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Idiomas disponibles
Idiomas disponibles
SHORT-WAVE
General
The receiver is particularly suitable for short-wave
(SW) or long-distance recep-
tion. The latter name results from the fact that the waves transmitted by a short-
wave transmitter are reflected by an ionized layer in the atmosphere (the iono-
sphere), making it possible to receive transmissions
at long distances from the
transmitter.
.
Short-waves
can be expressed
either in metres
(wavelength)
or in kHz (ke/s,
frequency). These expressions are easily interchangeable by means of the following
equation: frequency (kHz or kc/s) X wavelength (metres) = 300,000.
Examples:
Short-wave forecast
Short-wave reception depends on the hour of the day, the season ant the sunspot
number.
These three data determine
the frequency
at which
there
is the best
chance
of good
reception.
On
the chart
on
pages
20 and
21 the
reception/
transmission. areas are encircled. The tables on pages 17, 18 and 19 give the most
favourable frequency in MHz for each inter-area connection and for each area
separately. The Roman figures above the tables show the month to which the table
applies. The expected Sunspot numbers S for the years 1968 to 1974 are as follows:
1968
1969
1970 1971
1972
1973
1974
S
125
125
70
70
#70
5
5
Frequency finding
12
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