Dan KL7Y Said:
I tried testing this back in the '80s and never saw any significant
difference between the low end and the top end of the 160m band on a
transauroral path.
Thomas KN4LF Says:
Whether at 1800 kc or 2000 kc, either part of the band is still to
close to the electron gyrofrequency, which is the naturally occuring
frequency of maximum signal absorption, to make any appreciable
difference. Gyrofrequencies on polar auroral paths from the U.S. can
range from around 1550 kc to as high as 1750 kc, maybe higher?
I began my radio interest in the mid 1960's as a broadcast band dxer
and have spent many years studying the band. Ironically I too have
observed European broadcast band stations making it through the polar
auroral zone, when the transmit frequency was far enough removed from
the path of maximum gyro frequency absorption at that given moment,
while at the same time 160 meter signals weren't.
Most of the mysteries of 160 meter propagation are explained by N4XX
Ted Cohen's co-authored articles in CQ magazine in March and April 1998.
His articles can be found on my 160 meter band website at
http://kn4lf.tripod.com
Take Care,
Thomas Giella, KN4LF
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