SCR Series Radars

SCR-268

(Drawing of SCR-268-B)

Type of Radar: Semi-Mobile Air Search Radar
IEEE Band: G Band
NATO Band: A Band
Exact Frequency: 205 MHz
Power: 75 kW
Minimum Range: 3,000 yards
Maximum Range: 50,000 yards
Range Accuracy: +/- 200 yards
Altitude Accuracy: +/- 100 yards
Azimuth Accuracy: 10 mils
Angular Accuracy (above 350 mils): 10 mils

Transportability: Equipment is carried in vehicles. Total weight of SCR-268 is 15 tons. Largest vehicle weighs 9 tons and measures 8' x 10⅔' x 18'. total weight of SCR-268-B is 42.6 tons. Largest vehicle weighs 14 tons and measures 8⅓' x 11' x 24¾'. SCR-268 consists of two trailers; SCR-268-B, of a trailer and 4 trucks.

Installation: Thirteen men can install set and obtain approximate data in 2 hrs. Accurate orientation and alignment takes 4 more hours. Orientation and alignment are complex, and must be checked daily. For best results, set should be located on high ground with 100 yards of level clearance all around.

Personnel: Minimum of 5 operators and a Chief Radar Operator are required.

Power: 9 KVA, 120 V, 50-60 cycles AC required. Source is generator (supplied with set). Unleaded gasoline should be used when possible. Consumption is 3 to 4 gal. per hour. Modification kit PE-178 permits operation on commercial power.

SCR-270

(Drawing of SCR-270-D)

Type of Radar: Mobile long wave early warning radar.
IEEE Band: I Band
NATO Band: A Band
Exact Frequency: 106 MHz
Angular Accuracy: 1 degree

Performance (Against Single Bomber Target):

20 miles on target at 1,000 ft
50 miles on target at 5,000 ft
100 miles on target at 20,000 ft
110 miles on target at 25,000 ft

Transportability: Complete set is carried in 6 vehicles, the largest of which measures 30'4" x 9'10" x 8'. Total weight of shipment is 101,790 lbs; total volume 11,485 cu. ft.

Installation: Operates from trucks in which mounted. Can be placed in operation about 6 hours after arrival at site. Set should be sited at a height between 100' and 1000' above an unobstructed reflecting surface.

Personnel: Seven men comprise operating crew. For 24 hour operation about 50 men are required to run radar, communication radio, and camp.

Power: 15.3 KW, supplied by PE-74, 25 KVA gasoline-driven generator, having fixed consumption of 4 gal. per hour, non-leaded gasoline.

SCR-540

(Diagram of SCR-540)

Type of Radar: Air Intercept Radar in aircraft
IEEE Band: P Band
NATO Band: A Band
Exact Frequency: 193 MHz
Peak Power: 10 kW

Performance: Maximum beacon range: 100 miles. Maximum search range, 17,000 to 20,000 ft. Minimum range, 300 to 500 ft. Range accuracy, ± 10%. Azimuth limits, 70° forward on either side of line of flight. (No targets detected at ranges greater than plane's altitude.) Azimuth accuracy: right or left indication only when target is more than 5° from line of flight. Within 5° of line of flight, target will show as straight ahead. Elevation limits (at 20,000' altitude), ± 20° from forward line of flight. Elevation accuracy, same as azimuth accuracy.

Transportability: Set is packaged in 7 units weighing about 225 lbs. Largest package measures 13" x 6" x 26" and weighs 32 lbs. Set is air transportable in any cargo plane.

Installation: Set is installed in P-70, Beaufighters, and A-20's. Installed weight is about 210 lbs.

Personnel: One radar operator and one maintenance man are minimum requirement.

Power: Primary power required: 40 amperes at 27.5 volts from plane's DC supply.

Notes: Design based upon British AI Mk IV. Two "A" type indicators are used, one for azimuth and one for elevation. External antennas provide azimuth and elevation sensing. IFF signals displayed directly on the scope. SCR-540 operates with the SCR-640 racon.

SCR-584

(Diagram of SCR-584)

Manufacturer: General Electric
Type of Radar: Mobile AA Gun Radar
IEEE Band: S Band
NATO Band: E Band
Exact Frequency: 2700 – 2900 MHz
Power: 250 kW
Minimum Range: 500 yards
Maximum Range: 50,000 yards
Range Accuracy:
25 yards
Azimuth Accuracy: 3 mils
Angular Accuracy: 3 mils

Transportability: Set is transported a semi-trailer towed by a 4-ton tractor. One spare parts truck is provided for each AA Gun Battery. Excluding spare parts truck, set weighs a total of 15 tons and occupies 2770 cu. ft. Largest vehicle measures 8' x 10.5' x 19.5'. Spare parts truck (supplied with every 4 sets) weighs 7 tons.

Installation: Can be set up, oriented and synchronized with associated equipment in 30 minutes, using crew of 9 trained men.

Personnel: Two operators and Chief Radar Operator are minimum requirement.

Power: Required peak power of about 12 KVA, 3 phase, is supplied by Gun Battery power plant.

SCR-717

(Diagram of SCR-717-A)

IEEE Band: S Band
NATO Band: F Band
Exact Frequency: 3100-3400 MHz
Power: 150 kW
Minimum Range: 600 feet
Maximum Ranges:

70 miles on 5,000 to 10,000 ton ships
20 miles on surfaced submarines

Transportability: Each set is packaged in 5 units the largest of which measures 24" x 37" x 43" and weighs 177 lbs. Total shipment weighs 773 lbs. and occupies 78 cu. ft.

Installation: Antenna is installed in a retractable belly turret in the B-24 or B-25 replacing the lower gun turret. Remaining components are installed in radio compartment. Total installed weight including operator's seat and retraction gear is 560 lbs.

Personnel: One radar operator and one maintenance man per set are minimum requirement.

Power: Primary power required: 100 amperes at 27.5 volts from plane's DC supply.

Notes: Developed from SCR-517. The -A version has B scopes for the pilot and radar operator with maximum ranges of 5, 20, 50, and 100 nautical miles. Either the forward or rear 180° is scanned as desired. The -B version has PPI scopes for the pilot and radar operator with maximum ranges of 4, 25, 40, and 100 nautical miles. 360° scanning is provided on all ranges, with open center indication on the 4 mile range. Both sets have provisions for IFF, and connectors to operate with IR, racon and AN/APQ-5 Radar Bombsights.

SCR-784

IEEE Band: S Band
NATO Band: E Band
Exact Frequency: 2700-2900 MHz