Evening star. [volume] (Washington, D.C.) 1854-1972, 1930-09-21
RADIO CONGESTION
RELIEF GIVEN HOPE
Invention of British Scientist
Most Revolutionary Since
Vacuum Tube.

An eminent British scientist may be
the Moses who will lead North America
and the rest Of the world out Of the
wilderness of radio congestion. What
Is described by competent technical au-
thorities as the most revolutionary in
veation in radio since the vacuum tube
"A receiving system whereby the num-
Der of channels can be multiplied mani
folds about TO be brought to this
country for demonstration before
American radio engineers.
The invention is the "Stenode Radio
stat" by which it is claimed that
existing broadcasting channels can i'm
mediately be increased threefold, and
that all radio channels can ultimately
be increased up to 100-fold without
causing any heterodyne interference IN
reception.
The inventor is DR.. James Robinson,
former radio research chief Of the
British ROYAL Air Force. member of
Great Britains Radio Research Board
and well known in this country as a
radio scientist Of repute. Several Of
DR.. Robinson's assistants are now on
their way to this country with Stenode
apparatus for demonstration during the
Radio World Fair in New York this
week.
Means Marrow Path"
DR.. Robinson himself has accepted
an invitation to make the technical
laboratories OF Radio News OF New York
his headquarters when he comes to
America. about a month from now. He
will be accompanied by Percy w. Har-
ris. chief engineer and general man
arer of the British RadioStat Corpora
ton, Ltd and formerly editor OF sew
ersl English radio periodicals.
only the high standing of DR.. Robin
aon and the enthusiasm of those who
have viewed his apparatus has TENDED
To sllay the skepticism that has existed
in the United States since the flrst an
no1ncement of his invention last VIM
ter. Where broadcaSting wave IengGns
are at present 10000 cycles apart IN
this country and 5000 cycles apart IN
Europe. it is claimed that the Stenode
will receive stations without hetero-
dvne interference on a band less than
100 cycles wide. In fact, the word Ste
node is derived from the Greek, mean
ing narrow path"
T-he secret lies in "a quartz crystal
that is used instead of q number OF
sharply tuned cascade resonant CIR
cults in order to obtain high selec-
tivity. The band passed by this crystal
il only about so cycles, Consequently
anv interference on a frequency olt-
ferent from the frequency Of the oe-
sired station by more than so cycles
should be completely eliminated.
with the Stenode RadioStat the quartz
crystal circuit has so sharp a resonance
curve that practically none Of the SIDE
hand freuuencies are passed TO the sue
ceeding circuit"
DR.. TayIors CIassmate.
Dr Robinson was postgraduate
rIaSsnate in Germany Of DR.. A. Hoyt
rTavlor radio chief of the Naval Re-
search laboratories, who is one OF the
noted American radio scientists VINO
will follow the demonstration with Keen
According to reliable reports, the Ste
node principle is now being USED on
the telegraph circuit Of the Lonoon
Daily Mail between London ana Man
chester and has considerably multi
piled the amount of trattlc TINS me me
would normally carry by increasing tae
number of channels that can be USED
simultaneously and without interior
ence. .,..,s ,,.;4,,
wires il can also be done with radio
Fsuecially in the case OF teleVlslon VIII
this system become important, because
felevision now requires an extremely
wide band Of wave lengths. which con-
siderably limits the number OF tele-
vision stations that can go on the air.
r. Il alec claimed for the Stenode re-
ceiver that no matter how badly
feterodvned a distant station may be IN
an ordinary receiver or swamped by a
local. the Stenode Radiostat can tune
n in completely free Of all interior
ence'