| Radar Equipment | |
| Radar Timeline 1904: 30 April. The "telemobiloscope" (radar) patented and demonstrated by German engineer Christian Hülsmeyer. Telefunken refuses to buy his patents. 1916: February. German Richard Scherl produced the 10cm wavelength "Strahlenzieler" (Raypointer). German Navy rejects it as "not important tot he war effort." 1920s: British Dr. Robert Watson-Watt discovers the theory of radar just after WW I while trying to find a way to detect thunderstorms. 1933: Germany develops the "seetakt" carrier wave (CW) radar that operates at 50 centimeters on 50 watts. It can detect a 500 ton ship at over 7 miles. It is used exclusively as a range finder. 1934: Naval Aircraft Radio Lab produces a pulsed radar that detects aircraft at one mile. 1934: Dr. Robert Watson-Watt produces a radar operating at the 50 meters that can detect an aircraft at ranges of over 80 miles by bouncing the radar off the ionosphere. 1935: September. Germans mount first naval radar on "Welle", operating at 48cm. 1936: Germans produce the Freya surveillance radar operating at 125 Mhz. 1937: British begin installing "Home Chain" defense radar operating at 27.5 Mhz.. 1937: Germans install Freya chain along their North Sea coast. 1937: Naval Research Laboratory installs a 200 mhz radar set on the 5"/38 guns of the USS Leary that can detect targets at 16 nautical miles. The antenna measures 10' x 10'. 1938: Germans field the "Seetaktisch Gerät" (Tactical Sea Instrument) operating at 375 khz (80cm), that can detect a target at 11 miles. It is used as a range finder on Admiral Graf Spee. 1938: British invent the ring oscillator, an important component of more powerful radars. 1938: British detect targets at 100 miles, the Americans 25 miles. 1938: USN equips the USS Leary with a radar operating at 1.5 meters detecting aircraft at 100 miles. 1939: Americans install the "XAF" radar operating at 1.5 meters on the USS New York. It has a "bedspring" antenna measuring 17 feet square and is sensitive enough to detect the splash (fall) of artillery shots. Renamed the "CXAM", the USN orders 20 more. 1939: By May British install a radar operating at 1.5 meters on aircraft and detect ships at 5 miles. 1939: November. British invent the cavity magnetron, allowing microwave radar development. 1940: SC radar operating at 50 centimeters is installed on most US ships. 1941: German Telefunken introduces "Wurtzburg," an improved radar operating at 570 Mhz. 1941: Fire Direction radar is added to the Mk 37 fire director on 5" guns. 1941: Microwave Surface Search Radar model SG radar is fielded. 1941: Late in the year PPI is fielded, greatly improving radar accuracy and usefulness. 1943: Most US Destroyers and Cruisers have SG radar and Fire control radar, allowing them to find "blind" at targets beyond the horizon in any weather conditions. 1943: August. Germans discard "Metrox" and issue the "Hagenuk" radar detectors to their U-Boats, later to replace it with an improved "Naxos" and more sensitive "Fleige". German submarines received their first radar, the "Hohentweil." 1943: Americans field the 10 Ghz surface vessel radar. Germans counter with the "Muecke" detector. 1944: Allied ships are fitted with the SR radar able to detect aircraft 150 miles away. Most ships already have the SC radar (air and surface warning radar). 1944: In October, U.S. Forces detect Japanese ships and destroy 1 battleship, damage 1 battleship, and sink 2 destroyers at a range of 36,000 yards. U.S. Battleships open fire at 22,800 yards, sink the damaged battleship and heavily damage a cruiser. The battle was fought and won entirely with radar! This was the first video war. |
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| TRIVIA:
In 1940-41 radar and electronic warfare were new technologies,
understood by few. There was no civilian counterpart to this technology
and no convenient labor pool the military could tap into for
technicians. The Navy produced a number of recruiting posters to entice young men to enlist for radar training. These are two examples I was able to locate, although I am sure there were many more.
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| December 7, 1941. 0700 hours. At
a lonely outpost on the Northern Shore of Oahu, Privates Joseph L.
Lockard and George A. Elliott, were operating a new, and very secret
radar, the SCR-270-B at an outpost code-named "Station Opana."
