VOLUME 8, CENTRAL EUROPE
There are 35 separate volumes covering all areas of the world.
Predictions are for minimum and maximum sunspot periods. Some of the
more common terms are:
MUF (Maximum Usable Frequency): The highest frequency which is
expected to be completely reflected from the ionosphere on at least
50 percent of the days of the month.
FOT (Optimum Traffic Frequency): The highest frequency that will be
reflected from the ionosphere on at least 90 percent of the days of
the month.
LUF (Lowest Usable Frequency): The lowest frequency that will
be
reflected from the ionosphere on at least 90 percent of the days
of
the month. When there is no frequency that will provide at least
90
percent reliability, the LUF will be listed followed by a letter
to
represent the reliability.
B
=
80 to 89 percent reliability
C
=
60 to 79 percent reliability
D
=
40 to 59 percent reliability
E
=
20 to 39 percent reliability
F
=
Less than 20 percent reliability
The volumes cover
six two-month periods: January-February, March-
April,
May-June,
July-August,
September-October,
and
November-
December.
There is a chart that covers each two-month period listing the FOT
and MUF over a 24 hour period. Additional charts list the LUF over a
24 hour period. The charts cover the following distances: 100, 250,
500, 750, 1,000 and 1500 tiles.
Predictions are given for sunspot
minimum and sunspot maximum.
The LUF charts are prepared for the
following antenna types:
Half-wave horizontal dipole thirty-three feet high.
Half-wave horizontal dipole sixty-six feet high.
Fifteen foot vertical whip.
Thirty-two foot whip.
Sloping long wire.
Inverted vee.
Other antenna types are listed, but this subcourse covers only those
antennas that are considered practical from a field point of view.
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