Evening star., 1930-05-24
HOME TELEWS|ON
IS |SENG|NEER'S HOPE
Experiments Made With New
Variety of Tube to De-
veIop Apparatus.

NEW YORK (R.-Television as easy
to receive in the home as sound radio
that is the hope of DR.. Vladimir ivory
kin. research engineer.
Casting aside such apparatus as neon
lamps motors and scanning disks com
mon to most receiving systems. this in
vestigator has taken cone-shaped tube
and attempted to make it do electrically
what has been accomplished mechari-
! cally.
1t is a cathode-ray tube, similar to
! that used to visualize electric current
| and for other oscilligraph work, but
with its internal construction changed
| so that, when connected to a receiver
it reproduces television images four by
! five inches in size upon f1uorescent
! screen in the fiat end of the glass en-
! closure.
| First announcement of the device,
! termed kinescope, carried with 1t the
| belief that preliminary experiments in
! dicated 1t might bring the same solu-
| tion to television that the vacuum tube
! gave to sound radio when it replaced
the crystal detector and made possible
| the broadcast receiver of today.
Not Yet Practical
The tube has not yet been reduced
to a practical basis. Beyond the fact
that its possibilities are being investi-
gated, 1t hasn't reached the stage where
| It can be considered for ordinary use.
DR.. Zworykin, who did his preliminary
work in the Westinghouse laboratory at
Pittsburgh, now Is continuing his re-
search efforts at the r. C.. A. plant at
Camden, N. j.
The picture reproduced by the kline
scope is green and not pink like that
with the neon tubes. The image is
| built up by pencil of electrons which
lombard the screen in the end of the
tube. The beam moves back and forth
in step with the scanning light ray in
the transmitter by electrical means.
It's speed is SO rapid that the eye gets
the impression of a continuous moving
picture.
BY the use of the f1uorescent screen
the eyes vision is aided, making posi-
BILE a reduction in the number of pic
lures transmitted per second without
noticeable flicker. A greater number of
greater detail to the picture without in
creasing the width of the radio channel
used.
Divided Into Two Parts.
In reception, the output of a receiver
is amplified and divided by a filter
into two parts, the synchronizing fire.
Quency OF impulses ana Lfle picture anu
framing signals. Each set of impulses is
applied to separate parts of the tube, re-
sulting in automatic operation, without
noise.
The tube has filament, which gen.
crates the electronic beam. The beam
passes through small hole and then
again through hole in the first anode
or plate This anode accelerates the
electrons to a velocity of 800 to 400
volts. A second anode, which is me-
tallic coating on the inside of the bulb,
speeds up the acceleration to 5000 or
1000 volts, or at a velocity of about
one-tenth of light. The second anode
also focuses the beam to a sharp point
on the screen The screen is conduc-
tive to remove electrical charges coming
from the beam.
BY means of DETECTING plates and coils
mounted outside the tube Whe beam.
which leaves a light, hourescent line, is
made to move back and forth. The
brightness of the line, upon which are
impressed the lights and shadows of the
transmitted picture, can be controlled
to any desired extent.