P-3 “Dumbo”
Description of the radar set, tactical-technical characteristics
Figure 1: The mobile P3M- sersion, (Antenna left)
| Specifications | |
|---|---|
| frequency: | VHF–Band |
| pulse repetition time (PRT): | |
| pulse repetition frequency (PRF): | |
| pulsewidth (τ): | |
| receiving time: | |
| dead time: | |
| peak power: | 55 kW |
| average power: | |
| instrumented range: | 120 km |
| range resolution: | 2.5 km |
| accuracy: | |
| beamwidth: | 24° |
| hits per scan: | |
| antenna rotation: | |
| MTBCF: | |
| MTTR: | |
P-3 “Dumbo”
The first Soviet radar unit to the determination of 3 coordinates was built approximately end of the World War II. The radar station was called “Pegmantit 3” - or abbreviated for P 3. There were two modifications: a mobile (P-3M) and a fixed site (P-3A) version. The mobile version was built in containers on two trucks. The transmitter and and the receiving system were put in a separate container. The display still was an A-scope.
If the display is an A-scope only, this radar cannot rotate quickly. It has to be assumed that the turn was manually carried out (like a direction findig equipment by radio-monitoring). Otherwise the given accuracy in azimuth isn't concurring with the poor antenna gain of a single pair of Yagi-antennas to be expected.
The elevation angle was determined with a so-called Goniometer. With a nomograph the elevation angle could be converted to a height value depending of measured range.
Accuracy:
- of the azimuth determination: 4°
- of the range determination: 1,5 km
- of the height determination: 1,5
Source: G. Nitschke, K.-H. Lau, “Von der visuellen Luftraumbeobachtung zur elektronischen Luftraumaufklärung”
in: “Militärwesen” 7/72 - Ausgabe B (Luftstreitkräfte) Militärverlag der DDR
Figure 2: An artists impression of the fixed site P3A-version