TVS-2B Night Vision Scope MX-7794B
Crew Served Weapon Night Sight
© Brooke Clarke 2005 - 2008
What Goes Wrong
1100BA Battery Adapter
This is a Vietnam era Crew Served
Weapon Night Vision Device. It uses a Schmidt-Cassegrain
system. The manual says 7 power. The objective
diameter is probably 5.5 to 6 inches.
Marked: Image Intensifier, Type:
MX-7854/UV, FSN 5855-051-2702, U.S. Property, Ser. No. 17452, 8524
2.74" diameter x 7.3" long. 34mm flat exit diameter. 1.4"
dia. flat fiber optic plate.
Marked: Oscillator H.V.,
M?052374B(F10), Lectrospace Co., Westbury, N.Y., Contract No., DAARC7-69-C-032,
The oscillator has a socket on it's bottom that plugs directly into a
pin on the image intensifier.
Turning the Focus knob clockwise moves
the main mirror back
Lens Cap - Filter
The front cover
contains a small open segment and a filter wheel with 3
neutral density filters, each more dense than the prior one as well as
an open window. This would allow testing the scope in the
daytime. Using the darkest filter on a cloudy day is about the
same as no cover at night with 1/2 moon on distant hills.
This sight is intended for use on
either the M2 .50 cal. Machine Gun (M2 rtucule) or the 106 mm
Recoilless Rifle (M40 reticule).
This on is setup with the M2 reticule and straight through
eyepiece. When the M40 reticule is used the right angle eyepiece
The reticule gets it's electricity from a cble that goes into the front
of the front lens element. This is not a high voltage wire.
The switch with the pointer has 3
positions. CCW is OFF, then scope ON, then Scope and Reticule ON.
The large knob controls objective focus and the eyepiece controls
focusing on the image intensifier tube output window.
When looking up at the stars at night there's a much larger number of
start visible than with the naked eye. Also there is no night
adaptation of the eye needed since the scope has a bright output.
But you probably can see fainter stars with night adapted eyes.
The output color is green to match the peak in a human eye's spectral
This scope was not intended to be hand held, and doing so is very
difficult. Need to figure out a way to get it mounted on a tripod.
Upon receipt the unit appeared to be
DOA. The 1½" diameter knob on the top of the scope gives
access to the oscillator, which can simply be lifted out.
Plugging it in and removing it a few times cleaned it's contacts and
now it's working OK. It again failed to start and cycling the
oscillator up and down a couple of times fixed it. Maybe it needs
cleaning with a pencil eraser?
battery was the BA-1100/U
6135-00-926-0827 which is one of the long obsolete Mercury based
prior owner has made a simple battery adapter by taking a four "AA"
battery holder where all the cells are wired in series and attaching a
metal plate to each end. The "battery" goes into the scope
Positive (+) end first. The scope case is a negative ground.
The 4 AA battery holder has both the + and - terminals on the same
end. This adapter is made by placing a metal plate on the
terminal end with the positive contact connected to the positive
terminal and with epoxy or hot melt glue insulating the negative
contact. A diode is connected from the negative spring to the
opposite end and goes through a small drilled hole to the negative
metal plate that is glued to insulate it from the jumper eyelets on
end. Single sided PCB material would be a good material to use
The BA-1100 used 4 Mercury cells which when fresh put out 4 * 1.35 =
5.40 Volts. When dead it was 5.0 volts.
If 4 AA rechargeable batteries were to be tried they would be about 1.4
V * 4 = 5.6 Volts fresh and 1.2 * 4 or 4.8 when dead. So although
they probably would work when fresh, the useful life would be short.
If 4 AA Alkaline cells are used the fresh voltage would be 4 * 1.52 or
6.08 which is a little too hot, that's why the diode is in the adapter
to drop the fresh voltage down to about 5.6, very close to the Mercury
battery. The 5.0 volt dead voltage for the adapter occurs when
the cell voltage is 1.4 so when the AA cells no longer work in this
adapter they would still power a flashlight.
1100BA Battery Adapter
After working with the Battery Eliminator (see below) it's clear that
6.6 Volts DC is OK so the diode used in the above battery adapter is
really not needed and not desired since it wasts energy. The 1100BA product
does not use a diode.
The brass disk contacts have polarity (+) and (-) stamped into
them. Also the label "TVS2 cap Positive" is on the Positive end.
This is a battery eliminator that replaces the BA-1100/U Mercury
battery that's long obsolete. It's line powered from regular 115
VAC single phase power.
Converter for Night Vision Sights
AN/PVS-2, AN/PVS-2A or AN/TVS-4
Input: 115 VAC single phase 60 Hz
Output: 6.8 VDC
shown with pin A next to wide keyway
at top. Letters go clockwise.
|DC output is
The A.C. cable will use a MS3116E-14-5S or MS3116F-14-5S or
The MS3116E-14-5S is the lowest
cost and is available from William Perry Co
Wiring is A.C. line to pins B and C.
Earth ground to pin E = threads on battery eliminator and connector
Open circuit output about 6.6 Volts.
