Radio Broadcast - 1925, February - 113 Pages ... - VacuumTubeEra

The March of Radio 695
communication is striding forward rapidly.
The successful listeners during the test were
not skilled amateurs. They had sets using a
half or a third as many tubes as did Godley's,
they .had ordinary short antennas, and in some
cases loops only, and they received radiophone
signals, whereas Godley received dot and dash
telegraph signals. This latter fact is of much
more importance than one might think; the
same amount of power used for telegraphing as
used for telephoning is good for possibly twice
the distance of communication.
It is not easy to conceive of just what these
long-distance tests mean from the standpoint
of power. A station rated as 500 watts probably
radiates about 100 watts of power, and
the energy thus thrown off spreads out in all
directions. Much of it is radiated up 50 or 100
miles and there is
partly dissipated in the semiconducting
atmosphere and partly reflected
down again to the earth. Part of the energy
is absorbed by buildings, and even by vegetation
on the earth's surface, which is evidenced
by the fact
that the signals which
travel over land between
two stations are by actual measurement
only about one third as strong in summer as
in winter.
In spite of this dispersion, absorption, and
reflection, there is still left sufficient power
after a voyage of 4,000 miles to give an intelligible
signal to the radio listener. Imagine a
500 watt incandescent lamp burning in France,
Italy, or England, being visible to thousands
of observers in our country! Imagine communication
being carried on between those
countries and ours by a blinker code worked
on the lamp. In trying to imagine such a feat
remember that our best lighthouses, having
lamps of 100,000 candle power or greater, are
visible at most over perhaps 50 miles. One
feat which has been accomplished in radio is
still ailing to be solved in the realm of optics,
that is, the magnification of the received signal.
If we had some apparatus through which
to look, which would do the same thing to
the light waves as our amplifiers do to the
radio signal, then possibly the 500 watt lamp
in Europe would be
visible in America.
Unfortunately,
it is
HENRY FORD S RADIO PLANT
At Dearborn, Michigan. The three towers of the 1000 watt station WAV which operates on 1713 meters
with Ford stations at Springfield and Jackson, Ohio. The four lake carriers of the new Ford Fleet are in
constant communication by radio with the home office, wherever they may be on the Great Lakes, which
can be a maximum of five hundred miles distant. More than 400 messages a day are handled by the
operators, shown in the insert