Fascinating stuff. I served in the Royal Air Force in the late sixties and early seventies. I wonder how many of your members know of the British operated AN/FPS6 height finders used in the UK air defence network during the 1960`s, and modified, for reasons I don`t know, with a Marconi transmitter, display system and tell back system. I also did a tour at 117 Signals Unit, on Mount Tai Mo Shan in Hong Kong, between 1972 and 1973, where we were equiped with an American AN/FPS 6 which I think was up to AN/FPS90 mod. state, and more unusually still an AN/FPS20 search head. I tried to follow the modification trail of this radar through the documentation, and, if I remember correctly, decided that it was a hybrid AN/FPS91A and AN/FPS100. We also had a USAF liaison NCO called Mike Tartaglia. If you read this Mike, I`d love to hear from you.

MSG (Ret), USA. In 1960`s was a 16H MOS. Member of 31st Artillery Bde (AD), Pittsburgh, PA, and 40th Artillery Bde (AD), Presidio of San Francisco, CA. Worked at both HQ primarily in Operations. Retired from INARNG in 2004 with MOS 13Z as 38th DivArty Intel Sgt and Acting Command Sergeant Major. Have been doing some research into the old ARADCOM. Your site here is useful to me for this. Thanks. CL

I remember at Keesler in tech school circa 1971, instructors said television would change. Maybe not as fast as they thought, but spectrum watchers note: “Depending on the outcome of discussions in Congress, television as we know it may end at exactly midnight Dec. 31, 2006. That’s the date Congress targeted, a decade ago, for the end of analog television broadcasting and a full cutover to a digital format. If enforced, that means that overnight, somewhere around 70 million television sets now connected to rabbit ears or roof-top antennas will suddenly and forever go blank, unless their owners purchase a special converter box. Back when the legislation was written, New Year’s Eve 2006 probably looked as safely distant as the dark side of the moon. But now that date is right around the corner and Congress and the FCC are struggling mightily to figure out what to do.” The rest of the story is at MSNBC: http://g.msn.com/0MNBUS00/2?http://www.msnbc.msn.com/id/7593620&&CM=EmailThis&CE=1

Yes, the maggie would emit a high pitched squeal when it was radiating. This squeal was a product of subharmonics of the resonance within the plate`s cavities. I remember a film at Keesler in 1972 about the FPS-6 height finder where the narrator said that the first thing that a good radar maintenance troop should notice when entering the height finder tower was whether the transmitter was running or not by the presence (or lack thereof) of the maggie`s characteristic squeal. Klystrons and twystrons would squeal somewhat too but they were so heavily encased in shields and water jackets that the sound was effectively muffled. However, you could usually tell when they were running by the buzzing produced by their trigger amplifiers. (Which brings up yet another memory of days gone by: How many of you remember adjusting the capsule voltage of the trigger amp`s giant hydrogen thyratron tube based on the bluish-purple color of the tube`s glow? Also, when the tubes were replaced, do you remember how we made table lamps out of the old tubes?) Do And yes, waveguide arcing was quite audible. Remember the tremendous amount of power the waveguide was carrying. When it arced (which usually destroyed the waveguide) you knew it!

Gary. I believe the `singing` was due to movement in the laminations in magnetron structure. The indidual layers would vibrate when excited. Yes, to hearing arcing in the waveguide. Frequently, the arcing was from reflections caused by misalignment of sections of waveguide, or foreign matter (remnants of quartz tubes - FPS-6) interfering with the energy path inside the waveguide. I have heard many tales of techs cooking chickens, etc., at the feedhorns of an antenna. Also, who would have thunk that magnetrons would become the core of an everyday home appliance (microwave oven). Sidebar - while at Murphy Dome (1964) our FPS-6 developed an internal leak in a flexible waveguide section, causing it to become `pregnant`. (C-section was not performed.) This was, I believe, published in one of the Air Force periodicals at the time.

