NSB – 4B – Sighting device for mortars 81/82 mm and 120 mm
Sighting device NSB-4B serves for sighting during firing with mortars.It can be used for any type of mortars, if the switching connection between NSB-4B and mortars coordinated.
Vertical and horizontal angles are occupied on appropriate drums and plates.
Vertical and traversals levels, after adjusting, through weapon mechanism give occupied position of tube on the weapon.
Sighting according to the direction is done by the telescope that has the cross on itself for adjusting, with picket or some other position determining the basic direction of weapon.
Technical data:
| Telescope magnification | 1,8 x ± 5% |
| Telescope field of view | 8° ± 5% |
| Diameter of input aperture | 12,7mm |
| Output pupil diameter | 5,5 ± 5% |
| Output pupil distance | 25 mm |
| Diopter adjustment | -0,5 to -1 dpt |
| Possibility of sighting according to height | cca -13° cca +25° |
| Accuracy of horizontal angles NSB-4B | 0-015 |
| Smallest division of distance drum | 1-00 |
| Smallest division of distance plate | 0-01 |
| Accuracy of tabular angles | 0-02 |
| Smallest division of tabular angles drum | 1-00 |
| Smallest division of tabular angles plate | 0-01 |
| Sensitivity of vertical and traversal level | 5-7′ |
| Accuracy of sighting by plummet | 0-015 |
| Turning possibility of telescope for | 90° |
| Sighting device with telescope | 0.8 kg |
| Total weight of NSB-4B in the box with accessories | 3.5 kg |