At 0702, their oscilloscope displayed an echo they calculated to
be a large flight of airplanes was 132 miles off Kahuku Point and
approaching at a speed of 180 miles per hour. At 0720, they
called the information center at Fort Shafter where Private Joseph P.
McDonald received the call and told Lieutenant Kermit Tyler, who was
newly assigned to the center. An unconcerned Lieutenant Tyler then told
Private Lockard to "forget it" because he had heard a flight
of Army Bombers was coming from the mainland and assumed that was what
the radar station was picking up. Privates Lockard and Elliot continued
to plot and track the incoming aircraft to within 20 miles, where the
surrounding mountains screened the aircraft.
The Japanese air attack on Pearl Harbor began at 0755. |
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| Radar Display (Early). A-Scope: This is a PowerPoint representation of the first radar display, known as the A-scope. Quite difficult to interpret, the first deflection of the scope indicated a "hit" on the target, followed by the second deflection on the range scale. I marked the ranges on the drawing but do not believe they were present on the original A-scope. |
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| Radar Display with PPI. The Plan Position Indicator
(PPI)
display made interpretation of radar images much easier and allowed
simultaneous tracking of multiple targets. The rings indicated the range
of the target and direction of the target. The ship position was always
at the center of the grid.
The bottom picture is of an actual PPI display. National Archives #80-G-414179 |
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| The radar room
on the USS Robinson in October 1949. From left to right, the "A"-scope
(see above) and bearing dial (with coffee and sugar cans on top).
The scope on the right is the PPI scope (also described above).
Note the fade chart on the left. This went with the SA radar.
Courtesy of Adam and May Vanyo. |
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| A radar "cockpit" showing the PPI display and the various control systems. In this display, the cockpit includes the ship jamming system controls. Each of the items in this display are detailed individually below. | 
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| AN/SPA-4B, Azimuth and Range
Indicator, consists of accessories and the following: 1 azimuth and
range indicator, ?D- 3020/SPA-4. Manufactured by: Pacific Division, Bendix Aviation Corporation, North Hollywood, California Contract Number: NObsr71048 |
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| CAY-23AEW, General Control
Panel, a unit of model SRa or SR-5 radar equipment Manufactured by: Westinghouse Electric & Manufacturing Company, Baltimore, Maryland. Contract Number: NOsr-46032 |
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| CAY-46ADH, Receiver Console,
a unit of Model SR radar equipment Manufactured by: Westinghouse Electric & Manufacturing Company, Baltimore, Maryland. Contract Number: NOss-30306 |
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| CAY-55AFB, Range Scope, a
unit of Model SR radar equipment Manufactured by: Westinghouse Electric & Manufacturing Company, Baltimore, Maryland. Contract Number: NXss-30306 |
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| CAY-55AFC, Bearing Indicator,
a unit of Model SR radar equipment Manufactured by: Westinghouse Electric & Manufacturing Company, Baltimore, Maryland. Contract Number: NXss-30306 |
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| CV-69/ULR, Mixer-Amplifier,
a unit of AN/SLR-1 or AN/SLR-2 Manufactured by: Collins Radio Company, Cedar Rapids, Iowa Contract Number: NObsr-54770 |
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| CV-70/ULR, Mixer-Amplifier,
a unit of AN/BLR-1 or AN/SLR-2 Manufactured by: Collins Radio Company, Cedar Rapids, Iowa Contract Number: NObsr-52150 |
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| C-1609/SLR, Control-Indicator,
For Countermeasures Use Manufactured by: Granite State Machine Company, Incorporated, Manchester, New Hampshire Contract Number: NObsr-97340 |
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| AN/SPA-8A, Indicator Group and IP-97B/SPA-8, Azimuth-Range Indicator, a unit of Indicator group AN/SPA-8A Manufactured by: Hazeltine Electronics Corporation, Little Neck, NY Contract Number:NObsr-52313 |
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| Unidentified Radar Control
Panel. No data plate present or description on the front panel. Manufactured by: Unknown Contract Number: Unknown |
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| RT-194/UPX-1, Radar
receiver-Transmitter, a unit of radar recognition set AN/UPX-1 Manufactured by: General Communications Company, Boston, MA Contract Number: NObsr-49224 |
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| Simplified Radar Target
Simulator. Manufactured by: Louisville Machine Company, Louisville, Kentucky Contract Number: N-151-20555-A |
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