Besides misaligned or loose waveguide joints, arcing was also caused by contamination (corrosion, metal filings, remnants of quartz tubes, etc) in the waveguide. Most all radar waveguides were dehumidified to keep moisture low to prevent corrosion and many of the high powered radars also had their waveguides pressurized with sulfur hexafluoride gas (a dielectric) to prevent arcing. And per Hank Brand`s sidebar, Amanda called their first microwave ovens `Radar Ranges` due to their kinship to radar magnetrons. Supposedly, the invention of the microwave oven was a result of 1950s-era radar engineers finding the candy bars in their shirt pockets melted after working around operating radars. (This also resulted in early USAF radar maintenance troops having to wear those little radiation detection badges like x-ray technicians do now. Improved RF shielding practices cured that little problem.) It wasn`t until the mid 1970s that small magnetrons could be economically produced and mocrowave ovens became affordable for common households. While I never personally cooked a chicken by hanging it in front of the feedhorn (although I, too, have heard of it being done) we used to hang a 4ft fluorescent tube on the sails of our mobile radars so we could monitor the system from the beer tent after duty hours. A glowing tube meant that the radar was still transmitting.

hutchinson afs ks,793rd 6-67 to 7-68 ,cross city afs 691st 8-68-10-69 hofn afs iceland 661st 10-69 was 27650 (i think)would love to hear from others who served at adc radar sites

Well, Gary. I know of three additional klystron-powered radars from `my day`. First, the AN/FPS-18 gap-filler. Second, AN/FPS-49 BMEWS tracker. Finally, AN/FPS-50 BMEWS detection radar. The main reason I can remember for using a klystron is transmitter frequency stability. The klystron was `pumped` by the receiver, making the receiver & transmitter perfectly in tune. MTI/doppler requires that the transmitter & receiver to be tuned accurately, and this assured that. A maggie on the other hand, wasn`t aligned to the receiver, but rather it kind of the other way around - you tried to get the receiver tuned to the maggie freq; sometimes not so succussfully (we never did get our FPS-14 to correctly tune, consequently, no MTI).

To amplify the remarks of Gene and Gary, the FPS-20 used a klystron, replacing the magnetron used on the FPS-3. One major reason was the stability, added to the reliability. It could be quite problematical to keep the receiver accurately tracking the transmitter frequency, which was governed by the shape of the cavities in the magnetron. I believe many of the IFF/SIF interrogators used very small klystrons.

The AN/FPS-7 and AN/FPS-107 family of search radars also used klystrons. Also using a klystron tube was the AN/FRT-49 (``Fart-49``) high-power linear amplifier for the AN/GKA-5 Time-Division Data Link (TDDL) transmitter. As the additional-duty Radiological Protection Officer (RPO) at two radar stations (Fort Fisher AFS, NC, and North Truro AFS, MA), I remember that the cabinets for those klystrons were lead-lined because of secondary x-rays caused by the high currents. I also remember that every site visit by the host-base health physicist found the radiation levels outside the klystron cabinets to be well under the level considered safe when the transmitters were on. Speaking of Fort Fisher AFS, the former AN/FPS-26A height-finder radar there was one of the ones converted into an AN/FSS-7 (``Fuzzy-7``) SLBM detection and tracking radar. Its klystron was replaced by a twystron, a hybrid between a klystron and a traveling-wave tube (TWT). The AN/FSS-7 scanned like a conventional search radar, but when it acquired a target (satellite or missile), it would stop on a dime (so to speak) and begin its tracking mode. The antenna assembly weighed several tons, so when it went from search mode to acqisition & tracking mode, you knew it -- the entire tower shook very noticeably! I feel very priviledged to have seen the Fuzzy-7 in operation. All were phased out by the early 1980s, replaced by ``PAVE PAWS`` solid-state phased-arry radars.

