SP - 1
SPECIFICATIONS OF MARINE RADAR
MODEL 851 MARK-2
1. GENERAL
(1) Indication System
PPI Daylight display, raster scan, 4 tones in monochrome
(2) Range, Pulse Length (PL) & Pulse Repetition Rate (PRR)
Range (nm)
Pulse Length (
µ
s) PRR
(Hz
approx.)
0.125 to 1.5
0.08
2100
1.5 to 3
0.3
1200
3 to 48
0.8
800
(3) Range Resolution
32 m
(4) Bearing Resolution
2.7
º
(5) Minimum Range
27 m
(6) Bearing Accuracy
Within ±1
º
(7) Range Ring Accuracy
1 % of range or 8 m, whichever is the greater
2. SCANNER UNIT
(1) Radiator
Slotted wave-guide array
(2) Polarization
Horizontal
(3) Antenna Rotation Speed
24 rpm nominal
(4) Radiator Length
100 cm
(5) Horizontal Beamwidth
2.4
°
nominal
(6) Vertical Beamwidth
25
°
nominal
(7) Sidelobe Attenuation
less than -24 dB, -30 dB outside of main-lobe
(8) Bearing Wind
51.5 m/s (100 knots) relative
3. TRANSCEIVER MODULE
(1) Frequency and Modulation 9410 MHz
±
30MHz (X band), P0N
(2) Peak Output Power
4 kW nominal
(3) Modulator
FET Switching Method
(4) Intermediate Frequency
60 MHz
(5) Tuning
Automatic
(6) Magnetron
MG5248 or E3571/E3571A
(7) Receiver Front End
MIC (Microwave IC)
(8) Bandwidth
10 MHz
(9) Duplexer
Circulator with diode limiter
(10) Time of Heat-up
90 seconds approx.
