FS; MILITARY METASCOPE
Bob
I have a military metascope for sale that was made by Lewyt, Brooklyn, N.Y.
and marked "US/AM Navy No. Nan R-1400" and serial numbered. It has a
rubber eyepiece. It is clean and in perfect cosmetic shape and I don't know
anything about it's operation nor do I care to learn, so I can't make any
claims there. It comes with 2 printed yellow pages describing it. It also
has a matching case and carrying strap with the Lewyt name on it. The case
is in great shape but could use a toothbrush scrubbing to get rid of some
minor storage dirt. Please make a reasonable offer and include an
additional amount for postage. Thanks, Bob
Foramel
>I have a military metascope for sale that was made by Lewyt, Brooklyn,
N.Y.
What's a metascope? Please explain.
I thought I knew already quite a few "scopes":
telescope
microscope
macroscope
endoscope
polariscope
periscope
stereoscope
kaleidoscope
colposcope
ophthalmoscope
bronchioscope...
Well even CinemaScope.
Abandoning greek roots:
nightscope
borescope
All of the above "scope" instruments are based on optics which may
envisaged as a branch of physics.
I will assume therefore for the time being that a "metascope" is based on
metaphysics.
Louis Boyd
Foramel wrote:
>
> >I have a military metascope for sale that was made by Lewyt, Brooklyn,
> N.Y.
>
> What's a metascope? Please explain.
> metaphysics.
Metascopes (at least the one's I'm familiar with) were a low gain
infrared
viewer. Prior to the invention of infrared image converter tubes a
method
was needed for signalling between ships which couldn't be seen with the
eye. The metascope used a ~6" Schmidt f/0.5 mirror & corrector to focus
infrared light onto a screen made of a substance which could be
"charged"
with blue light then it would convert IR into the visible band. The
charger
consisted of a small lamp and four AA batteries. I don't know what the
conversion material was, but it had a curved surface to match the focal
plane of the Schmitd optics and light salmon colored, made of fine
crystals.
There may have been other models from the one I just described which
used
the same principle.
I believe they were used with a special transmitting lamp as I've seen
cesium lamps which were used for signalling. I think these were used
together. I also believe some of the early devices with the 1P25 image
converter tubes also carried the name metascope. Compared to a modern
GenIII image intensifer these devices were very insensitive but they
got the job done. A nice war souvenir.
Lou Boyd
Fairborn Observatory
Morris the Cat
|Metascopes (at least the one's I'm familiar with) were a low gain
|infrared viewer. Prior to the invention of infrared image converter tubes
|a method was needed for signalling between ships which couldn't be seen with the
|eye.
The U.S. military still used the term "Metascope" in describing handheld
infrared night vision devices utilising infrared image convertor tubes
(6929) even into the 1960s e.g. the Polan P-141 and the unit Varo produced
which was powered by a mercury battery (the mil designation escapes me).
|The metascope used a ~6" Schmidt f/0.5 mirror & corrector to focus
|infrared light onto a screen made of a substance which could be
|"charged" with blue light then it would convert IR into the visible band. The
|charger consisted of a small lamp and four AA batteries.
This sounds like the Kodak Model "B" Metascope; if so, you are mistaken as
to the power source; it was TWO AA batteries. The other position on the front
of the unit with the screw cap didn't hold AA batteries, but two dessicant
capsules.
|I don't know what the conversion material was, but it had a curved surface to
|match the focal plane of the Schmitd optics and light salmon colored, made of fine
|crystals.
I don't know what the material was, but they seem to have developed surface
cracks and no longer function. You could probably substitute something from
Radio Shack (small area) or Kodak in lieu of the material. Note that they were
TWO surfaces with the IR conversion phosphor; while viewing with one you could
charge the other with the touch of a pushbutton.
|There may have been other models from the one I just described which
|used the same principle.
There was a smaller handheld version which also used Schmidt optics but
utilised a RADIUM-powered phosphor that apparently quenched upon being
illuminated by IR radiation; U.S. government warehouses that stored these
were literally bathed in the green light of the radium-powered phosphor,
or so I've been told.
|I believe they were used with a special transmitting lamp as I've seen
|cesium lamps which were used for signalling. I think these were used
|together. I also believe some of the early devices with the 1P25 image
|converter tubes also carried the name metascope. Compared to a modern
|GenIII image intensifer these devices were very insensitive but they
|got the job done. A nice war souvenir.
Most likely, all the 1P25 IR image convertor tubes have died from internal
outgassing and leakage, so they won't get the job done nowadays! Those WWII
Metascopes are basically nonfunctioning museum pieces now...
On the other hand, I recently tried a U.S.A.F. ANVIS helicopter night
vision goggle demostration; their performance is literally OUT-OF-THIS-WORLD!
|Lou Boyd
|Fairborn Observatory
yugz...@gmail.com
> I have a military metascope for sale that was made by Lewyt, Brooklyn, N.Y.
> rubber eyepiece. It is clean and in perfect cosmetic shape and I don't know
> anything about it's operation nor do I care to learn, so I can't make any
> claims there. It comes with 2 printed yellow pages describing it. It also
> has a matching case and carrying strap with the Lewyt name on it. The case
> is in great shape but could use a toothbrush scrubbing to get rid of some
> minor storage dirt. Please make a reasonable offer and include an
> additional amount for postage. Thanks, Bob
805anth...@gmail.com
scoo...@hotmail.com
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