I recall (as an ex-AFCS troop) that our tropospheric scatter systems operated with a klystron. With the transmitter on 100% of the time, the xmit/recv frequencies were not the same. I don`t remember all the details, but due to parts shortage, one time a significant communications trunk remained on the air for several days just fine without an operational power amp (PA). They bypassed the PA and used the exciter (which I think was only about 10W). The normal PA output was 10KW with an ERP somewhere in the megawatts off the billboard. This must have been in the summer, because in the winter we had enough trouble keeping that trunk in business with the PA on line. I think klystron tuning involved changing the cavity dimension slightly through the use of something that looked very much like a bicycle chain. Was there an equivalent in radar?

Power Amp 101: The Magnetron was (by modern standards) a crude, essentially non-tunable high power diode tube. The physical size of the plate`s resonate cavities determined the output frequency (although some maggies could be tuned with movable slugs inserted in the cavities but this was an awkward arrangement at best.) The maggie`s main drawbacks were poor frequency and power stability because both were dependent on the strength of the external magnets and the stability of the anode current. Since early (analog) MTI demanded a rock-solid output frequency, the poor maggie was a poor choice for precision systems. The reflex klystron, a triode tube, solved both problems (freq and pwr instablilty) and became the PA of choice for radar designers for many years. Unfortunately, the klystron`s price tag was many times that of the simple maggie. Also, the klystron`s output frequency was fixed, although just like the maggie, could be manually tuned a bit. The twystron, a marriage of the travelling wave tube (TWT) and klystron, came along and solved everyone`s problems. The TWT front end enabled the klystron to electrically change frequencies as fast as once each PRT and the klystron lower end produced rock solid power. Great MTI AND frequency agility (anti-jam.)

Okay, interesting observations all. If memory serves, the magnetron made a sound when it was radiating. This was called `singing,` I think. What caused that sound? (I don`t know, been a long time.) Bonus: Some technicians claimed to be able to hear arcing in a waveguide. Reasonable or was that along the lines of X-ray vision?

Reading about various a/c reminded me of F-106 interceptors taking of from McCord AFB right next to the VOQ (The Monsoon Inn). Two launching at once caused the whole building to shake, rattle, and roll, and the noise was tremendous. We also had a flight of 4 F-106 a/c overfly Mt Hebo AFS (689th Radar Squadron) on Armed Forces day 1966. Their first pass was several thousand feet above the site and everyone just stood and looked up at them as they passed by. However, there was a second pass at well under a thousand feet above us, and when they went by almost everyone, including our drill team that was marching down the main street of the site, hit the deck! Now that got your attention and left everyone with a lasting impression of both the power and grace of the F-106. I have this F-106 fly-by on super 8mm film and will try to get it digitized for inclusion in radomes. Can`t say that I have this on film, but an F-89 did a bubble check at Mt Hebo in 1965 and flew between the FPS-24 tower and the FPS-90 tower. Exciting view into the cockpit of the F-89 from the FPS-24 catwalk (85 feet above the ground), but no lasting effects. When a 3 ship cell of B-52 a/c overflew Mt Hebo in 1966, they came in low from the Pacific Ocean and then pulled up over the site (our radar towers were about 3400 feet above sea level) by less than a thousand feet and shook the site buildings so much that the FPS-90 receiver went off the air. We knew these B-52 a/c were headed our way and many of us were outside to watch as these planes showed and sounded their stuff in a most impressive manner. To bad I didn`t have a camera handy.

Responding to Gary Jacobs and the FPS-26A shaking the tower when the antenna slewed to track a target..... Unlike the FPS-6 and most other antennas that were driven by electric motors, the 26 was slewed in azimuth by an hydraulic motor which was able to do it very quickly and with much more torque. I suppose the idea was to be able to lock on to the target as quickly as possible. I can`t recall if the antenna nodded by hydraulics or not. One thing I do remember is that the hydraulics leaked a lot. At Saratoga AFS, we were constantly up on the antenna adding fluid and cleaning up the leaks with rags. On another note, growing up in Watertown, NY in the late 50`s I experienced lots of low level flyovers by B-47s and B-52s. In addition to the 655th Radar Squadron, a separate Air Force radar bomb scoring squadron was stationed just outside Watertown, near the municipal airport. As a result, the air was always full of SAC`s finest.

