Evening star. [volume] (Washington, D.C.) 1854-1972, 1929-05-14

STATIONS URGED
Engineer kd"icas High Power
10 Overcome Wan-Made
Interference.
BY MARTIN COnEL.

Engineering opinion seems to DC al
most OF enc accord in favoring the I'M
position Of no limitations upon broad
cast power. Thus. wn;n Edgar Felix.
the radio ConSu'tGnt Of thu Nc tional
Electrical Manufacturers Assoc ton,
suggested that power of 100000 watts
NAV be deTclopcd to oIercome man
made interference with radio reception.
he occa stoned no great amount o. sur
prise among the radio tschn;cianS gath
cred in WashingtoE for thu annual
convention OF the institute OF Re- do En-
gineeTs.
His suggestion that the broadcesting
structure may ultimately comprise on,y
80 stations, each of 100000 watts
power and each utilizing one OF the SO
available wave lengths exclusively, met
with little favor. however. Not only
would such a plan Of broadcast or5anl-
zaticn be highly impolitic, but 1t would
hardly be possible for the Federal radlo
authority To pick out cnly 80 survivors
among the 900 odd stations now operat-
ing throughout the United States.
Moreover, in view of the purely local
Service rendered by the many stations
of very low power. such plan would be
like demanding that all rural end small
town folk read only the great metropol-
itan newspapers. RELOCATING the local
stations to limbo would be analogous 10
eliminating country weeklies and dailies.
Superpower broadcasting was not the
only means recommended by Mr.. Felix
for eliminating interference. In addi-
ton to having transmitterS put out as
much power as possible TO override in
reference, he would have the engineers
engaged in the design and manufacture
of household electrical equipment give
due attention to the radiating proper
ties Of such equipment as they affect
radio reception. Often such devices as
vacuum cleaners. electric refrigerators,
oil burners, fans, cash registers and
X-ray machines interfere annoyingly
with reception over several square miles.
Recognize Problem.
Radio engineers. said Mr.. Felix, have
recognized this problem and have at
tempted to render the radio receiver less
sensitive to the influences OF, power-line
fluctuations by using cflokes to suppress
them and incorporating adequate shield
ing. The power companies have found
II desirable to inSulate and test electro
cal appliances. motors, dynamos and
electrical machinery to avoid complaints
from listeners.
With respect to superpower, Mr.. Felix
declared that the present tendency to-
ward increased power in broadcasting
has only brought us to the threshold
Of development in this direction,
1T is quite within the scope OF the
engineers Imagination" he said. Ito
visualize ultimately a broadcaSting sys-
tenn comprising transmitters of mil
lion-watt power. Compared with other
systems in daily use this is by no means
large unit; a power bill Tor such
broadcaSting station might run from
$50 to 500 an hour We use several
times that power in transporting week
end tourists to a single metropolitan
bathing beach. While a million watts
represents a substantial increase in the
power of broadcasting. such power need
not be feared as dangerous monster.
"A system of broadcaSting with trans
mitters of this order Of power would re-
QuiFe somewhat altered receiver design.
Obviously We would employ less sensitive
receivers. and instead Of an exposed
aerial system We would use an adjust
able pickup means shielded from in
coming impuiSes 10 a degree determined
by the field strength of the nearest
station. Stations of such
power could serve the centers OF popu-
lation with antennas located at some
distance from congested centers.
Give Wide High-Grad Service.
ALLEGATIONS of wave lengths under
these conditions would be simpliled be-
cause the high-grade service range OF
such stations might well be as much as
500 miles Ninety such stations spread
geographically over the country would
give 10 or IL program choices at any
point, and may be compared with pres
ent conditions. where perhaps less than
40 per cent of the area of the country
is within the wide high-grade service
range of any broadcaSting station.
Furthermore, the initial and main
tenance cost OF receivers would be
lessened and the quality Of reproduction
improved. with the consequent result
that the radio listening public would be
enormously increased. This, in turn,
would have a healthy effect on the eco
nonical position of the brOadcaster."
Mr.. Felix concluded that such broad
casting system would probably cost from
$50, 900 900 to 5000, 900 900 annually TO
maintain. compared with about $35 ,00O,-
900 spent for the annual maintenance
Of the present system.
The highest power authorized for use
in this country today is $4,000 watts
and only handful Of stations use that
much. One or two have a capacity OF
100. 900 watts, and one has tried this
out experimentally with excellent re-
suits. In Prague a station rated at l20,-
600 watts is now building. Russia Is re-
ported to be building four stations OF
rs 600 watts each. On the long waves
used for transoceanic code comn1unica-
ton power up to 10000 watts is en-
ployed.
(copyriEht, 1929. by North American News