you can still operate CW and digital modes lower in the band as a general though, down to 7.025 i believe for CW.

as for band edges, the main thing people worry about is that if your rig has any drift or if youre running a sideband signal and you set your dial frequency too close to the edge, part of your actual transmitted signal can end up outside the allocation. like on LSB your signal extends a few kHz below the dial frequency so if youre sitting right at 7.175 you might be stepping on the extra-only segment. most people just stay a couple kHz inside the edge to be safe. its not a huge deal if you understand whats going on but a lot of new generals get caught out by it

dont forget there's also the ARRL band plan on top of the FCC allocations, they're two different things. the FCC stuff is what's legally required, but the band plan is more like gentlemens agreement about where to find certain modes. like around 7.040 is pretty much understood to be FT8 territory now even though thats not in any rulebook. worth downloading the ARRL band plan pdf and just keeping it handy for a while until it clicks