1PN51 ( rus, 1ПН51) is the

GRAU index The Main Missile and Artillery Directorate of the Ministry of Defense of the Russian Federation (), commonly referred to by its transliterated Russian acronym GRAU (), is a department of the Russian Ministry of Defense. It is subordinate to the ...

for a Soviet designed passive night scope for a range of Soviet designed

small arms A firearm is any type of gun designed to be readily carried and used by an individual. The term is legally defined further in different countries (see Legal definitions). The first firearms originated in 10th-century China, when bamboo tubes ...

and

grenade launchers A grenade launcher is a weapon that fires a specially-designed large-caliber projectile, often with an explosive, smoke or gas warhead. Today, the term generally refers to a class of dedicated firearms firing unitary grenade cartridges. The most ...

. ''1PN'' is the GRAU index of night vision devices, where PN stands for ''Nochnoy Pritsel'' ( rus, Ночной прицел) meaning night sight. The scope weighs 2.1 kg and measures 276 mm × 210 mm × 140 mm (length × height × width). It is attached onto a matching side rail on the weapon after which a lever on the scope is pressed to hold it in place. The 1PN51 comes in a metal container with room for extra batteries, battery charger and the other accessories, weighing 6.45 kg in total.

Optics

The scope gathers light via an 80 mm

aperture In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane. An ...

into a reflector with the

secondary mirror A secondary mirror (or secondary) is the second deflecting or focusing mirror element in a reflecting telescope. Light gathered by the primary mirror is directed towards a focal point typically past the location of the secondary. Secondary mirro ...

obscuring the central 42 mm of the aperture. For zeroing the sight the top of the scope has two perpendicular knobs, of which the elevation knob has a detachable scale. The scope comes with eight different, detachable elevation scales for the supported weapons. The aperture cover itself has two 12 mm apertures that can be opened partially allowing the scope to be used in light conditions that would otherwise saturate the light intensifier. The rear end of the scope is a focus dial. The eyepiece has a detachable soft rubber eyecup. The scope has a magnification of 3.46.

Light Intensifier and Reticle

On the left below the aperture the device has a brightness knob. Apart from powering on and off the device, this knob controls the brightness of the

reticle A reticle, or reticule also known as a graticule, is a pattern of fine lines or markings built into the eyepiece of an optical device such as a telescopic sight, spotting scope, theodolite, optical microscope or the screen of an oscillos ...

allowing for the reticle to be visible without outshining the target. The reticle has markings that match targets of various heights from 0.3 m to 2.7 m at distances ranging from 100 m to 970 m. This is similar to the reticle of the

1PN58 1PN58 ( rus, 1ПН58) is the GRAU index for a Soviet designed passive night scope for a range of Soviet designed small arms and grenade launchers. ''1PN'' is the GRAU index of night vision devices, where PN stands for ''Nochnoy Pritsel'' ( rus, Н ...

Power

The light intensifier is powered by a pack of 5 D-0,55S ( rus, Д-0,55С) rechargeable cells, providing up to 7 V. The scope requires 6.25 V. The maximum current drawn is 40 mA. The D-0,55S battery pack is used by a range of devices including

1PN51-2 1PN51-2 ( rus, 1ПН51-2) is the GRAU index for a Soviet designed passive night scope for the RPG-29 rocket launcher. ''1PN'' is the GRAU index of night vision devices, where PN stands for ''Nochnoy Pritsel'' ( rus, Ночной прицел) meanin ...

and 1PN58 and has a separate charging device. The charging device has a switch to select one of 12 V or 27 V input and two red control lamps, one to indicate that power is available and one to indicate that charging is complete.

Supported Weapons

As of 1992 the 1PN51 can be used with the following weapons (weapons on the same line share the elevation scale): SVDN-1, AK-74N (AKS-74N), PKMN-1 (PKMSN-1), RPG-7N1 (RPG-7DN1), AKMN-1 (AKMSN-1), RPK-74N (RPKS-74N),

AKS-74UN The AK-74 (Russian language, Russian: , Romanization of Russian, tr. ''Avtomat Kalashnikova obraztsa 1974 goda'', Literal translation, lit. 'Kalashnikov assault rifle model 1974) is an assault rifle designed by small arms designer Mikhail Kala ...

(no elevation scale), RPKN-1 (RPKSN-1),

VSS Vintorez The 6P29 and 6P30 ( GRAU Indices), commonly known as the VSS "Thread Cutter" (Russian: ВСС «Винторе́з» Винто́вка Сна́йперская Специа́льная, romanized: ''Vintóvka Snáyperskaya Spetsiálnaya "Vint ...

AS Val The 6P29 and 6P30 ( GRAU Indices), commonly known as the VSS "Thread Cutter" (Russian: ВСС «Винторе́з» Винто́вка Сна́йперская Специа́льная, romanized: ''Vintóvka Snáyperskaya Spetsiálnaya "Vint ...

AK-103N2 The AK-103 is a Russian assault rifle designed by small arms designer Mikhail Kalashnikov. History The AK-103 was officially offered for export in March 1993 Design details It is an AK-100 derivative of the AK-74M that is chambered for t ...

(AK-103N2).

Image gallery

File:NSPU-3 at Tula State Museum of Weapons (cropped).jpg, A 1PN51 with its aperture cover set to open mounted on a weapon File:1PN51-2 Battery (4 of 5).jpg, Three battery packs for the 1PN51, two of which are disassembled File:1PN51-2 Set (1 of 5) (cropped).jpg, Battery charger for the 1PN51

References

*{{cite book, title=ИЗДЕЛИЕ 1ПН51 ТЕХНИЧЕСКОЕ ОПИСАНИЕ И ИНСТРУКЦИЯ ПО ЭКСПЛУАТАЦИИ , trans-title= PRODUCT 1PN51 TECHNICAL DESCRIPTION AND OPERATING INSTRUCTIONS, date= January 1992 , no-pp=yes, pages= 48 pages, language= ru Military electronics of Russia Night vision devices