Let’s get technical. The FPS-26A used a klystron. How common was the klystron versus the magnetron in the air defense radars? Extra credit: Why was one used more than the other, if in fact that was true?

The F-104 Starfighter could get airborne and on target very quickly, but had a limited range. I always loved the thunder,noise and smoke from the F-4 Phantoms. I saw the Thunderbirds do a show at Eilson AFB Ak. in the summer of 1969 and were flying the Phamtom, and the next day they came up close to Murphy Dome and practiced so we were able to watch them again.

For Gary Jacobs, you are correct: The Bronco was the OV-10. The designation ``OV`` *probably* indicated ``Observation Vehicle`` (as it was a reconnaissance aircraft), but I am merely speculating here. By the way, there are quite a few websites about the OV-10. -- Tom

Until you`ve seen (read that heard) an F-4 go through mach 1 VERTICAL, you haven`t lived. Bubble check, Kume Jima Okinawa, 555th in late 1964.

Two air defense era aircraft I wish I could have seen in flight: the B-58 Hustler and the B-36 Peacemaker. The former because I would like to hear the sonic boom. (Remember those television commercials that explained them?) The B-36 just for the sheer size and sight. I liked the old Jimmy Stewart “Strategic Air Coomand” movie that showed them. A quote from an “Air & Space Museum” article, “B-36 at the Crossroads, “…Simulated B-36 attacks on bases in Florida and California were met by three front-line fighters: a North American F-86A Sabre, a Lockheed F-80C Shooting Star, and a Republic F-84 Thunderjet. Radar picked up the intruder 30 minutes out; the fighters took 26 minutes to climb to 40,000 feet and another two minutes to find the B-36. The fighters were faster than the big bomber, but their wing loading (the ratio of aircraft weight to area of the wings) was so high that they couldn`t turn with the bomber without stalling in the thin air. Even if a B-36 were detected and Soviet fighters caught it, the pilot could evade them by making S-turns, said the Air Force.” B-36 doing “S” turns. Sweet. (Thanks for the OV-10 info; wonder why it was apparently unsuccessful. Didn’t seem to stay in the inventory very long?)

I was stationed at the 785th AC&W Squadron in Finley, North Dakota from Feb 1954 until June 1955.

Of the planes of the air defense era, I always thought the F-100 was the most beautiful. Simple, clean lines. It looked like it was flying sitting still. But for the Hammer of Thor, the roar of the F-4 was second to none in my book. Plus that bat-wing look from a distance was menacing. Even the name was cool: Phantom. You had a real bad day when the Phantoms showed up looking for you. My favorite Thunderbird shows were F-4s. At Keesler in 1971 or ’72 I saw a show that was one of the most extraordinary aerial demonstrations of my lifetime. I swear the ground shook when they went by. After they were declassified, I saw flight demonstrations of the U-2 and SR-71. I wondered if years ago when the FPS-26A was looking for interesting targets that was what it found. We’d have occasional targets around Selfridge ANGB, Mich. (near Detroit) that moved at remarkable speeds. Maybe it was them. Maybe other 26 tower techs can recall how, when the antenna changed azimuth (that is, compass direction, I am not sure I have the correct word), the tower itself mildly swayed with the torque. For those around the FPS-35, I still remember the “swoosh” of the sail (the antenna) rotating in the wind. Once at Selfridge I watched a Coast Guard helicopter fly right over the from nearby Lake St. Claire (sp?) and I wondered if its instrumentation went screwy from what I recall was a five megawatt output. (Again here I am not sure my memory is accurate on that; I didn’t work in that tower.) One last aviation curiosity: I think they were OV-10 “Broncos,” twin engine aircraft used in the Vietnam era as small cargo/transport planes. They used to fly around and then shut their engines off. That was to glide around since in Vietnam their engine noise gave them away. Now that I think of it, I have no idea what “OV” would stand for, so I may be wrong. I think the Bronco is right, though.

