organic analysis of FD radio systems

usa

in the beginning all Fds were on ? 10 ? shortwave radio channels - maybe 1920

then countywide system sprung up on 33 mhz and 46 mhz - with most
larger cities and many suburbs on the 154 mhz band

then 450 mhz was added

then 800 mhz was added

the 700 mhz was added

now - most major cities use 800T - with some simplex FG channels on
800 mhz or 700 mhz

suburbs use all the bands

rural areas mostly use 154 mhz and UHF now - very few agencies remain
on 33 mhz or 46 mhz

many counties have 1 uhf or vhf channel for countywide dispatch of all
fire and ems units

fireground channels might be done on countywide FG channels or on
'local channels'

some states have statewide trunking systems - some do not - relatively
very few FDs use these statewide TRS - TRS can be on VHF high or UHF
or 700/800