Evening star., 1926-01-17
RADIO DEPENDENT
ON MATHEMATICS
Science to Play Big Part in
International Test Week
Shortly.

might nave been expected To be used
&tS aI Immediate aid 10 the great
radio development of the last four
years, VIII play a prominent part
IN IN" radio hrOaucasring reception
on both sides of the Atlauti" during
International Test week he latter
part of tnis month
Sponsored by ii radio publication
and finding ready response and
nearly cooperation from broadcast
erS spanning the continent. radio lis
lentfs vii! Join liz attempting 10 PICK
uP foreign sta ions during i week
when the United States stations will
Dc "ou the 4ir only at stated in
teryalS.
Ma th, the horror OF high school
days and the dread of even the high
and mighty college senior, will play
leading role in the interna ,ional
drama that Will be enacted j few
days hence when thousands of lS
tenerS on both sides OF the ocean
VIII strain ears and turn receivers
up 10 the highest notch OF volume to
catch signals from another continent
5000 nI4ies away.
For OF the millions of receivers in
American homes ana the millions i'll
homes across the Atlantic many of
them Were worked out on paper by
mathematIcianS long before d base
board was scratched or panel
drilled.
New Com 1inations.
Outstanding among them are the
combinations of tuned radio fire.
quency and regenera ion which are
probably the most popular radio cir
cults of today; and the neutrodyne,
the senSatIun OF last W inter anu still
popular fayorite Notwithstanding
the great popularity of the double
stage radio frequency, de,ector and
audio receiver this Winter. The same
magazine that is sponsoring the in
ternational tests sponsors this year
o-called universal receiver"
combination OF tuned radio frequency
and balanced regeneration. succeed
ing previous set also worked out
by mathematics before beng put on
the testing table.
In all radio sets there is some form
of regenera ton present, in which the
output OF the detector tube is fed
back and used over again in build
ing up the signal strength usually
fed to 1t through one. two or three
radio frequency tubes. In most of
them ii is balanced. sometimes on the
delector tube itself and more fire.
Quently on one of the radio fire.
Quency tubes to prevent any radia-
ton from going out on the aerial
and interfering with reception of
neighbors If the detector tube or
radio frequency tube spills over.
OF the types using combined regen-
Grafton and balanced radio frequency.
that evolved out of the dealm of math-
ematics by two eXperimenters In the
Harvard radio laboratory, has struck
a popular chord.
Experiment in Mathematics.
The builders, before they ever
stuck their parts together. expert
mented with mathematics to find
out what the proper volume Of re-
generation should be with sub.
merged primary laid in a slot Of In
material and covered by a
few windings of a multiple turn sec
ondary.
They found q high ampliflcation
and learned when the set was
put together that the volume of sig
nals could be increased several times
by adding a plate coil which could be
brought into electrical opposition with
the secondary. Their circuit has
proved popular and they leased over
their rights to manufacture Of that
they called a "regenaformer." This
with notifications on the re-
Sluc, uSltl5 Tie lie" "a
tubes and bases, is listed today as the
universal receiver" 1t may be used
in combination with any type of au-
dio frequency amplifier, transformer
coupled or resistance cou-
pied. and is claimed to give great dis
tance. volume and selectivity. The
of the 'regenaformer" is
said to be 80 per cent of that predicted
by lab" mathematics.
The well known neutrodyne came
out of the laboratory, and application
Of rnathematics to radio of Prof. L. A.
Hazeltine of New York This circuit
also is a development arrived at before
tubes had been placed in sockets or
panels drilled. The amplification con-
stants were predicted long before the
circuit had been placed in operation
and equaled the most enthusiastic
dreams of Prof. Hazeltine
The neutrodyne is manufactured by
several makers of receiving sets One
Of the largest manufacturers will give
cups to broadcast listeners receiving
foreign stations on sets built by the
Multiple Tube Set Needed.
The thrill of getting 2LO at London,
Aberdeen, Madrid, Berlin or Paris will
come, however, only to those using
tube sets, Notwithstanding
he fertility of the American invent or
the field of mathematics TO
produce radio amplification which
would probably not have otherwise
been obtained.
The owners of sets using the popular
super r-heterodyne circuit should have
IN excellent chance 10 receive one or
more of the foreign stations SO
nf
or one OF the many popular
uned radio frequency hook ups so
much in use this Winter. Anything |
hort of four tubes, however. will prob |
ably not be among the lucky receivers !
o pull in the foreign broadcasters |
or power, and power alone, will do the |
rick. And power means radio fire. |
Iuency to ampiify signals befoer the |
ietector tube and audio frequency to |
,hanEe them to tones audible to the !
human ear.
If set owners in Washington are un- !
ortunate enough to strike several ,
nights during the week such as last (
\ ednesday or the preceding Thursday !
light they will be lucky to get any |
hing at all. For on both these nights |
| was as if a blanket were laid over |
he city, preventing proper reception
II distant stations.
W.,D. Terrell. chief radio inspector
f the Department of Commerce, lays
his pail over broadcasting on the au-
ora. borealls. or nor .hern lights, which |
,roduce electrical discharges that
lUarf the efforts of man, notWith-
t. nding his vaunted so kilowatts of
'oWer. Although the northern lights
re not always visible, their effect |
uay be widely felt, and on nights the