Evening star. [volume] (Washington, D.C.) 1854-1972, 1929-05-17
MULT|PLEX WAVE
) USE IS FORECAST
Or. MeiSsner Predicts Voice
and Code to Be Carried
on a Channel.
BY MARTIN CoDEL.

Multiplexing telephony and biography
for simultaneous transmission and re-
ception on the same wave length may
be confidently expected as an early
radio development.
Firm belief in the practicability Of
imposing voice along with code signals
on the same channel was expressed by
DR.. Alexander Meissner, the noted Ger
man inventor, in an interview granted
while he was in Washington this week
for the annual convention of the In
stitute of Radio Engineers. Not only
telephone and telegraph, but photoradio
or picture signals as well, can be car
ried on identical channels without in
terfering with each other, according to
the eminent German scientist, who is
the chief research engineer for the Tele-
funken Co.
That concern occupies a place in
Germany'S radio structure correspond
ing to the Radio Corporation of America
in this country Its transradio ocm-
pany is an operating subsidiary for
radio communication with the rest of
the world.
DR.. Meissner's remarks were particu-
revolution in long-diStance wireless
communication is foreshadowed by an
announcement from London that a
multiplying method known as the
Marconi-Mathiew multipleX system has
been tried out with success on the Brit
tsh directional beam to Canada by
means of this invention. Recently an
official of the British Marconi Co. was
able to talk with Canadian Marconi
official at Montreal over the beam code
channel that links England and Can
ada.
ObviateS Special Stations.
The chief advantage claimed for multi
picking is that 1t opviateS the expense
of special wireless stations for inter-
national telephony. Moreover, it is said
that the system may be operated with
greater speed, economy and efficiency
and with lower power than the present
transatlantic telephone employs.
DR.. Meissner agreed that the future
of long-distance radio rests upon the
beam, which confines signals along d.
rected paths of transmission so that
their energy may not be wasted by diff
fusion in all directions. The famous
British beam which Is used on circuits
linking the whole British Empire, is par
alleled in this country by the protector
beams employed at its Riverhead, Long
Island, station by the r. c. A. for trans
oceanic message service. Operators Of
each claim advantages over the other,
but DR.. Meissner believes that he has
found new device that will improve all
beam transmission.
Employing horizontal antenna, in
stead of the usual vertical antenna, DR..
Meissner is using paraboic ref1ectors
so that the angles of radiation may be
readily changed as a change in direc-
ton is desired. With his system the
German tranSradio has worked River
head and switched the same beam to
its South American circuits with high
efficiency. He said he expected that
experiments with his horizontal an
tenna would shortly be conducted in
this country.
Uses Extreme Short Waves.
DR.. Meissner also has been working
with the extreme short waves for air.
craft radio. He told the writer that he
has been able to keep in continued con-
tact by voice with plane travelling up
to 200 kilometers (about 100 miles, by
transmitting with about 500 watts power
on a wave length of between 3 apd 4
meters. The problems of energy con-
troll on such very high frequencieS, how
ever, leave much to be desired in utiliz-
ing the channels in the present grave
yard Of radio" in which American ANA
teurS are now confning much Of their
experimenting.
This is DR.. Meissner'S first visit to this
country, although his name is men
toned along with those Of the Ameri-
cans De Forest and Armstrong in all
discussions of the famous feed-back cir
cult that makes present radio possible.
In fact, the MeiSsner feed-back circuit
was perhaps the most important of all
the German patents seized by the alien
property custodian during the war. Al
though the MeiSsner claims to the in
vention of the feed-back were appar-
emily nullified by the recent decision Of
the United States Supreme Court in the
Armstrong-De Forest litigation, the
Navy IS still using his circuit and GER
tain claims centering on it remain to be
adjudicated by the war claims arbiter.
DR.. MeisSner holds numerous hon.
orary degrees for his work. He Is a
lecturer In the Berlin Hochschule. In
1925 he was awarded the Heinrich
Hertz gold medal In recognition of his
inventions In the radio field. He Is said
to have been the first to place a vacuum
tube oscillator in operation in America
when In connection with reception of
the giant German station at Nauen, by
the then German-owned station at Say
vile, Long Island, he constructed and
sent over a tube oscillator for hetero-
dyne reception.
Copyright, 1920