Re: Channels and Frequencies
8.33 freq's are presently in use above FL195, but this will soon reduce to FL95.
Under the ICAO rules, if a country has only one 8.33 freq (and the UK presently has one becoming three in March) it is declared an 8.33 khz environment and has to comply with the '6 digit spoken' rule.
I understand that the USA does not use ANY 8.33 khz freq's and is thereby exempt!
By the way, if you are using a 100khz frequency such as 118.6, there will be no change.