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Description of the radar set, tactical-technical characteristics

Figure 1: S-669

frequency: S band
pulse repetition time (PRT):
pulse repetition frequency (PRF): 600 or 220 Hz
pulsewidth (τ): 2,5 or 5 µs
receiving time:
dead time:
peak power: 2 × 2,25 MW
average power: 2 × 2,5 kW
instrumented range: 263 NM (≙ 470 km)
range resolution:
beamwidth: 0,6°
hits per scan:
antenna rotation: (16 ±1) min⁻¹


S-669 is operating in the S band heightfinder which was used in the NADGE system.

The antenna consisted of a 12.2 m single curved parabolic reflector fed by an equally long slotted waveguide. The radar may operate with a second transmitter either in stand-by, or in frequency diversity mode on two frequencies. Unfortunately, the advantages of frequency diversity could not be exploited because a frequency change in the waveguide slot antenna caused a change in the radiation angle. Only the accuracy of the localization was negatively affected, which is why only one transmitter was used in practice.

The heightfinder could continuously rotate at about 16 revolutions per minute for a target search in low altitudes. There were also versions reduced in pulse power with only 150 NM (≙ 278 km) range.