Evening star. [volume] (Washington, D.C.) 1854-1972, 1925-02-08
RADIO GOSSIP AND NEWS

Deep, died-in- the-wooi scientists
are now taking a serious interest in
the many phases of, radio transmits
sion and reception, and may evolve
standards for methods, frequencies
and measurements which will aid
broadcasting and benefit the denizens
of radio land here and abroad.
The American section of the Inter-
national Union of Scientific Radio
Telegraphy, at recent meeting in
Washington, reported on many prob
lens on which research is under way.
"A resume of the session by DR.. ]. H.
Dellinger of the Bureau of Stand
ards states, in part, as follows:
There is great increase of in
terest in radio measurements, be-
cause so many people, who have gone
into all phases of radio design and
engineering, have found it essential
to secure real measurements. The
accurate measurement of radio fire.
quencies has attained international
importance and popular as well as
scientific interest, because the reduc-
ton of interference in radio recep-
ton depends upon it. The vast in
crease in the use of radio necessi-
tates the operation of transmitting
auency as possible. A practical limit
to such crowding is the accuracy of
maintenance of station frequencies.
The work of numerous investigators
Is providing means to give the neceS-
sary precision of measurement, con-
stancy of adjustment and absolute
accuracy of frequency basis. Inter
national comparisons of frequency
standards have shown a very salts
l..
esting means of making such COM
parsons is the piezoelectric osoil-
lator, a new device which is contrib
uting greatly to current progress,
especially in the use of very high fire.
quencies or short waves. The piezo-
electric oscillator is essentially
piece. of crystalline quartz. Methods
and apparatus have been worked out
to use such a device to control the
frequency of radio transmitting
station, thus giving constant fire.
quency stations.
There is increasing use of appara-
tus for measuring the field intensity
of radio waves; a number of methods,
some of them rapid and convenient,
are being used extensively by inves-
tigators.
DR.. l.. W. Austin stated that meas
urements show the average intensity
of signals from European and Cali
fornia stations has been some what
less during 1924 than in 1928. The
iations of the intensity of re-
ceived signals from the high power
station at Bordeaux, France. have
been found to be the same in France
as in the Uunited States, whereas no
such correspondence in the received
signals is found for measurements in
the two countries on the transmitted
waves from the high-power station
at Rocky Point, Long Island. Meas
urementS of the strength of signals
from European stations show drop in
signal strength just after sunset in
Europe. Observations of signals from
high-power stations over greater dis
tances than have been hitherto at
tempted as. for example, from Java
to California, show that the low-fre-
quency stations transmitted to great
er distances than hitherto indicated.
Measurements at frequencies above
5000 kilocycles indicate that the fad
ing of such signals is greater and
the reliability of transmission less
at distances under 500 miles than at
greater distances. In the Winter
frequencies above 5000 kilocycles are
observed to be transmitted much bet
ter in the daytime than at night, the
reverse of conditions with lower fire.
quencies.
DR.. A. H. Taylor reported that the
committee on variations of radio
wave direction" had found that a
shift of the apparent direction of the
waves from long-wave stations oc-
ours at sunset. The direction shifts
toward the east before sunset, re-
turns to normal at sunset and then
usually shifts to the west. The exact
- &c f,,1l
determined. Some variations of di-
rection in broadcasting station trans
missions have been found at night.
At very high frequencies the changes
of direction areyvery rapid and very
great, 30 that 0direction measurements
are quite impossible.
Measurements of atmospheric dis
turbances produced in low-frequency
receiving circuits during the last
three years indicate that their in
tensity.. was greatest in 1922 and
least in 1928 Observations of at
mospheric disturbances indicate that
their direction often corresponds ac-
curately to the position of storm and
cloud areas over the country. At
frequencies of more than 1900 kilo-
cycles atmospheric disturbances are
comparatively mild in the daytime,
but at night in the SUNNI time they
are worse.
f. F. w. Alexanderson, in pre-
senting the report of the committee
on measurement of interfering
radiation said that portable
direct reading instrument for field
strength measurements has been de-
veloped, which would make it posi-
BILE to determine the precise amount
of interference, not only on the main
wave of a station, but in the side
bands and harmonics. The use of a
standardized direct-reading instru-
ment of this kind will make it pos
sible to obtain actual statistical data
on interference produced by various