The Pensacola journal. (Pensacola, Fla.) 1898-1985, 1917-12-09
DEVICE FOR SEEING
RADIO MESSAGES IS
NOW PERFECTED

An apparatus for seeing radio
messages for use in airplanes has
been perfected, and is described as
follows in the Electrical Emperl-
menter:
This apparatus consists of SEN
sitive Einthoven galvanometer with
small electric lamp. The light
from this lamp is focused thru lenses
on to a small mirror, which in turn
reflects the light thru magnifying
glass, the same as in an opera. glass.
The upper part through which the
observer looks is constructed on the
prismatic binocular principle, making
the sighting apparatus equivalent to
six times its length.
In other words, the observer does
not actually see the wireless signal
or wave literally speaking; he only
sees the effect of the etheric wave,
after it has impinged on the anten
ma attached to the areoplane. and
after it has past through the tiny
qucrtz fiber suspended between the
poles of a strong magnet and per-
pendicularly to the magnetic fluN
lines. If weak current, such as q
received radio signal current, passes
through this quartz fiber, the latter
will be displaced from its normal
position in direction perpendicular
to its axis and to the magnetic flux
lines.
The fine galvanometer string
moves in front of a narrow slot, IL
Illuminated by the small lamp fed
from a battery. An optical repro
duction of the slit and wire is thrown
on the sensitive retina and pupil Of
the eyes, one of the most sensitive
H.
comes in, in the form of telegraph,
dots and dashes-short and long sig
nals-the quartz string is deflecteC
back and forth correspondingly; thus
the radio operator "sees" the incom-
ing signals. A short DETECTION in
dicates "dot," while longer de
Election represents dash"
The apparatus just described
serves the same function as the de
tector used in all radio receiving set3
If is usual therefore to connect j;
with some form of tuning coil or
transformer, so that the outfit car
be readily tuned to the proper wave
length.
The instrument may be held in
one hand If the operator desires to
write down the message received
This he can readily do with little
strument and the other on the NC
sage pad as he writes. A good oper
ator can write down message with
out looking at his pen or pencil. Be
sides, it is not impractical to install
a light weight typewriter on the
acceptance; and "touch typists'
never have to look at the keyboard
Radio and wire telegraphists arc
| daily using the typewriter in jus
this way by the thousands.
| The principle of the optical anc
Photographic reception of radio sir
nails is not new. The efficacy of thu
Einthoven, string galvanometer II
| this role was quite thoroughly test
ed out by the Poulsen radio expert
both in this country and abroad. Tt
| American Poulsen interests
Federal Telegraph Company, Of Sal
| Francisco-spent many thousands o
dollars in their researches on thi
! method of receiving radio signals
I the only difference being that tn
movements of the quartz string wer
! highly magnified and recorded pho
Geographically on a moving film.
is hopeful that this work may I
taken up again and followed up to
successful conclusion. The Unit
States needs the best it can get
every branch of its military se<v
and it would seem that the appara
tus here described and being sae
cessfully manufactured in German
can certainly be duplicated. and Y
doubt considerably improved. in TIL
, nation of vast industrial and scien
tific resources.