Although only three Night Vision Sights are listed on the batery
eliminator it should work for anything that uses the BA-1100/U like the
These are available from Mike
on his NIGHT VISION,
SURVEILLANCE AND RELATED ITEMS web
TM 11-5855-202-10 If you have a pdf let me know
TM 11-5855-202-23P Organizational and Direct Support Maintenance
Repair and Special Tools Lists (Including Depot Maintenance Repair
Parts and Special Tools) For Night Vision Sight, Crew Served Weapons
AN/TVS-2 (NSN 5855-00-087-3144), AN/TVS-2A (NSN 5855-00-791-3358) and
AN/TVS-2B (NSN 5855-00-484-8638)
Night Vision Sight, Individual Crew Served Weapon AN/PVS-2 (NSN
5855-00-087-2947), AN/PVS-2A (5855-00-179-3708) and AN/PVS-2B
TM 11-5855-203-13 Organizational and DS Maintennance Manual, Night
Vision Sight: Crew Served Weapons Models 9927 and 9927A, April 1967
TM 11-5855-203-23P Technical Manual Organizational and Direct Support
Maintenance Repair Parts and Special Tools Lists (Including Depot
Maintenance Repair Parts and Special Tools) for Night Vision Sight,
Crew Served WeaponsAN/TVS-2 (NSN 5855-00-087-3144), AN/TVS-2A (NSN
5885-00-791-3358) and AN/TVS-2B (NSN 5855-00-484-8638), November
1977 Change 1
TB 11-5800-212-24 Procedure for Determining Serviceability of Night
Individual Served Weapon Sight, Crew Served Weapon AN/PVS-2 and
AN/PVS-2A; Night Vision Sight, Crew Served Weapons AN/TVS-2B; Night
Vision SIghts, Mimiaturized AN/PVS-3 and AN/PVS-3A; and Night Vision
Sight, Tripod Mounted AN/TVS-4 and AN/TVS-4A.
TC 23-13 Crew-Served Weapon, Night Vision Sight, Jan 1967
Night Vision Patents
3454773 BINOCULAR NIGHT TELESCOPE WITH
SINGLE IMAGE TUBE, Bulthuis et al (NV Optische), Jul 1969,
3744872 BINOCULAR WITH IMPROVED PRISM MOUNT, Akin (Bushnell), Jul 1973,
- moulded plastic body
4030047 Opto-mechanical subsystem with temperature compensation through
isothermal Design, F.E. Goodwin (NASA), - Beryllium
4205894 Hermetically sealed binoculars, (Bell & Howell) - single
4463252 Night vision goggle system, (Baird Corp), - single objective
5029963 Replacement device for a driver's viewer (ITT), - upgrades the
AN/VVS-2 to a Gen III device
5084780 Telescopic sight for day/night viewing, (ITT), - single
objective, single eyepiece, two internal paths
4822994 Small arms sight for use during
daylight and nighttime conditions, (ITT) - removable image intensifier
Photoelectricity and Its Applications",
1949, John Wiley & Sons Chapter 18 Light Beam Signalling &
4629295 Night vision instrument with electronic image converter (Simrad
Optronics A/S) - beam splitter
3509344 DEVICE WITH A NIGHT TELESCOPE (NV Optische) - two objectives
4467190 Night-vision equipment, Aug 21, 1984
4576432 Aiming or sighting apparatus with synchronously rotating
thermal imager and aiming head Mar 18, 1986
4629295 Night vision instrument with electronic image converter Dec 16,
4653879 Compact see-through night vision goggles Mar 31, 1987
4655562 Objective lens system, relay lens system, and eyepiece lens
system for night-vision goggles Apr 7, 1987
4775217 Night vision viewing system Oct 4, 1988
4828378 Night vision viewing systems May 9, 1989
4863269 Weapon sights Sep 5, 1989
4867549 Re-imaging optical system Sep 19, 1989
5157553 Collimator for a Binocular Viewing System -
5223974 Collimator for a Binocular Viewing System -
5301060 Optical element (Minolta) - laser scanner
5347397 Diopter cell assembly for a
binocular viewing system (ITT) - splitter for single objective two
5444568 Consumer night vision viewing device
5455711 Magnification lens coupling device for a night vision assembly
(ITT) - two adapter rings to add accy lens to NVD
5495364 Night vision binoculars (ITT) - waterproof single objective two
5471374 Illuminator bracket for a night vision device (ITT) - breaks
5495364 Night vision binoculars (ITT) - waterproof single objective two
5537261 Night vision binoculars (ITT) - commercial low cost single
objective two eyepiece waterproof
5595435 Flashlight illuminator for a night vision device (ITT) -LED or
Laser Diode - fits the easily broken bracket (viewer may be the
5737131 Night vision monocular (ITT) -
5847868 Night vision binoculars (ITT) - single objective two eyepieces
6069557 Automatic long-life infrared emitter & locator system -
flashing IR LED beacon (like the one that fits a 9V battery - many
6219250 Night vision binoculars (ITT) - single objective two eyepieces
6456497 Night vision binoculars (ITT) - single objective two eyepieces
6570147 Color night vision apparatus (ITT) - RGB are split like for a
TV camera, seperate Intensifiers work on the three paths where the
output phosphor is the same color as the path color and then combined
H1599 Synthetic-color night vision - blends a visible color image and
an IR image into a single false color image
Fort Belvoir Army Night Vision Labs
- Early Attempts at
Night Vision Technology - 1967 - Pulse Gated I2-TVS-2 Crew Served
Weapon Night Sight
of the United States Army Communications-Electronics Command
(CECOM) - "Second generation night vision devices (image
replaced the first generation "sniper scope" (near infrared
technology) of World War II. The Small Starlight Scope AN/PVS-2, the
Weapons Sight AN/TVS-2, and the medium range Night Observation Device
all saw service in Vietnam. The Night Vision Laboratory, which was
ECOM in 1965, began their development in 1961. Production of the
- Night Vision dealer
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