Dec. 1931 / Jan. 1932 Short Wave Craft
Wax nostalgic about and learn from the history of early electronics. See articles
from Short Wave Craft,
published 1930 - 1936. All copyrights hereby acknowledged.
'Short waves,' with their ability to support long distance communications
under certain conditions, became a phenomenon in the late 1920s,
and a market developed for converting commercial broadcast receivers
to short wave receivers. Magazines at the time were full of advertisements
for the devices. The particulars of short waves and the way they
propagated in the upper atmosphere were not yet well understood
early on. In fact, the government considered transmission frequencies
above 1.5 MHz (≤200 meters)
so useless that they assigned those bands to amateur radio operators.
The presence of an electrically conductive layer, known as the
ionosphere, was not verified until 1927 by
Edward Appleton. Hams quickly investigated, experimented, and
successfully exploited the long distance radio communications possibilities
so successfully that the government quickly re-claimed most of the
bands. They were rewarded by being prohibited from engaging in transmissions
for the duration of America's involvement in World War II.
Much has been learned about the ionosphere since 1931
(the publication date of this article),
but what is printed here is still largely valid. For instance and
very importantly, the F2 layer (not identified
or named at the time of this article) which is highest layer
of the ionosphere, is maximum where the sun is directly overhead
(see numbers on this spacew.com
See part 2 in the
February / March 1932 edition of Short Wave Craft.
The Propagation of Short Waves
The author describes his new theory of the effect of cosmic
energy and change of season on the transmission and reception of
short waves. The solar radiation of electrons in their effect on
short waves is discussed.
By Robert Meyer
In the last few years, many radio listeners have tried to change
over to the reception of short waves.
Fig. 1 - Daily range-displacement of short waves.
Much success has been attained but the interest in general waned
very soon; because in the short-wave field there are peculiar propagation
conditions which, so far, have not been understood in their basic
principle. Even the set owner who is well up in the working conditions
on the well-known broadcast wavebands, is confronted by puzzles
in the case of the bands which have been investigated but little.
It is a well-known fact that the working conditions or ranges
of all the bands change once in the period of a day; but that this
change is considerably modified by the season of the year. This
observation led the writer to formulate the idea that the emission
of the short-wave transmitter is something secondary; the influencing
or modulation of a cosmic energy being probable. With this assumption,
it becomes clear that even a nearby transmitter must remain inaudible,
unless a flow of this cosmic energy is present between the sender
and the receiver.
Fig. 2 - Short wave lines of conduction over
the earth in summer.
Now it is natural that we should, in view of the cosmic dependence
of the earth on the sun, take into account the solar radiation of
electrons, to explain the formation of lines of conductivity for
short-wave transmitters. The solar electrons strike the earth and
are partially reflected; after reflection, they must describe a
curve which is determined by their own velocity and the attraction
of the earth. Fundamentally, therefore, the reflected electrons
must describe a path, through the atmosphere, from the point of
rebound to the "night side" of the of the earth (the side away from
the sun). The curve must always have the same form, since the two
effective components (velocity and attraction) do not change their
relation. If, nevertheless, the distance traversed by the electrons
varies according to the time of day, then an important factor must
have remained hitherto unconsidered.
It has been recognized, since Newton, that the reciprocal action
of two bodies in space does not take place in the true centers of
the bodies, but lies eccentrically according to the respective strengths
of the bodies. From the reconstruction of many observed zones of
reception, I now found the ideal or specific center of terrestrial
attraction displaced about half the earth's radius or 1,980 miles,
toward the north magnetic pole. The position of this center of attraction
may be seen in Fig. 1; and from this diagram there also becomes
clear its significance for the determination of reception zones.
The reflection curves of the solar electrons are represented
for three different hours of the day. With vertically falling sunbeams,
at 12 (noon), there is formed a symmetrical "umbrella" of conductive
lines; for the imaginary axis of the reflection path passes through
both the center of the earth and also through the theoretical center
of attraction. The range formed at about 10 o'clock is unsymmetrical;
the branch pointing to the south is shortened, and the effective
path to the north is lengthened. Still greater is the distortion
in the case of the reflection. umbrella formed in the evening twilight.
There the northerly-directed branch is so expanded that it does
not touch the earth again; therefore this line of propagation is
useless for practical communication. In both cases the influence
of the ideal center of terrestrial attraction is plainly recognizable.
Practical experience is accordingly confirmed and explained by the
Fig. 3 - Short wave lines of conduction in winter.
According to this assumption, there hangs over the earth on the
day side, a multiple "umbrella," which contains, besides the lines
shown, all the intermediate stages. At the same time there is a
possibility of communication between any two places on the surface
of the earth, which are touched by the same line of conductivity.
The lines themselves are given continuous excitation from solar
In the course of a day, in view of the rotation of the earth, each
point on the surface of the earth describes a fixed path in this
"umbrella" structure, and finds operating conditions periodically
changing. Besides the daily revolution, the earth annually completes
a circuit about the sun; whereby there is caused a constantly changing
angular inclination of the earth's axis to the sun. This second
motion of the earth in the cosmically-located network of conductive
lines (which are therefore fixed in space) is the cause of the changes
in range which occur during annual periods, as may be seen from
Figs. 2 and 3.
The ranges indicated in Fig. 1 may again be recognized over the
earth, which is shown in its summer and winter positions. Although
both illustrations show the same time position of 18 o'clock (i.e.,
6 P. M.) Greenwich time, the continents differ greatly in their
positions to the network of conductive lines. For instance, the
course of radio waves from Europe to South America is considerably
longer in winter than in summer, and the operating conditions are
worse. - Wissen und Fortschritt.
Posted February 11, 2015