August 1958 Radio-Electronics
[Table of Contents]
Wax nostalgic about and learn from the history of early electronics.
See articles from Radio-Electronics,
published 1930-1988. All copyrights hereby acknowledged.
Joseph Ryerson (see 1976 award), of the Griffiss AFB Air Development
Laboratory was thinking in 1958 when this Radio-Electronics article appeared about a method for exploiting
gravitational waves for communication purposes long before they were finally
detected for the first time in 2015. Even today, however, we are nowhere near
being able to control gravity waves. In fact, an Earth-based system is unlikely
to ever be developed due to the extraordinarily
wavelength of various kinds of gravity waves with periods measured in
minutes, hours, days, hours, weeks, and longer. Space-based sun-orbiting
interferometer satellite pairs (Laser
Interferometer Space Antenna - LISA) are in the planning stage to more
accurately measure gravity wave. I wonder if Mr. Ryerson was/is around to
witness the gravitational wave detection? Another major topic was the
Moon Radar project where the Army Signal Corps offered to send QSL cards to
amateur radio operators who reported picking up the signals bounced off the
lunar surface. Doing so not only encouraged the sport, but information provided
regarding location, time of day, frequency (Doppler shift), and signal strength
assisted the Army Sign Corps in assessing their network of Mini-track stations.
Use of Gravitational Waves for a wireless communication substitute
for radio is being explored by Joseph L. Ryerson, chief of the Advanced Development
Laboratory, Rome, Air Development Center, Griffiss Air Force Base, Rome, N.Y.
The proposal is still in the theory stage, no equipment having been built. Key
to the system would be gravitational coupling between oscillating masses. Ryerson
gave the example of a lead ball vibrating at a given rate in a frictionless bearing.
Its gravitational field should cause a "receiver" ball of the same mass to vibrate
at the same rate.
"Moon Dxing" is being encouraged by the Army Signal Corps, which
sends the QSL card shown here to listeners who report picking up radar signals bounced
from the moon. The signals, beamed from Fort Monmouth, N. J., by the Signal Corps
and the US Naval Research Laboratories, are on the US satellite frequency of 108
mc and are transmitted for the purpose of calibrating far-flung Mini-track receiving
stations. The Fort Monmouth transmitter aims 1.2 megawatts of radiated power at
the moon from a 50-foot parabolic antenna.
The 108-mc transmissions start 2 hours before the moon reaches its highest point,
and last for 6 hours - but not on a daily schedule, because of the possibility of
interference with transmissions from satellites on the same frequency. Diana signals
are usually CW, but are occasionally frequency-modulated with an identification
message in International Code. Pulse-modulated and CW signals are also transmitted
at 151.11 mc in connection with other moon-bounce research.
The 108-mc Jersey bounce has been received in Germany and South America. An extremely
sensitive receiver and directional antenna are required. Amateurs who pick us this
1/2-million mile dx should send a listener's card to Diana, c/o Radio-electronics,
154 W. 14th St., New York 11, N. Y. The information will be forwarded to the Signal
Corps moon radar project and will be acknowledged with a QSL card.
Voice-modulated signals have been bounced from the moon and received halfway
around the earth without appreciable loss of quality by University of Michigan researchers
working under an Air Force contract. This marked improvement over previous transmissions,
according to preliminary reports, was due to use of very short wavelengths (about
1 inch). Success of these experiments has led to predictions that commercial use
of the moon for intercontinental communications is only a few years away.
Posted July 23, 2021