Was at 604th acwron Freising Germany 1954 to 1956. Landshut,Germany 1956 to 1958. Anyone out there at this time.

I was a 303X2 from 1956 to 1976, now retired in Fort Myers Florida.

I was stationed at Moriarty AFS for a short period of time in the late 1950`s before volunteering for a transfer to Pagwa AFS, on the Pine Tree Line, w/the hope of a consecutive tour to Japan. When that didn`t pan out, I opted for Otisx AFB, on Cape Cod, and finished my tour there.

Would like contacts from the 813th AC&W . I was there in 1962- I worked in Radar Maintenance.

Great site, I`m still going through the guestbook looking for names I recognize. I was at King Salmon AK Mar 80` to Apr 81 and then Galena AK from Sep 85 Sep 86. Some of the best times of my 20+ AF years, learned a lot from the local people and just enjoyed it. Les

send me more information on this i was on uss watchman agr 16 10 july 63 until decommission

I am searching for a patch from the Air Force 717th Aircraft Control Warning Squadron in Alaska. I believe the timeframe is 1946-1952. Please contact me with any information. Thanks.

I served at 665th Radar Squadron in Calumet Michigan for 3 years (1974-1977). Had an awesome time in the western UP, and travel there when time permits to this day. Recently skiid at Mt. Bohemia - - - - - what a rush. Worked at GATR. Lots of good friends. Played softball on the travelling team. Played Ice hockey as well.

I was stationed at Condon AFS in 1951 (approximately) before transferring to Thule AFB, Greenland. In Thule I was in the 6612th Air Police Squadron. After a career with the US Forest Service I retired in central Oregon, only 100 miles from Condon and plan to revisit the area soon. Les

Just in case anybody is interested, my status on the site rosters where I was stationed, now has my e-mail address. I am no longer Status Unknown.

I was stationed at Winnemucca, Nevada at the same time Donald R. Cash was. I was there Feb 1964 thru Jan 1967 then transferred to Indian Mountain,Alaska 1968-1969, then back to Keesler. I retrained to FSQ-7 SAGE Computer Repair and off to Syracuse NY then back to Keesler AFB as an instructor in the AC&W Radar Course. Anybody out there with good or bad memories (HA HA) of me, give me a email at capnront@hotmail.com. `The capnront refers to my stint as a Dive boat captain in the Florida Keys until my Heart attacks in 2000, still hanging in there, Now live in Kentucky.

would like to hear from those who served at the 664th and Detroit ADS.Also i lost Chief John Malarsies mailing address. Any help ?? thanks bill

I was a member of the 691st Radar Sqdn, Cross City, FL from 1960 to 1963

Stationed at 908th 1963-1968

I wish more information by ASOC.

Perhaps for those looking for a good general history of radar, with a chapter on SAGE, I recommend “The Invention that Changed the World,” by Robert Buderi, copyright 1996, Simon & Schuster, ISBN: 0-684-81021-2. Bear in mind it is mostly concerned with World War II, though that’s a heck of a good story. The books also has the gee-whiz details of what comprised the FSQ-7 digital computers, though not in a part-for-part comparison to the modern personal computer. Also check out the column to the left of at the Radomes web site, repository of much technical information. I think it was physicist I.I. Rabi who said that WWII could have been won without the atomic bomb, but it could not have been won without radar. Perhaps historians of the future may write the SAGE system that was concerning the Cold War.

Re: The Invention that Changed the World - right you are, Gary. It`s one of the books on the Radomes Recommended Reading list. Take a look at http://www.radomes.org/museum/readinglist.html.

I was stationed at tin city in 1964-1965 I was an Electrician

I used to work, in 1968, as a sergeant at SMCU at 22NORAD in North Bay. Now that I am an old retired guy with my own computer, I am looking for information. This is a curiosity thing and I doubt if it would involve any classified material but I was wondering,based on 1968 technology, what would the power of the 22nd computer be,compared to my desktop. I have 96megs RAM and a 13Gig hard drive. Would appreciate this information or links where I could persue the mattter. Thanks

I was stationed at the 752nd Radar Squadron at Empire Mi. from June 1966 until January 1969. I had a great time there. We would all go to the Brook Bar in Traverse City on the weekend.

