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66:(CRT) technology. At the beginning of the 1990s, the outdated panoramic display (using old cathode ray tube technology) needed replacement due to the existing display becoming unsupportable. This replacement was delivered in the late 1990s. At that time, tuners and the power supply were determined to also need replacement for the same reasons. Today, deployed on B-52H bombers, the system still provides the EWO a display of six different RF bands, allowing for detection and identification of threat signals.
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to create up to thirty-fold improvements in reliability. Efforts to replace the ALR-20 continued into the mid-2000s, while some work was done to continue maintaining line replaceable units (LRUs). In 1999, ninety-one LRU-1s, fifty-four LRU-3s, thirty-six LRU-8s, eighty-three LRU-9s were repaired at a total cost of over $ 315,000. According to the Air Force's Fiscal Year (FY) 2004/2005 budget estimates, SADI would cost just over $ 70.9 million.
38:(EWO) to evaluate and determine various classifications of threats to the aircraft, identifying various signals including search, acquisition, and tracking radars as well as communications. Because it allows a broad view of the RF spectrum, its situational awareness also provides for analysis of the efficacy of jamming techniques employed by the EWO using other systems. First manufactured in the late 1960s, the system is a passive
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First developed in the early 1960s, the ALR-20 began appearing on B-52D bombers (before 1967) and B-52Gs in 1967-1969. The ALR-20 did not undergo any significant upgrades or design changes until the 1980s. In the 80s, solid-state components were added to the system's tuners upgrading older tube-based
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The B-52D also received new upgrades to improve its combat effectiveness, most significantly with the "Rivet
Rambler" program, conducted from 1967 through 1969 to provide an improved ECM suite. Rivet Rambler, more officially referred to as the "Phase V ECM Fit", fitted the B-52Ds with the following
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Into the early 2000s, it was determined the system was "becoming unsupportable due to vanishing vendors and obsolete technology". Under the B-52 Situational
Awareness Defensive Improvement (SADI) program, the ALR-20 is expected to be replaced with a defensive system upgrade. The upgrade is expected
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During 1967-1969... This involved the fitting of... one AN/ALR-20 panoramic receiver set. The Phase VI ECM Defensive
Avionics Systems upgrade... was started in December of 1971, but it took several years of development and testing. The equipment added as part of Phase VI consisted of an AN/ALR-20A
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for the display (seen in the image to the right) had an orange tint displaying six different horizontal lines that represented a part of the spectrum. The signals displayed on those lines may be quickly analyzed allowing the EWO to bring the proper countermeasures for multiple different threats at
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A "Phase VI ECM Defensive
Avionics Systems" upgrade, codenamed "Rivet Ace", was begun more or less near the end of the EVS upgrade. It included a comprehensive update of countermeasures systems for the B-52G and B-52H, including: An AN/ALR-20A wideband countermeasures receiving set, with antennas
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Through the SADI program, Boeing will replace the aging ALR-20A Electronic
Countermeasures Receiver System and the ALR-46 Radar Warning Receiver on the B-52 Stratofortress. These upgrades are expected to offer up to a thirty-fold improvement in system
307:...replacing the AN/ALR-20 Panoramic Receiver System. The present AN/ALR-20 system, designed in the 1960's, is becoming unsupportable due to vanishing vendors and obsolete technology and has extremely limited SOJ support capability.
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B-52Ds were equipped with an extensive suite of electronic countermeasures during the 'Rivet
Rambler' programme of 1967 to 1969... This included the addition of... the AN/ALR-20 panoramic receiving set
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372:"40 Years ago the USAF retired the last B-52D, the BUFF model used to bomb North Vietnamese targets during Christmas Bombing Operation Linebacker II"
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The ALR-20's panoramic display is the EWO's primary source for analysis of potential threats through a very wide part of the
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littered all over the aircraft. The "20 Scope" is the primary tool for detecting and analyzing threats.
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549:"Iron Butterfly' – a close look at the B-52H Stratofortress during Exercise Diamond Storm 2019"
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Electronic
Warfare Officers undergo extensive training concerning the ALR-20 panoramic system.
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The Story Behind the Secret
History Part II. Getting B-52s through the Soviet Air Defense
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The AN/ALR-20 radar warning system that detects and prioritises multiple threats...
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Benefifits from
Funding the MSD Engineering List: A Fiscal Year 1999 Case Study
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Department of the Air Force Fiscal Year 2004/2005 Biennial Budget
Estimates
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Occupational Survey Report - Electronic Warfare Systems - AFSC 2A1X7
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Boeing Awarded Contract to Develop B-52 Defensive System Upgrade
46:. It is the primary tool used by the EWO to evaluate threats.
