by Steve Bragg KA9MVA	DARTS | HamHUD | KA9MVA Home

One of the most successful projects of the MIT Radiation Laboratory in microwave radar was the SCR-584 radar, an anti-aircraft gun laying system. This feat was accomplished under the guidance of Ivan Getting and Louis Ridenour, although many very brillant individuals were also involved.

This page is a memorial to their genius, a virtual obelisk raised in their honor.  Though my career in radar and microwave radio began 42 years after the SCR-584 became operational, I feel a certain connection to their genius.  In my studies of the Radiation Laboratory journals, I am humbled by the accomplishments of this team.  The SCR-584 and its technology are a monument to the Gemini-twin philiosophies of Ockham's Razor and KISS.   In an age when it was an accomplishment to get a thousand vacuum tubes to function for more than a few hours, the Rad-Labbers, by dint of God-given talent, hard work, and the genius of simplicity, wrought a beautifully-simple and deadly-accurate radar which won a war, and inspired a generation of radar designers.

I also hope to honor the brave GI's who operated the SCR-584 in World War II, and those who used the '584 in the "Golden Age" of aircraft and missiles, beating a WW-II sword into a Cold-War plowshare. Tell your SCR-584 stories, one and all, so that the world may learn what was done for the protection and prosperity of the United States of America, and free peoples around the world.

• 3-29-2006 Added Ed Bean's RAWIN story.
• 7-1-2004 Julius Hawk sent me some nice pictures of a restorable SCR-584 he's seen.  I put them up in the "SCR-584 On The Web" section, below.
• 10-28-03 Removed references to MITRE in context of the MIT RadLab.  I was kindly corrected by Dr. Lee at Stanford that while MITRE personnel did come from the RadLab, there is no direct organizational connection.
• 10-10-03 Added links to more "War Electronics Report" articles from 1946 (thanks Fred!)
• 11-19-02 Added Greg Goebel's website.
• 8-26-02 Added 2nd installment of the Electronics Magazine 1945-1946 series on the SCR-584.

The SCR-584 team was under extreme time pressure to get the radar going, yet they succeeded brilliantly.  They used what now would be called "rapid prototyping", utilizing as much off-the-shelf stuff as possible, often in very creative ways.  I love this quote, from the Lee Davenport IEEE interview:

" We had no compunction whatsoever about bending the rules a little bit if necessary to get something done. We would buy a washing machine if it would bring a quicker result....we were expected to hurry and we were not to be put aside for anything. That permeated the building of XT-1 [the SCR-584 prototype]. The first experimental truck was a project that we moved heaven and earth to get done quickly. We had no reluctance whatsoever about going to an outfit that could spin a 6-foot aluminum parabola..."

• Henry B. Abajian: XT-1 power, SCR-584 European support (interview)
• Britton Chance: XT-1 and SCR-584 ranging circuits, other circuit design (interview)
• Lee L. Davenport: development and field testing of the XT-1, SCR-584 field support (interview)
• Ivan Getting, project manager, magnetron modulator, Roof System and XT-1 (interview)
• George Harris
• Nathaniel B. Nichols: control systems (obituary)
• Dr. Ernest C. Pollard: Moving Target Indicator (display) (interview)
• Louis Ridenour, project manager
• Leo Sullivan, electrical engineer (interview)
• Dr. Fred B. Wood, Sr.: design of key microwave components.  (bio)

• Radiation Lab Series: This journal includes the Fabulous 584 and the microwave technology behind it.  Available on CD at www.artechhouse.com for $295.  The entire series is on 2 CDs.

• RAD LAB JOURNALS: Vol. 1 pps 207-210, 228, 284-286.
• SPECIFICATIONS
• SCR-584 Repair Manual  (Yes, I finally have one!):

	Back side of pedestal and dish (783K JPG), showing elevation pot (with OIL plug!) and selsyn, elevation drive motor and gear housing, and slip ring compartment.
	Instead of digital or even an analog computer, the SCR-584 used a MECHANICAL computer in its PPI unit.  State of the art in 1944!
	Look at the slip ring connections between the pedestal and the rotating antenna.  Here is an entire engineering project all by itself.
	Check out the oil can used to lube (!) the potentiometers.  When was the last timeYOU had to lubricate a "pot"?

• FULL DISCLOSURE:   In November-December 1945, and February 1946, Electronics Magazine ran a "War Electronics Report" special that included, you guessed it, our favorite ol' radar.  Below are pages from the article I scanned.  I'm pretty sure the copyright on these has expired.  I apologize for the misaligned copies;  I hastily copied these years ago when I was in college.  Amazing that I still have them.

 

Part I (Nov 1945)
Part II (Dec 1945)							(Only  6  pages)
Part III (Feb 1946)	Coming	Soon!

Here's more from the "War Electronics Report" (Thanks to Fred Carl, Director, Infoage Science-History Center at Camp Evans)
Radar CountermeasuresSCR-268 & SCR-270 Radars

• STOPPING THE BUZZ BOMBS:  The SCR-584 virtually STOPPED the V1 "Buzz Bomb" bombardment of England, with a better than 90% kill ratio (100 out of 104, according to Leo Sullivan).
• ARTILLERY CHAMP:  The 115th AAA Gun Battalion was the first to be outfitted with the then-new (and TOP-SECRET!) SCR-584.  Here are some pix of the "D" Battery of the 518th AAA Gun Bn. with their 584, and a newer radar.
• EXTRA! EXTRA!  A "swell" lithograph of the SCR-584 from Life magazine, June 1943.
• IN THE UK: Great pix of the 225th AAA Searchlight Battalion's use of the SCR-584 during the Winter of 1944 in the UK.
• D-DAY: The venerable 584 was adapted to assist in tactical air strikes.
• BATTLE OF THE BULGE:  The SCR-584 helped ensure air superiority.
• BACK HOME: Apparently, the Navy got  worried about Axis strikes on their Brooklyn shipyard, so SCR-584's and guns were installed at Fort Tilden.
• AN ORDERLY ACCOUNT:  Greg Goebel emailed me about the online history of radar in WWII that he's putting together.  Hope you enjoy it!

