A new thing to worry about

That RADAR killed birds in flight and had multiple locked gates on the stairs to the antenna platform where you had to remove the key to open each gate.

TWT on VHF? VHF is 30 to 300 MHz and TWT are typically built for 300 MHz up which would put it in the 300 to 3000 MHz UHF range.

That 8 MW was a combination of antenna gain, and the fact that the transmitter operated in pulse mode.

The prohibited communications on VHF was probably for security reasons. There shouldn't be much RF on the sidelobes or rear of that antenna. BTW, Microdyne built a lot of Telemetry recievers for deep space work. In '88 they would have been building their 1100 series of modular telemetry equipment. I think the 1200 series was introduced sometime around that time, followed by the 1400, the 2800 (limited production) then the 700 & 1620 as some of the last analog models. The first DSP based models were the DR2000 & RCB 2000

NASA was still using a 30 year old Microdyne reciever to track probe satellites in 2001. It had never been turned off, or serviced.

Have you seen the big dishes used by NOAA for their LEO wearther satellites? I worked on the turnkey upgrade for their Wallops Island installation that was built by Microdyne. It replaced a 20 year old Harris microowave system and had to control their 100 foot dishes.

We also built the pair of tracking stations for the European Space Agency. One fixed site, and the other mobile.

--
Offworld checks no longer accepted!

My bad, that ALTAIR installation is a wide band radar with what I assume are multiple feeds. I really wish I knew more about it and had been able to get in and see the operation. It's been 20 years and I remember the fellow I spoke with telling me of the enormous power of the darn thing. I do specifically remember being told that it used VHF frequencies in some modes. There is a story of it being aimed at a Russian trawler that hung around the islands. The tale speaks of the power being ramped up until smoke came out of the boat which made a quick exit from the area.

TDD

You obviously have had more experience with neater and higher power stuff than I've had. Is it OK if I envy you? *snicker*

TDD

That would be hard to do at HF or VHF since you can't focus the RF into a tight beam at those frequencies, compared to a couple degrees or less at microwave frequencies. :)

If you must, but I just like to trade war stories about equipment that would make newbie techs retch or fill their drawers when they see the size and the hazards involved. The sheer look of terror on their faces is priceless! Like me standing on the HV power supply inside a VHF high band TV transmitter so I can adjust the interstage coupling while the station is on the air. The end of the cabinet was removed, since it didn't have any interlocks, and i was standing on one of the transformers. It was either do it that way, or spend days removing the rear door, making a small adjustment, replacing the rear door then firing it up to find it still had too much ripple in the video bandwidth, shutting it down and starting over. :)

--
Offworld checks no longer accepted!

I've worked with a lot of high voltage power but there on the island the highest power runs were 4160 3 phase. The superintendent I was working with borrowed a wooden hot stick from the power plant crew. Lucky thing he was wearing the high voltage glove set. I think his hard hat popped off when his hair stood on end while we were plugging in the transformers. Did you know that a slightly damp hot stick will conduct electricity? Ya know shortcuts can be dangerous. This particular guy got himself killed a few years later when he fell down a shaft in Cairo while trying to change a lamp in a fixture on a big sewer project. He decided he didn't need that pesky safety harness.

As far as that big radar goes, I know I wasn't hearing things. It will operate in CW mode at VHF and UHF frequencies. Here's a link and I still wish I had gotten a closer look at that thing.

TDD

RADAR works by timing the reflections. They are using 'CW' to imply that there is no complex modulation.

Have you ever read the 'RADAR Handbook' by Merrill I. Skolnik? It's big, over 1500 pages & boring, but covers the history & technology of RADAR. :)

Here is an early edition:

Here is a copy of the new, third edition.

--
Offworld checks no longer accepted!

Oh come on, I know how RADAR works, I even own my own low power X-band Doppler unit. It's a blast to play with. I won't even pretend to know how that huge SOB ALTAIR works. The site mentions in the specifications "Modulation: CW and Linear FM Chirp" What do you make of that? Two different modes or a combination? Darn it, I wish I had asked more about it but a lot of the information was classified so I don't know how much I could have learned. There were guys wandering around out there who could make you feel like am amoeba because they were so much smarter. They all seemed to come from those alphabet universities. *snicker*

TDD

'FM Chirp' is a side effect of pulse modulation of some transmitter tubes.

