More to it than just swr..A low # is nice though... It also depends on type of ant,where its mounted and what to...Coax type and how well it was put together n such.. But yeah 10-20 mi is easily possible.. Hell qrt does hundreds or more on less.. Done it myself..
How far you transmit is inversely proportional to the amount of distortion in your signal and directly proportional to how far I can hear. Lots of other factors but those are the two main ones.
Make sure you turn the power all the way up when using the radio to check swr. My 655’s meter does show less swr than my MFJ Antenna Analyzer. If my meter on the radio says 1.5 then the mfj is reading probably roughly a 2.2.
Also I’m still working on getting my ohms to 50 and a good swr. The power meter definitely acts better when my ohms are right.
Mfj only uses maybe a 1/4 of a watt...If swr climbs any amount with power then you have an issue with antenna be it what your useing and where its mounted..Now again coax,is it cheap trk stop stuff,was it crimped or soldered and was it dont correctly...A multi meter will help..
This is tooooo toooo funny ... You are wrong. it don't matter if it is one watt or a thousand watts. if you have issues with an swr indication changing when your power increases, then there are other issues with your feedline (coax) and your antenna ground (RF ground) ---->> generally this can indicate common mode current issues. You are on the right track, see my above comment.
To suggest the strength of the signal has no relevance on whether someone can hear it or not, or how well it can be heard is hilarious.