I was stationed at Cape Lisburne as a radar operator from Nov 1958 til Nov 1959.

I served at the following Locations/Units during my Military Career (1946-1973):(My email address is: Hanshin (Osaka,Japan) 618th AC&W Sqdn.-1947/49. Roslyn Heights, New York 503rd AC&W Group-1949/50. Galena, Alaska Det 2 632nd AC&W Sqdn-1950/51. Kirtland AFB, New Mexico 690th/135th AC &W Sqdn-1951/52. Tierra Amarilla, New Mexico 767th AC&W Sqdn 1953. Rabat-Sale French Morocco 316th Air Division(Defense)- 1953/55. Kirtland AFB, New Mexico 34th Air Division 1955/57 . West Mesa Air Force Station, New Mexico 687th AC&W Sqdn 1957/58. Rabat-Sale, Morocco 316th Air Division (Defense)1958/1960. Marietta, Georgia 908th AC&W Sqdn 1960/61. Saglek Bay, Labrador 924th AC&W Sqdn 1961/62. Hamilton AFB, California 28th Air Division 1962/66. Kindsbach, Germany Det 1 615th AC&W Sqdn 1866/70. Fortuna, North Dakota 780th AC&W Sqdn 1970/71. Hofnfirdi, Iceland 667th AC&W Sqdn 4 months in 1971. Thule, Greenland 12th Missile Wing 1972. malmstrom AFB, Montana 24th Air Division 1972/73. `Declined` an assignment to Alice Springs, Austrailia. Terminated Military duty 3 Feb 1973.

For those of you who might be interested in seeing what the new ballistic missile defense Sea-Based X-Band Radar (SBR) and its giant floating platform look like, go to http://prn.newscom.com/cgi-bin/pub/s?f=PRN/prnpub&p1=20050405/NETU029&xtag=PRN-prnphotos-44820&redir=preview&tr=1&row=1/.

I spent 3 years as an operator at the 731st at Sundance, and a while at the 752 at Empire Mi. Met some real interesting people, had some real interesting adventures.

Keesler AFB 1966-67 SAGE. B.U.I.C II Cape Charles, VA 1967-68. B.U.I.C. II 621TCS, Udorn, Thailand 1968-69. B.U.I.C. II, Baudette AFS 1969-1970. Retired after 4 years as a SSGT.

752 Radar Sq Empire 1958 - 1961 753 Radar Sq Port Austin 1972 - 1974

If you were stationed at the 794th AC&W Cape Newenham Check out www.msnusers.com/capenewenham 160 members and over 1100 pictures of the Cape

Hi, I was stationed at Gibbsboro AFS, 772nd Radar Sq., from June 1968 to Oct 1969. Gibbsboro was a great place to be stationed for a first assignment. Only problem was that the single guys had to live in the barracks at McGuire AFB and endure a nearly one hour drive to the station. Some of they guys went together and shared an apartment near the station - but they made you maintain a bunk in the barrack. And of course since you were `assigned` to the barracks, you occasionally had to perform morning clean up. I`ll try to write more about Gibbsboro later. Cheers Brian USAF MSgt Retired

I was stationed at the 785TH AC&W Squadron, Finley North Dakota from May of 1954 to August 1955. I was wondering if anyone out there was at the Site about the same time. I played Basketball and Softball for the base and married a local girl in June of `55. I was ALSO stationed at the 624TH AC&W Squadron, Naha Okinawa from September `55 to March of `56 and finished my enlistment at the 1st Operations Squadron, Selfridge AFB, Michigan. We are also trying to plan a reunion at the 785th sometime this summer and would like to hear from anyone interested in attending. The reunion would of course be for anyone who served at the Base. Hope to hear from you just to shoot the bull or your thoughts about the reunion.