Those 1500+ pages go into a lot of details that you might find interesting. :)

My MOS was broadcast engineer, but I did spend some time repairing Korean War era RADAR systems at Ft. Rucker. I really pissed of the RADAR tech I was assigned to work with. he would spend a half hour hauling everything from the truck to the RADAR site while I went in with a Simpson 260 and the manual. I would diagnose the problems before he was finished hauling everything the quarter mile walk between were we were allowed to park, and the base of the antennas. He got even madder when I told him the only training that I had was studying the W.W.II aircraft RADAR manuals in my high school's physics lab. The final blow was when I told him that RADAR was a stripped down TV set with no sound. :)

I bet those guys would have been lost looking at the 40+ 'D' sized schematics for the DSP based Microdyne RCB2000 dual telemetry receiver & digital combiner if they were still alive in 2000. Rf was down converted to a 70 MHz IF center frequency, and sampled from 50 to 90 MHz. Then the data was processed through FIR filters. A standard 70 MHz analog IF was created after the IF filter to allow the data to be recorded on standard instrumentation recorders. 70 MHz IF is a holdover from RADAR and early sat IF systems. It was also used in land based telcom microwave relays.

--
Offworld checks no longer accepted!

Some of those guys needed help tying their shoes but they could see patterns in the raw data and dream in differential calculus. When you were at Ft. Rucker, did you party in Enterprise? I tried to join up twice, back when I was a damn hippie freak in college there was this pesky draft thing going on and my contemporaries were shooting toes off, claiming to be gay or running off to Canada to stay out of Viet Nam. I wanted in The Air Force because they had the neatest toys to play with but unfortunately I wound up 4F. Darn it, I was trying to get in and all these goof balls were being dragged away screaming and kicking. 10 years later I tried The Navy, I was sent to Maxwell AFB where doctors told me to bend over so they could look up my butt and they determined I was in perfect health but too nearsighted. I didn't get to play with all the neat toys in the military. No big RADAR, no doomsday computers, no real live missile command, no ICBMs. Darn it, I feel left out, I wanted to blow stuff up by remote control.

This RCB2000 you're fond of, was it used to basically pick data out of all of the RF (noise) coming from any transmissions by a missile, satellite, aircraft or UFO? From looking at the information online about it, I gather that you could use it to pick out two precise slices of the spectrum to snag what you are interested in. Please, oh master, instruct me. 8-)

TDD

I wish you still had pictures, too - I used to do a lot of exploration / photography in old military places like that, but it's rare to find one where it hasn't been stripped of equipment. Sounds like an interesting place...

cheers

Jules

[christmas presents]

I registered for the draft at 18, and was given five separate 4F medical ratings. Two years later I was drafted for my electronics skills. Then I tested out of their three year course in broadcast engineering while I was in basic training. I was told that no one else at Ft Knox had ever passed that test without spending three years at Ft. Monmoth. The average score was 22/110 and passing was 42/110. They wanted me to fail and claimed the only copy they could find was missing two pages, which happened to be 22 questions. I got 82/88,

The Air Force is a stickler on good vision. My vision was about

20/200 & 20/400 when I was drafted. I can't legally drive without glasses, and I needed a stereo microscope to do surface mount work at the end.

The infamous 'Inter City Beer Missile'? A local brewery ran commercials in Cincinnati about their attempts to deliver their beer faster, and one 'failed' idea was to use Inter City Beer Missiles. ;-)

Some of the newer weapons systems are remote controlled by Telemetry. The smart bombs, with TV cameras are flown by remote control. Sometimes the operator is half way around the world. Others are controlled from planes or ground based personnel at a safe distance from the fighting so the control hardware isn't captured.

I should be fond of the RCB2000. It was the last new product I helped move from prototypes into production. It is a VME based system with two digital receivers, the control computer, the digital combiner and a spectrum display. Both receivers are tuned to the exact same frequency, but fed from different antennas to reduce fading and dropout on very weak signals.

I had to work with manufacturing engineering to improve our reflow solder process, write a lot of test procedures, and build test fixtures. I wrote a thick pile of Engineering Change Orders, and push them through before it hit the production floor. The documentation for that radio was about 1500 pages, with a lot of them 'D' size. (22.0 by 34.0 inches)

Diversity receivers were used on HF during W.W.II where two or three identical radios were used with separate wire antennas. The recovered audio was mixed together so the strongest signal was heard at all times.

--
Offworld checks no longer accepted!

I registered at 18 also and I didn't find out until 30 years later why I was turned away from the military during the Viet Nam war. I was talking with a friend who had been one of the top recruiters for the army and according to him, the secret to staying out of Nam was "allergies". I had stumbled upon the greatest secret of my generation and didn't know it. It wasn't my extreme myopia, it was my damn runny nose!

