Description of the radar set, tactical-technical characteristics
Figure 1: Mk. 4
|pulse repetition time (PRT):|
|pulse repetition frequency (PRF):||1 639 Hz|
|pulsewidth (τ):||1.5 µs|
|peak power:||20 kW|
|average power:||46 W|
|instrumented range:||17 NM (≙ 32 km)|
|range resolution:||360 m|
|hits per scan:|
Mk. 4 was operating in UHF-Band fire control radar. It was used with the gun directors Mk. 33 and Mk. 37 with 5-inch guns.
The antenna consisted of two cylindrical parabolic reflectors, lying one above the other with a row of 4 half-wave dipoles each. The altitude could be determined from the phase difference between the two antenna groups. However, this was only possible from an elevation angle higher than 10° because of the disturbing multipath receiving at lower elevation angles.