ok so ive been licensed for about 3 months now and i upgraded to general last month and im still kind of lost on the whole frequency thing. like i know there are portions of 40m i can use now that i couldnt before but every chart i find online seems to show it slightly differently and one of them said something about "band edges" being dangerous to operate near and i dont really understand what that means

like is 7.125 safe to use for SSB? and whats the deal with the phone/data portions, is there a hard line or is it more of a suggested thing? i dont wanna step on anyone or worse transmit where im not supposed to as a general. my elmer kind of glossed over this part

the band edge thing is real and worth paying attention to. basically the issue is that your radio's displayed frequency is the carrier frequency but with SSB your signal actually extends several kHz above (for USB) or below (LSB) that depending on your sideband. so on 40m where everyone uses LSB, if you tune to say 7.125 your actual signal occupies maybe down to around 7.122 or so. if you tuned right to 7.125 which is already near the lower end of the general phone allocation you could theoretically have part of your signal stepping into the tech/novice or even CW portion depending on what you mean by "near"

the FCC allocations are the actual legal lines, the ARRL band plan inside that is more of a gentlemens agreement kind of thing. for 40m generals get phone starting at 7.175 up to 7.300 if i remember right. 7.125 to 7.175 is still extra class territory on phone. so yeah 7.125 for SSB as a general would be a problem, you'd want to be at 7.175 and honestly id stay a few kHz above that just to be safe with the sideband thing

yeah same thing tripped me up when i first got general. what helped me was just downloading the arrl band plan chart and printing it out and keeping it near the radio for a while. the fcc part 97 stuff is what you legally have to follow, the band plan stuff within that is basically what the community agreed on to keep things organized

also worth knowing that some of those lines shift for ITU regions, like 40m is actually different in europe vs here so if you're working DX the other station might be operating somewhere that looks weird to you but is totally fine on their end