We are getting way more than 60 miles, that was just me testing from a job site. Our distance is limited to line of site for the most part, 5 kHz would not gain us much of anything.
IMHO if you are in fact getting 60 miles off a handheld 5 watt transmitter that is programmed for NB then you have an exceptional system. I'm not saying it isn't true as I don't know your setup, location, etc.. but, if that is really true.... then 5 kh WB would in fact gain you approx a 8% increase in area coverage.... In most of the frequency spectrum by going NB it can cost you between 6-12% coverage capabilities...
To many people (including FCC) have the misconception that by going NB you gain so so so much more, but the actuality of it is, by doing so, you only gain a few more frequencies to use and that's it.....
I myself would never encourage the use of NB for a repeater system if one is trying to cover a very large (30 miles or more) area but would encourage it for in city coverage if it were for cities of a major population and after it's been proven all frequencies were in use and no other options were available....
Now if you want better use of the spectrum, do Digital....not NB....
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William R Howell, WQYX489
USGRMS Repeater & Users Group Association, CEO