Evening star., 1923-05-06

On VI 10 the radiophone broad
cast voice of the most widely known
transmitting station in the world will
undergo an important change. On
that date NAA's far-reaching voice
will leave the 110-meter ether lane
and begin speaking through the me-
dunn of a broadcast wave OF 43o
meters.
This will be welcome news to many
thousands of radio fans. especially
the music-loving fans.
1t means that MAS invisible music
waves and also its speech waves will
thereafter be "in resonance" with the
receiving outfits of all radio fans
instead of only favored few, or
rather that all radio fans without eX-
ception will be enabled to adjust
he circuits of their receiving outfits
- resonance with NAA.
Hear Popular Bands.
AS a result. the popular Wedn esday
evening concerts OF the United states
Marine Band, the Friday evening con-
rarts of the Washington Navy Yard
land and the daily broadcast lectures
Of tho various departments OF the
government in Washington will again
he simultaneously reproduced i'll
our eastern. southern and middle
western states and even at points in
Canada.
When exceptionally favorable at
mospheric conditions prevail. these
programs may be received at points
along our Pacific seaboard, In our
West Indian possessions and in the
Panama Canal zone.
These governmental radiophone
broadcast programs were inaugurated
wi, ,o1 fny~ tha r,f x I'M q
:; scientific investigation and study of
the radio technical and accoustical
features involved in radiophone
hroadca sting. They constituted an
innovation in radio research and ex-
detrimental work-the first project of
its kind ever undertaken-Where
thousands of laymen in radio, or radio
fans. situated in twenty or more
states, co-operated with the govern
ment radio engineers in one of its
laboratories with a view to ascertain
ing and correcting technical faults
and thereby improving the quality of
radiophore broadcasting throughout
the United States.
Stop NoF Programs.
These experimental programs were
broadcast weekly from the NOF labo-
ratory station at Anacostia, u. c.. on
n wave length of 4l2 meters The
experiments and Investigations eX-
tended over an interval of several
months time. the participants being
the government radio experts at Ana
costa. the famous Marine Band and
several thousand radio fans.
The Investigations were completed
last December and the NOF expert
mental programs were terminated at
that time. NOF having remained
silent al a regular broadcaster of
rAdiophone programs since.
The popular demand fer the con-
'inuance OF the band concerts, espe-
rially those situated in the more iso-
lated localities, became so great that
last the hand concerts regularly
through the nearby NAA station
which is situated within visual dis
tance Of the Anacostia laboratory.
Experiment With Waves.
An attempt was made to utilize the
AZ meter wave formerly employed at
NOE. but owing to difficulties of a
technical nature it became necessary
to employ some other wave. There
are several individual transmitting
*ets installed at NAA. all Of which
are associated with their individual
operation. The peculiar tnductive ef-
fects from these antenna systems
were found to be such that virtually
no radiation of energy could be OBJ
tanned from the radiophone broadcast
antenna when adjusted to Alp meters,
although good results could be OBJ
tanned on the other short waves.
A wave length of 710 meters was
finally selected as being the most
suitable for use at that time. there
fore the apparatus was adjusted to
this wave and the band concerts and
other features have been broadcast
on this wave
However, since the employment Of
the 710-meter wave, while satisfac-
tory from the technical viewpoint, it
has had tho result Of preventing a
large number of fans from picking
up the broadcast programs because
the frequency or length of the wave
is beyond the range of most broad
erately priced commercial receivers.
DimcuIt Adjustment.
The maximum wave length range
OF adjustment of most of the early
broadcast receivers is around 500
meters. Such receivers cannot be
brought into resonance. or electrical
harmony SO to speak, with a distant
station transmitting on a wave length
"t 40 meters unless extensive modi-
iications are made to the receiver,
and unless the receiving outfit is in
resonance with the distant transmit.
ling station there will be no repro
duction of signals regardless of the
amount of energy in the passing
wave.
The required notifications consist
or properly associating additional
suitable coils Of wire. or condensers,
or both, In the receiving circuits for
the purpose Of increasing the product
or the inductance-Capacity value Of
The circuits and thereby enabling
their being adjusted to resonance
with longer wave signal impulses.
Many Miss Concerts.
Ii may logically be assumed that
tho required changes were made in
only comparatively few instances be-
cause of the difficulties to be en-
'ountered by persons not familiar
with the technical aspects of radio
and also due to the trouble and ex-
pense involved. Thus with hundreds
nf stations broadcasting on wave
lengths around $50 meters or we'll
within the wave length range of ali
broadcast receivers, it Is likely that
MAS 7l0-meter broadcast wave has
been serving a numerically restricted
audience.
With the change to 4s5 meters,
however, NAA's signal impulses NAV
betuned in by the owner Of virtually
every broadcast receiving outfit and
AS a result its invisible audience,
especially on Wednesday and Friday
evenings. should be as great numeri-
cally and as widely scattered as NOF's
former audience was indicated to be
by the thousands of letters and post
cards submitted by radio fans.
Result Of Conference.
The forthcoming change of MAS
broadcast wave to 4S5 meters is to
be made as a result Of recommends
ttons submitted by the second annual
radio conference recently held In
Washington to devise ways and means
of bringtng order in the radio world"
Ono OF tho decisions made as q re.
suit OF this conference was IN oman