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Federation of American Scientists - Military Analysis Network
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AN/ALR20A Panoramic Display - Illustrated Parts Breakdown
198:"AN/ALR-20 (Panoramic Receiver Set, Phase V ECM Fit)"
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aircraft. As a stand-alone system, it is used by the
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USAF B-52 electronic countermeasures receiver system
148:List of military electronics of the United States
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330:gear: An AN/ALR-20 panoramic receiving set.
940:Military equipment introduced in the 1960s
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920:Military electronics of the United States
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173:"Repair of AN/ALR-20 Panoramic Indicator"
153:Joint Electronics Type Designation System
925:Equipment of the United States Air Force
580:AF.mil - B-52H Stratofortress Fact Sheet
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884:Category:Electronic countermeasures
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58:Until the late 1990s, the ALR-20's
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370:Leone, Dario (December 17, 2023),
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476:Air Force Institute of Technology
424:Guse, Paul (September 14, 2000),
26:providing a panoramic display of
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256:"3.0 The B-52 In The Modern Era"
112:Receiving Set Controller - LRU-1
524:Blank, Steve (March 29, 2009),
342:Baugher, Joe (April 21, 2021),
547:Mitchell, Sid (May 29, 2019),
321:"2.0 The B-52 In The Cold War"
44:tuned radio frequency receiver
30:(RF) spectrum on US Air Force
24:tuned radio frequency receiver
1:
319:Goebel, Greg (June 1, 2024),
297:, February 2003, p. 1178
254:Goebel, Greg (June 1, 2024),
229:Pike, John (April 22, 2000),
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124:Radio Frequency Tuner - LRU-9
121:Radio Frequency Tuner - LRU-8
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915:Electronic warfare equipment
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894:Category:Electronic warfare
345:Boeing B-52G Stratofortress
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40:Electronic Support Measures
36:Electronics Warfare Officer
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930:Electronic countermeasures
620:United States Armed Forces
461:Gehrich, David L. (2004),
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950:Radiofrequency receivers
553:Aviation Spotters Online
358:countermeasures receiver
96:electromagnetic spectrum
22:is an airborne wideband
945:Radar warning receivers
712:Missile Warning Systems
684:Radar Warning Receivers
400:"B-52H Stratorfortress"
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77:Technical description
826:EC-130H Compass Call
472:Wright-Patterson AFB
404:Air Force Technology
118:Power Supply - LRU-3
816:EA-37B Compass Call
406:, September 6, 2024
32:B-52 Stratofortress
935:Electronic warfare
616:Electronic Warfare
376:Aviation Geek Club
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60:panoramic receiver
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115:Panoramic Display
62:display utilized
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841:Lockheed U-2
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440:reliability.
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98:. The early
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68:
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55:technology.
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20:AN/ALR-20(A)
19:
18:
846:MQ-9 Reaper
231:"AN/ALR-20"
909:Categories
861:RQ-20 Puma
781:AN/ALQ-157
776:AN/ALQ-147
771:AN/ALQ-144
692:AN/ALQ-218
663:AN/ALQ-260
658:AN/ALQ-135
653:AN/ALQ-101
558:August 17,
381:August 17,
325:AirVectors
301:August 17,
265:August 17,
260:AirVectors
159:References
137:AN/ALR-20A
107:Components
766:AN/AAQ-24
748:AN/SLQ-49
743:AN/ALE-47
720:AN/AAR-47
702:AN/ALR-67
697:AN/ALR-20
673:AN/SLQ-32
668:AN/SLQ-25
648:AN/ALQ-99
643:AN/ALE-55
638:AN/ALE-50
631:(Jamming)
134:AN/ALR-20
794:aircraft
682:Passive
474:, Ohio:
240:July 21,
208:July 21,
202:CMANO-DB
183:July 21,
177:GovTribe
142:See also
129:Variants
82:Features
627:Active
618:of the
50:History
736:Sytems
103:once.
42:(ESM)
734:Chaff
730:Flare
501:(PDF)
468:(PDF)
295:(PDF)
732:and
560:2024
535:2024
509:2024
483:2024
435:2024
412:2024
383:2024
353:2024
303:2024
267:2024
242:2024
210:2024
185:2024
792:ESM
911::
562:,
551:,
516:^
470:,
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327:,
323:,
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279:^
269:,
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233:,
217:^
200:,
175:,
608:e
601:t
594:v
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