[BC] clear channel stations

[PeterH5322]

 >I seem to remember that 700 and 1200 were the only stations at one time with
 >no other US mainland stations on at night???
 >
 >How long ago was that?

About 1989. Perhaps a bit earlier.

Remember, US Class I-A Clears always could be used in Hawaii. Canadian
Class I-A Clears as well, in Hawaii, or anywhere else in the US, provide
the station was at least 650 miles distant from any point in Canada.

Then Alaska was allowed to use US Class I-A Clears, as the new Class I-N
Clears (allowed only outside the 48 states, and required only to meet
Class B efficiency minimums).

Finally, all US Class I-A Clears were allowed within the 48 states.
Mexican Class I-A Clears as well, in Alaska, Hawaii, and the 48 US
states, and the US territories.

About one-half of the US Class I-A clears were exempt from the Class II-A
List. These certainly included 700 and 1200, but also 640, 650,
originally 660, 750, originally 770, 820, 830, 840, 870, 1040, and 1160.

So, we have 13 original Class II-A List Clears, and the 12 supplementary
Clears, for a total of 25.