June 1946 Radio News
Wax nostalgic about and learn from the history of early
electronics. See articles from
Radio & Television News, published 1919-1959. All copyrights hereby
"What's the big deal about a night vision scope for your rifle?,"
you might ask, since "I can buy an
infrared scope for my rifle on Amazon for under $100." The answer
is that no, it is not a big deal now, but in the 1940s while it
and deployed for the military, it was Top Secret. Just as radar
is a yawn in any discussion of leading edge technology today, it
was vital to keeping the free world free. It wasn't until after
World War II had ended that infrared scopes found their way
into unclassified articles, but even then the cost was way more
than any non-governmental entity could afford. The Barska IR scope
from Amazon is not a top-end product, but chances are that being
all solid state it performs at least as well as the beast shown
in this article and is much more rugged than the vacuum tube based
1940s design. Note that the Army guy is wearing a backpack just
to hold the battery.
Invisible Light Aids Marksman
Infrared light used in recently revealed wartime development
makes possible lull visibility on darkest nights. Peacetime applications
Photograph shows the sniperscope as it
appears in conjunction with the .30 caliber carbine. Mounted
on the carbine, this unit permits the sniper to locate the
enemy and then fire.
The snooperscope shown is used for signaling
and as a detection device. Fire control officers used this
unit to direct the battery barrages.
Artist's illustration of the type IP25
image tube similar to that used in this unit.
One of the many secret weapons developed by the U. S. Army during
the war has now been released. This device, employing invisible
light, made it possible for U. S. Infantrymen and Marines to locate
infiltrating troops during the hours of total darkness. This seemingly
impossible feat is accomplished by means of an infrared light beam
and an electronically operated telescopic sight which together convert
an invisible image into a clearly discernible "picture".
This infrared instrument was used in two different ways, the
specific application being more or less indicated by the name applied
to each unit, i.e., the sniperscope and the snooperscope.
The sniperscope was mounted on a .30 caliber carbine and was
used to locate the enemy for direct annihilation by the user. Under
infrared radiation the target became clear, enabling the sniper
to fire on the enemy who had the misfortune to be in the area scanned
by the scope.
The infrared source resembles a fog light in appearance. The
glass face of the unit looks like it is painted black. This part
of the device is mounted below the barrel of the carbine. The other
integral part of the instrument, the telescope, is mounted above
the rear sight of the carbine. The entire unit, both infrared source
and telescope, is connected by means of a cable conductor to a small
power supply which is carried on the sniper's back in a canvas case.
The field operation of the sniperscope is extremely simple. A
fighter armed with a carbine equipped with this device has only
to aim in the general direction of the infiltrating enemy, sight
through the telescope and turn on the power supply. He then moves
the weapon back and forth across the field like an invisible searchlight
until the enemy is sighted. Through the sniperscope the enemy appears
to be spotlighted in a light beam of greenish hue. (Through the
telescope all objects appear in various shades of green regardless
of their natural color). The soldier focuses his telescope to give
the clearest image and then presses the trigger of his carbine and
another Jap has gone to join his "honorable ancestors".
The snooperscope is similar to the snipers cope but the unit
is not used in conjunction with a carbine.
The telescopic device is mounted on a hand grip with the infrared
unit mounted directly below the telescope. This unit is similarly
powered by a portable power supply carried on the back. The snooperscope
was used to direct gun fire and for signaling.
The operating principle of this "night sight" is a combination
of electronics and optics and depends on phototubes with associated
filters to cut out visible light and transmit only the infrared
portion of the spectrum. The telescope receives reflected invisible
infrared images at the front end and converts this radiation into
visible images which are received at the eyepiece.
For the eye to view the scene illuminated by infrared, a specially
constructed electronic tube, similar to the 1P25 image tube, is
used. It operates as a combination "iconoscope-kinescope." The optical
system projects the incoming infrared radiation upon a photo cathode
in the "iconoscope" end of the tube. As this screen is sensitive
to the infrared light, it emits electrons upon being exposed to
such radiation (a photo physical reaction). These electrons, in
an electronic image of the scene illuminated by the infrared, pass
through a series of electrodes of varying potential and strike a
fluorescent screen in the "kinescope" section of the tube in such
a manner that the human eye can see a greenish picture of the original
scene. The electron lens systems and the accelerating electrodes
increase the sensitivity of the tube, and cause the picture on the
fluorescent screen to be brighter and to have greater definition.
This equipment, when available for civilian purposes, will have
several interesting applications. It can be used as a navigation
device for ships and other surface craft thus permitting officers
and lookouts to see a considerable distance with less eye fatigue
on the darkest nights. Obstacles may be detected at sufficiently
great distances to prevent collisions. Other vehicles can also be
operated in complete darkness with safety. During the war the Army
tested this equipment in connection with the operation of locomotives
during the hours of darkness.
Top picture shows a street scene as viewed by the naked eye during
the night hours. The bottom picture shows the same scene as viewed
through the sniperscope. The figures which appear white in the picture
actually have a greenish cast when viewed by the sniper. Clarity
of details enables sniper to score direct hit.
In spite of the fact that this equipment was revealed to the
public only a short time ago, several police departments have expressed
an interest in the infrared "night sight" as a crime detection and
Undoubtedly other peacetime uses for this unit will be found,
where it will augment or replace certain radar applications, but
until more extensive civilian tests are made, this weapon stands
as a tribute to American ingenuity and "know-how".
Posted April 12, 2015