Evening star., 1924-08-31

kilovolt line. The aerial is $50 feet
long, and tho lead-in wire from the
aerial to the house 10 rubber covered
wire. laid on the ground for 500 feet.
No trouble has been reported since
this new aerial was installed.
A rather common source Of radio
interference ts the thermostat control
of electrical appliances. The periodic
breaking Of the circuit by the control
sets up an arc which. in a number Of
cases. has made the receiving set in
the home imperative.
There was considerable discussion ef
the type OF set to be used In tracing
sources Of interference, 1t being
generally agreed that a very sensitive
loop set should be used. One Of the
sets described utilized a non -directional
loop aerial mounted horizontally in the
top of car. While 1t would perhaps
be more advantageous to use q small
vertical loop SO as to take advantage
Of its directional effects. the non-di-
rectional loop also seems to be de-
sirable under certain conditions. The
types of sets which appear to have
given the best service for noise de-
lection and location arc the reflex and
super-heterodyne types. SO arranged
and convenient for use in an auto
mobile.
In q recent case Of radio interference
1t was found impossible to get COM
pass action from the loop Of the ex-
ploring set until the rest of set was
shielded by means Of sheet iron. The
radiation from the source Of trouble
apparently affected the tuning circuits
within the exploring set.
Secretary Of Commerce Hoover has
called the third national radio con-
ference for the better voluntary reg
ulation Of radio. to be held In Wash
ington, beginning September 80.
Two such conferences have already
been held. one in February, 1922. and
one in March, 1923. both Of which
were generally attended by the per-
sons and organizations interested.
The result has been a lessening fric-
tion and misunderstanding through
the voluntary cooperation Of the in
dustry, the public and the Depart
ment Of Commerce. especially in the
reduction of interference and the i'm
provement of service.
The growth of radio and par
ticularly the multiplication OF broad
casting stations and the consequent
congestion Of the air has made neces-
sary a consideration Of many sub
jects and perhaps a revision of some
present methods. Some of tho mat
ters which will be discussed and
considered at the conference are:
Revision OF tho present frequency
or wave length ALLEGATIONS. to reduce
interference.
Use Of high frequencies or short
waves
Classification Of broadcasting sta
tions: possible discontinuance Of class
G stations.
Interconnection Of broadcasting
stations
Limitation Of power: division Of
time; coming Of broadcasting stations
Means for distinguishing the iden-
tity OF amateur calls from foreign
countries.
Interference by electrical devices
other than radio transmitting sta
tions.
Relations between government and
commercial services.
Such other topics as may be proposed
by the conference.
To facilitate tho work Of the con-
ference tho various groups in the
radio field will be asked to name rep
formal advisory committee of the
conference. AS at present planned,
the groups to be represented will be
as follows: Listeners, marine service,
broadcasting Zone from each inspec-
tion distric) engineering. trans
oceanic communication, wire inter-
connections, manufacturers. ANA
teurs, point-to-point communication,
Government departments.
Tho committee so constituted will
hold public hearings. All persons or
organizations having any suggestions
to make or views to express upon
any features of radio activity are
urged to attend and will have full
opportunity to be heard
Some of the matters suggested for
consideration are not within the reg
ulatory control Of the Secretary. As
to such matters, any conclusions
reached by the conference can be-
como effective only by voluntary
adoption by the interests affected. AS
to the features falling within the
powers of the secretary the recon-
mendations Of the conference will be
advisory to the Department.