• AN/MPQ-12-AN/MPM-38  (Corporal Missile System)  This US Army field artillery missile system used a slightly modified version of the '584 to track the missile in AZ, EL, and range. This information was furnished to an analog computer system. A separate CW Doppler radar determined velocity and this was also provided to the computer.  The most notable modification to the SCR-584 was the removal of the antenna from the van (as in the SCR-784). The '584 has a lift assembly that can raise the dish up through the roof or  lower it when moving the van to a new location. In the Corporal system, the antenna mount was moved to a separate towed trailer. The modified radar designation was AN/MPQ-12 . There were a few other electronic modifications as well.  (Thanks Neil A.!)

 
• M-m-m-my CORONA:  The SCR-584 was modified to control and beacon-track (using an onboard transponder) the CORONA spy satellite, which was the first successful photoreconnisance satellite (covered in American Heritage of Invention & Technology magazine).  (No "skin" returns were involved--the range was too far for the unaugmented '584.)  The '584's PRI (Pulse Repitition Interval) was changed to give an unambiguous slant range of around 1500 miles. The modified radars were deployed at Thule, Greenland (along with BMEWS; brrr!); also in New Hampshire, Alaska, Hawaii, and the Indian Ocean. They operated successfully during the 1960s before more modern trackers became available. (Thanks Tom F.)

• THE SPACE AGE:  Mod II is an SCR-584 with massive upgrades in both the antenna and the electronics.  Wow, what a sweet antenna!
• WEATHER SEEKER:  The National Severe Storms Lab in Norman, Oklahoma has a weather radar, used for teaching, which incorporates a 584 pedestal.  NOAA also used an unmodified SCR-584 for a long time as an auxillary weather radar.
• MORE WEATHER RADAR STUFF:  Reader Ed Bean contributes the following:
  My fond memories of the SCR-584:

     In 1946 post-WWII research activities, MIT established a Weather Radar Research Lab under the direction of Alan Bemis. As part of the project, an SCR-584 was obtained and located on a hilltop close to Bedford (Hanscom) AFB. The '584 was used without modification to measure wind speed and direction at all altitudes, by tracking a balloon-borne corner reflector kite… This data was used to correlate the various types of weather phenomena with radar characteristics and displayed information, providing the basis for the modern day weather radar systems.

     … I personally had the privilege of running the '584 "RAWIN" [Radio WINds] station, sending up balloons in all kinds of inclement weather. The simplicity and reliability of operation of the '584 was attested to by the fact that the only training I received was a day or two of verbal instructions by an MIT scientist.

     There were very few maintenance problems. The "J" scopes and the "PPI" scope were calibrated in mils rather than degrees, owing to its fire-control heritage. The tracking capability was semi- automatic. The operator had to keep the displayed signal within the limits of a range gate. This was accomplished with the aid of a motorized potentiometer which helped to keep the range gate lined up with the signal… the antenna would stay locked on to the target signal.

     During the 2 year time that I was the [RAWIN] operator, another MIT project, focused on infrared research, attached IR sensors to the the [SCR-584] parabola to test developmental heat seeking devices related to aircraft infrared signatures.

• MISSILES: In development, the first generation of semi-active radar-seeking missiles used the SCR-584 for illumination.  China Lake apparently still uses their '584 in missile research (I used to have a link, but it is now dead).  Wallops Island used SCR-584's in tracking research rockets.
• '584 HAS THE RIGHT STUFF!   In the opening scenes of the movie, "The Right Stuff", as two test pilots challenge the "demon" of Mach 1 (one of them then-Capt. Chuck Yeager) at Edwards AFB, an SCR-584 can be seen scanning the skies, tracking the planes.  Well, it's not really tracking, because the '584 is clearly in its helical-scan search mode. Anyone know where they got the '584 to make the movie with?
• AMATEUR RADIO:  a ham operator sets up a moonbounce station based on, you guessed it, our favorite little radar.

• STILL KICKING:  Radio-Research Instrument Co, Inc. of Waterbury, CT. still stocks parts, manuals, and complete SCR-584's.  Drexel International still repairs SCR-584s.
• JAMMING:  A somewhat-funny story of what happened to the SCR-584 (and Ivan Getting's backside!) when the radar was first successfully jammed (on purpose).
• NOVA: Nova documentary, “Echoes of War” in 1988 featured the SCR-584 at the Baltimore Radar Museum.
• BRITTANICA: article which talks about the venerable 584.
• OLD BUT RESTORABLE: Julius Hawk, whose father worked on SCR-584's at Monmouth, NJ, sent me some pictures of an SCR-584 that he thinks is restorable, perhaps even operable.  Please keep us apprised of progress, Mr. Hawk.

 

Roof mounted antenna in the raised position.	Power supply or modulator cabinet, I'm not sure which.	Full view of the trailer.	A closeup of the dish. Oh sweet conical scan!	Main operating console. Notice all the dust on the PPI panel, below.
Rectifier cabinet?		Mmmm, tuuuubes!		Thanks, Mr. Hawk!