January 1935 Short Wave Craft
[Table of Contents]
Wax nostalgic about and learn from the history of early electronics. See articles
from Short Wave Craft,
published 1930 - 1936. All copyrights hereby acknowledged.
The 5-meter band (56-64 MHz) allocated
to U.S. amateur radio operations in the 1930s was reallocated in 1946 to television broadcasting. However,
Hams still are permitted to operate on 6-meter (50-54 MHz) and 2-meter (144-146 MHz) bands
on either side of 5 meters. Therefore, this article on non-line-of-sight communications within mountainous
regions will still be of interest, even if only from a historical perspective. There is an interesting
comment made about feeding a vertical 1/4-wave antenna from the top rather than from the bottom (with
the entire structure located 50' above the ground). No explanation is offered as to the reason.
Over Mountains on 5 Meters!
Remarkable distances, considering the intervening mountainous country, have been
covered on the 5-meter band as shown in the accompanying picture.
The old question of whether or not communication on ultra high frequencies can be held between stations
located in mountainous areas seems to have taken a backward step within the last few months. Scientists
have claimed that ultra high frequencies are more or less quasi-optical - that is, the transmitting
and receiving stations must be in optical sight of each other.
Recently Dr. Marconi in an interview with the editors, stated that he had been successful in getting
through mountainous areas on the ultra high frequencies but that he was unable to state whether or not
the signals went over or through the mountains until further tests had been made. In the drawings, we
have endeavored to show the readers the condition which exists between three stations namely portable
W3AC at High Point Park, N.J., W2HBW at Walden, New York, and W2AMN (George W. Shuart) located in Ramsey,
N. J. Perfect communication can be held at any time between W2AMN and either of the other two stations.
Several ranges of mountains existing between High Point Park and Ramsey have absolutely no effect
on the signals W2AMN receiving an R8 report from High Point! Between W2HBW and W2AMN, there is located
mountain ranges as high as 1500 feet and perfect communication can be held at any time, with an R6 report
at either end. The transmitter at Walden is an M.O.P.A. using a matched-impedance antenna system for
transmission and reception. The transmitter at Ramsey is the same one that was described on the October
issue of Short Wave Craft, using the "long lines." For reception a vertical 8-foot antenna is used,
located some 50 feet above the ground, with the lead-in being taken from the top! The observations and
test between the above three stations have proved absolutely that it is possible to "get through" mountainous
areas, with ultra high frequency transmitters and with reliable communication. All work so far has been
done on 5 meters, but in the near future higher frequencies will be tried to determine whether or not
the same holds true.
Posted January 26, 2017