Wikipedia tells me that 30-300MHz is VHF. Why do I hear that the military emergency frequency 243MHz is a “U”? Is there a difference in the spectrum naming between civil and military? Is there a history behind it?
The UHF aviation band is 225-400 MHz.
The naming of these frequency bands is arbitrary between communities, aviation UHF is not the same as ITU UHF not IEEE UHF, they are all different.
Thank you, that makes sense.
Apropos of nothing, but it seems like some time ago, we ran out of superlatives to describe frequencies. The naming was already getting a bit silly with “ultra high frequency”, but then SHF (super high frequency) and EHF (extremely high frequency) were added almost as “whoops, we used ultra too soon, now we have to think of something else”. I was hoping once the terahertz bands became practical, the next frequency band would be AHF for “absurdly high frequency”, but instead it got called THF for “Tremendously high frequency”.
Followed by RHF – Ridiculously High Frequency, and LHF – Ludicrously High Frequency.
Cheers for the great reference, Cobalt! 
Great Cobalt :)
