Help ! Identify Mystery Night-Vision Tube
Jim0123
exactly what it is - or more importantly, how to power it up. I could
make out the following text on the body of the tube :
US
MX-9644/UV
80063 SM-D-850310-1
NSN 5855/00-138-2386
CONTRACT NO DAAB07-76 C/066
MFR NI-TEC 51298
Is this from a PVS-4 sniperscope - I thought those were made
by ITT instead of this 'Ni-Tec' ? In any event, the tube is of
black plastic with a 25mm photocathode window. It is 3.000
inches in length and 2.465 inches in diameter. It has a little
bit of threading back by the phosphor window end.
But now the important part ... near the photocathode end, there
are FOUR connector pins, labled '1' thru '4'. WHAT ARE THEY ?
I presume that two are for the main power (how many volts?)
but I don't know what the other two may be. Any info GREATLY
appreciated ... NO instructions were included with the tube.
--Jim
Gilbert Gwilliam
This tube is the exact equivalent of the ITT tube (actually, a little
better). It was made by a company called NiTec, for which I worked at
the time the tube you have was made (based on the contract number you
quoted.) As to the function of the pins, two are for the power, and the
other two are for the gain control, which is a variable resistance
connected between the two pins. I can't remember which is which (I
_think_ that 1-4 are power and 2-3 are the gain control, but I couldn't
tell you polarity off the top of my head). E-mail me and I will check
with someone who would know.
Jeff Gwilliam
Morris the Cat
|exactly what it is - or more importantly, how to power it up. I could
|make out the following text on the body of the tube :
|US
|MX-9644/UV
|80063 SM-D-850310-1
|NSN 5855/00-138-2386
|CONTRACT NO DAAB07-76 C/066
|MFR NI-TEC 51298
|Is this from a PVS-4 sniperscope -
Probably. The 25mm MCP tubes are also used in the AN/VVS-2 night
driving periscopes as well.
I wonder if "07-76" denotes a July 1976 manufacture date?
|I thought those were made by ITT instead of this 'Ni-Tec' ?
I don't think ITT ever manufactured the the AN/PVS-4 starlight
scope. The image intensifier tubes were manufactured by ITT and
Varo as well. "NI-TEC" was originally a manufacturer of image
intensifier tubes and AN/PVS-4s located in Skokie, Illinois.
They were having quality control problems in the last year
they were in Skokie, and lost the ability to produce image
intensifier tubes.
They are now located somewhere in Texas, presumably Garland where
Varo was or is.
|But now the important part ... near the photocathode end, there
|are FOUR connector pins, labled '1' thru '4'. WHAT ARE THEY ?
|I presume that two are for the main power (how many volts?)
|but I don't know what the other two may be. Any info GREATLY
|appreciated ... NO instructions were included with the tube.
Two of the connector pins are intended to be bridged by a variable
resistor that is the "Gain" control seen on the PVS-4, I believe.
(Probably the middle two, but I will have to check the manufacturer's
spec sheets)...
Morris the Cat
|exactly what it is - or more importantly, how to power it up. I could
|make out the following text on the body of the tube :
|US
|MX-9644/UV
|80063 SM-D-850310-1
|NSN 5855/00-138-2386
|CONTRACT NO DAAB07-76 C/066
|MFR NI-TEC 51298
|Is this from a PVS-4 sniperscope - I thought those were made
|by ITT instead of this 'Ni-Tec' ?
Yes, this is the tube to the PVS-4 starlight scope.
The specifications for the Varo equivolent model (3603-1, 3603-2)
are:
(Date: 6-1980)
Operating Voltage: 2.65V DC
Min. Resolution (center): 28 line-pairs/mm
(Off center): 25 lp/mm
Magnification: .96 to 1.04
Gain: 30,000 min (3603-1); 25,000 min (3603-2)
Photocathode: S-20ER
Cathode sensitivity: 240 microamps/Lumen (3603-1);
200 microamps/Lumen (3603-2)
Phosphor: Aluminized P-20
EBI: 2 * 10E-11 Lumens/ Square cm (3603-1);
3 * 10E-11/ Square cm (3603-2)
MTF: (3603-1) @ 2.5 lp/mm: 90%, @ 7.5 lp/mm: 60%, @ 15 lp/mm: 25%
(3603-2) @ 2.5 lp/mm: 90%, @ 7.5 lp/mm: 55%, @ 15 lp/mm: 20%
|In any event, the tube is of
|black plastic with a 25mm photocathode window. It is 3.000
|inches in length and 2.465 inches in diameter. It has a little
|bit of threading back by the phosphor window end.
Threads are: 2.480-28 UNS-2A
|But now the important part ... near the photocathode end, there
|are FOUR connector pins, labled '1' thru '4'. WHAT ARE THEY ?
|I presume that two are for the main power (how many volts?)
|but I don't know what the other two may be. Any info GREATLY
|appreciated ... NO instructions were included with the tube.
The Varo schematic diagram has this caveat:
-------------------------------------------------
CAUTION
For proper operation, the image intensifier must
be connected as indicated in this diagram.
-------------------------------------------------
Pin 1 is the POSITIVE input (+ 2.5V DC)
Pin 2 is for the MANUAL Gain Control
Pin 3 is for the MANUAL Gain Control
Pin 4 is the System Ground
The extra electrical components needed are: "ON/OFF Switch Poteniometer
(50 Kiloohms)," and a 470K fixed resistor.
The switch on the pot is placed in series with the POSITIVE (Pin 1)
pin. (The ITT specificiations claim a 17ma current drain.)
For Clockwide Minimum to Maximum Gain, the Wiper of the 50K pot connects
to Pin 2. The pot connection at the end of the CW travel goes to
Pin 3. The pot connection at the beginning of the CW travel is connected
to the 470K resistor, whose other end is at the System Ground
potential.
Let us know how the unit turns out!
I've looked at these tubes longingly for about 15 years, but no way
could I afford one...
|--Jim
Morris the Cat
|US
|MX-9644/UV
|80063 SM-D-850310-1
|NSN 5855/00-138-2386
|CONTRACT NO DAAB07-76 C/066
|MFR NI-TEC 51298
|This tube is the exact equivalent of the ITT tube (actually, a little
|better). It was made by a company called NiTec, for which I worked at
|the time the tube you have was made (based on the contract number you
|quoted.)
[Was Ni-Tec ("Night Technology" Corporation) the old Zenith
Electro-Optical company?]
The 9/77 Ni-Tec Image Intensifier brochere states that the R6340 25mm
MCP tubes, which the "500D0021" is stated to be "25mm inverter tube
package with mechanical design equivalent to United States Army
configuration."
The text states that it utilises an S-25 photocathode; were all the
Ni-Tec 25mm MCP tubes delivered with S-25 rather then S-20 Extended Red
photocathodes that the other manufacturers used?
The specs given for this Ni-Tec tube seem a bit better than the Varo
equivalent:
25mm Inverter R6340 (Typical)
Photocathode sensitivity: @ 2856 Kelvin (microamps/lm) -- 300
Luminous Gain: 45K
Resolution:
(Center) -- 32 lp/mm
(Edge) -- 28 lp/mm
Magnification:
(Center) -- .98
(Edge) -- 1.00
Distortion: 2%
EBI at 23 Celsius: 1 * 10E-11 Lumens/ Square CM
MTF: @ 2.5 lp/mm: 92%, @ 7.5 lp/mm: 64%, @ 15 lp/mm: 28%
|Jeff Gwilliam