One thing to know about skip, the higher the frequency, the less likely
you will hear it. 40mhz to 100mhz is quite common and can be heard
with approaching STRONG weather systems, magnetic storms from the
sun, and temperature inversion (which is more evident at higher elevations).
Above 100mhz is less often heard but does happen, when you get
to about 500 mhz the signals tend to go straight out into space.
The higher you go in frequency the less likely it will happen.
(the above paragraph pertains to FM transmitions, SSB transmitions
are better on skip. But since most agencies use FM, what was stated
is most likely the case).
Then you get freaks of nature that bend all the rules, but that is a
once in a blue moon effect.
Danny
n4yek@qsl.net