okay so i just upgraded to general last month and im still trying to wrap my head around the frequency allocations. like i know generals get more privileges but every chart i look at seems slightly different and i dont fully understand where the band edges are and why i shouldnt transmit right at them.

my elmer told me to stay away from the very edges of my allocation but didnt really explain why, something about filter rolloff or adjacent channel stuff? and then theres the whole thing about the ARRL band plan versus what the FCC actually says you're legally allowed to do and those arent the same thing apparently? im mostly interested in SSB on 40m, just ragchewing nothing fancy. so like 7.175 to 7.300 is where generals can do phone right, but should i just avoid the bottom of that range entirely or what

yeah your elmer is right about the edges and heres the thing that took me a while to get too -- the FCC allocation says 7.175 for the lower edge of general phone on 40m but your transmitted signal isnt just on one exact frequency. if youre doing SSB your suppressed carrier might be at 7.175 but the actual sidebands extend a few kHz above that, so if youre too close to the edge you could technically be putting energy outside your allocation without meaning to. most people just stay a few kHz inside to be safe, like dont set your dial below 7.178 or so and youre probably fine.

the ARRL band plan thing is just a gentlemens agreement basically, the FCC rules are the actual law. the band plan is more about keeping digital modes and CW and phone from stomping all over each other which it mostly works okay. for casual ragchewing on 40m phone youre gonna find most activity between 7.200 and 7.280 anyway so you wont even be near the edges most of the time

just upgraded myself a few months ago and had the exact same confusion. the chart on the ARRL website actually helped me more than the FCC part 97 tables which are kind of dense to read through. also worth knowing that 7.290 is kind of informally used for AM on 40m so if you stumble onto a bunch of AM stations down there thats why, they wont bite but it can be surprising if you dont know