SOV - 5N91 / P-90 Pamir (3D rádiolokátor)

The P-90 radar is designed to detect air targets and to guide its own fighters. The radar detects three coordinates, azimuth, oblique distance and height of the target, it works in the decimeter band of the waves.


Basic parameters:
MiG-17 fighter detection distance/altitude detection distance:

Target detection upper limit: 50 km
Development time at the prepared site: 15 days



Source: www.vko.ru

The antenna system together with the rotation system (APU-antenno-povorotnoe ustrojstvo) was placed on a reinforced concrete structure. Furthermore, there were parts of the antenna-waveguide path, receiving and transmitting containers, transmitters of synchronous servo transmission of rotation together with a block of transmission of azimuthal marks, power parts of rotation and with a current collector.
The large weight of the antenna part (130 tons) also required a special construction of a reinforced concrete base, an oporno-rotating device (OPU-oporno-povorotnoe ustrojstvo), which ensured the rotation of the antenna at a speed in the range (2.5 - 5) rpm.
The other equipment was placed in trailers and containers. The P-90 set also included a 110-meter mast, which was placed 2 km from the radar and was used to adjust the antenna systems.
The antenna-rotating device (APU-antenno-povorotnoe ustrojstvo) consisted of two identical antenna systems, placed on a supporting-rotating device, which operated in the whole band of operating frequencies. Each antenna system consisted of a transmitting and receiving antenna, a recognition antenna, and an active fault suppression system antenna.
The transmitting antenna consisted of a waveguide emitter and a double-curved reflector measuring 13.5x5m, mass-produced machines had an antenna measuring 13.5x7m.
The receiving antenna consisted of a parabolic mirror measuring 18x15 m and a multichannel radiator, shaping 21 partial directional characteristics (diagrams) in the vertical plane. The width of the characteristic of the first eight channels in the vertical plane was 1 degree, widening upwards, and in the 21st channel it was 3.5 degrees. The performance characteristics of adjacent reception channels overlapped at half the power level. For mass-produced radars, the number of receiving channels was increased to 24.
The antenna of the active interference suppression system was designed as a plane emitter with an asymmetric parabolic reflector, in the vertical plane the directional characteristic covered angles ranging from 0.5 to 25 degrees. In the horizontal plane, the directional characteristic overlapped the maximum levels of the side loops of the directional characteristic of the receiving antenna.
The transmission system consisted of a crystal stabilized control generator, a frequency multiplier operating in pulse mode, a modulator and a power cluster amplifier. The power of the transmitter was 2.7-3 MW. There were four transmitters in the P-90 radar, two for each antenna system. For the first time, new components were used in the transmitting device, a 3MW power amplifier-klystron with liquid cooling, in a modulator commuting a thyratron.
The receiving device had 42 receivers (21 channels x 2 antenna systems), the receivers were two-channel, designed for simultaneous reception, amplification and processing of signals of two frequencies: A and B for the first antenna, G and D for the second.
The air situation was displayed on three types of indicators: the IKO circular horizon indicator, the IAD "azimuth-distance" indicator and the IV height indicator. All indicators were placed in one cabinet, the radar had 7 indicator cabinets.

View of part of the instrument trailers

Source:www.vko.ru

view of cabinets with indicators

The following photos are from www.vko.ru

The following diagrams are from www.vko.ru

Additional information to images Pamir_14_vyzar_diag.jpg and Pamir_15_vyzar_diag.jpg:

- both diagrams used for comparison due to the stíhacímu of the MiG-17

- orange outline - MiG-17

- blue contour - fighter aircraft T-3

- pink contour - bomber aircraft Tu-16

- the other descriptions are not, unfortunately, read


Additional information to images Pamir_16_vyzar_diag.jpg and Pamir_17_vyzar_diag.jpg:

- red outline - dvoufrekvenční mode when tau = 1 mikrosekunda

- green contour - single-frequency mode when tau = 3 microseconds

- blue contour - dvoufrekvenční mode when tau = 3 microseconds.