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el cid again -> AI Mark IV Radar (Stock Device slot 232) (3/31/2014 10:02:39 PM)
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For reasons unclear this device is given a range of 30 (thousand yards)
instead of 6.
SCR-540 1.5m Radar
American Version of British Mk IV Radar. Manufactured by Western Electric, delivered 1942 for installation in USAAF P-70 (right) and Marine Corps PV-1 (lower right) night fighters. First confirmed combat kill April 19, 1943, 6th NFS, Guadalcanal.
Description
1.55 cm airborne radar for aircraft interception. Weight: 181 lb including cables and inverter. Operators: 1. Power: 40 amp, 27 volt DC. Antenna: fixed quarter wave dipole with directors on side of fuselage (azimuth receiving): 2 fixed quarter wave rods, one above and one below wing (elevation receiving). Indicators: 3-inch CRT with vertical baseline target pips on left and right (azimuth): 3-inch CRT with horizontal baseline, target pips above and below (elevation).
USMC PV-1 night fighter of VMF(N)-531 at Vella La Vella, Solomono Is, 13 Jan 1944Research and Development By
British and Bell Telephone Laboratories
Performance
Max. Range on: Bombers, at 20,000 ft: 6000 yd.
Fighters at 17,000 ft: 4000 yd.
Minimum range: 300 to 500 ft
Range Accuracy: 300 yds.
Angular Accuracy: 10° Elevation 10°
Search
Fixed antenna, targets within forward hemisphere 160° elevation sector may be detected. Effective search range limited to altitude of plane.
Antenna Specifications
Transmitting: Bent folded dipole with director on nose of aircraft. Elevation receiving: 2 fixed quarter wave rods with directors, one above and one below the left wing. Lobe switching at 1750 cycles per minute.
SCR-540 elevation antenna, transmitting antenna, and azimuth receibing antennae on wing of A-20
Anntenna installation on A-20 (prototype P-70), left-to-right: elevation receiving antenna, transmitting antenna, azimuth receiving antenna.
Transmitter Specifications
Frequency: 193 mc/s Pusle Rate (pps): 750 to 850
RF Source: 2 710s push-pull Pulse Rate Beacon: 750 to 850 nps
RF Lines: Coax (solid dielectric) Pulse Legnth: 1.3 µs
Pulser Type: Hard Tube Pulse Length, Beacon: 2.1 µs
RF Peak Power: 10 kw Energy pp, Radar: .013 joules
RF Average Power: .01 kw
Receiver Specifications
Type: Superheterodyne IF Band Pase: 5 mc/s
Stages: O-RF; 4-IF Mixer: 955 tube
Local Oscillator: 955 Noise, db above kt df: 14-16
Intermed. Freq.: 30 mc/s
Indication and Data Output
Operator has indicator with two 3-inch CRTs. Left tube has horizontal sweep with echoes appearing as pips above and below searching plane. Right tube operates similarly but has a vertical sweep with left and right pips indicating whether target is to the left or right of searching plane. Time scales are variable and the distance for a given length of trace depends on control setting. Scale is exponential. Attack range: 1-7 miles. Homing range: 100 miles.
Remarks
Maximum altitutde for satisfactory operation: Approximately 20,000 ft. Operates with SCR-640 homing beacon.
Generally not employed to control an area when prsence of enemy aircrft has not been determined in advance. SCR-540-T2 is similar to SCR-540-A except for minor circuit differences.
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