Speaking of tests, I was 15 or 16 when me and my classmates were all given this big military aptitude test ASVAB, I think it was and I scored 98% which I thought was pretty cool because I was the only kid in the whole school who knew what every tool shown on the test was and used for. There was actually a "saw set tool" shown on the test. Why a military test would have a carpentry tool on it struck me as a little bit bizarre but I was a teenager and I knew everything. *snicker*

The recruit processing center I went to was in Nashville and I rode a bus up there with several other young recruits and I will never in my life forget this one guy who was the stereotypical Hillbilly farm boy who had us all in stitches because he was so funny. I swear, he looked like Howdy Doody and Opie morphed into one. When the office personnel gave us all urine test cups, Opie exclaimed "I cain't piss, I dun pissed!" The recruiter told him to drink some water but Opie kept going on about not being able to go, so we all told him to shut up and gave him some urine. Opie was sent home, I don't know why but I can guess.

TDD

I got my first eyeglasses when I was six and starting the first grade. When the optician put my glasses on me for the first time, I looked around and said "Wow, that's where all that noise is coming from!"

TDD

I find the UAVs to be a fascinating technology but I can't wait for the UCAVs, that's going to be mind blowing in more ways than one. I know there is a lot of stuff going on that us lowly civilians don't know about but by gleaning information from technical publications and little announcements by defense contractors I can guess at what's coming.

TDD

Us blind people need 3 foot wide prints. Unless there is so much crap on it that you still need a magnifying glass.

I can understand your concern with the reflow soldering during the manufacturing process, I'm sure that over the years you've had to repair a lot of equipment with a problem as simple as a bad solder joint. When I worked at a repair depot, the majority of the repairs had to do with cold solder joints. I saw some of the strangest problems. One day I had a UHF receiver that wouldn't work, after a lot of butt scratching, I determined that a transistor was adding capacitance to the circuit, the transistor tested good with a good transistor tester that measured gain, leakage and whatnot but not in the RF section of the receiver. I don't know what could have caused it because I'm sure it was working when it left the factory. Plated through holes on double sided and multilayer circuit boards were another nightmare at the repair depot. With your involvement in the RBC2000, I'm sure there are multilayer boards in it, how did you address any potential problems with connections between the layers?

TDD

Oh, that's the combiner part! I see how it works now. Back in the good old days when I did a lot of two way radio work both commercial and CB, I would show people why their fancy antennas didn't work so well with a simple field strength meter. The more antennas the better, right? Wuts a lobe? Wadaya mean the signal is going that a way, I ort to be able to get out reel good with all these dang new Super Dork Snorkel antennas!

TDD

I had a few souvenirs from the dump and one of them was an iron core memory module that was small enough to fit in a missile. I think I lost it in a move. Darn it, it was a cool item.

TDD

My friend Don, a retired US Marine master Sergeant wouldn't find that funny. He was a construction engineer. They built buildings, roads, bridges and a lot of other things. They used everything from simple hand tools to heavy equipment.

I liked what happened when one guy had to see the head shrinker. The first words of the his mouth was "Why do you hate your mother" The guy laughed and said, "My mother is OK, but your mother is a lousy lay and still owes me %50". The shrink threw a hissy fit and demanded that he leave, right now. :)

I was in the fifth grade when they finally listened, that I couldn't see what was on the chalkboards. For years the teachers claimed that I was lazy, and just didn't want to read them.

Yes, some is amazing, but I had to leave manufacturing in late 2001 due to failing health. I really miss being able to work with state of the art designs. :(

Regular print on 'D' sized sheets. First generation copies from the original, signed off drawings. No blueprints, we had a huge copier. We created some test procedures and assembly drawings in color to simplify parts of the manufacturing process.

We had two problems. The size of the solder balls was too coarse when we moved from 1206 to 0805 and smaller, and the flux was wrong for fine pitch SMD in our original paste solder. It took several samples before we found what we needed. Then I had to slip in a sample roll of .015" Ersin rework solder for the hand soldering. A lot of the ICs were on .015" center to center lead spacing. That took a very steady hand, and stereo microscope. After rework & the ladies in assembly found out about it, they had to buy some for everyone, and bought over $1500 worth. The head of Manufacturing Engineering was really pissed at me. :)

Be glad you didn't have to troubleshoot hand built prototype boards built by engineers. :) Some transistors can be damaged but not work in a real circuit. ESD damage can cause all kinds of problems. RF FETs are a real pain at times.

There are different thicknesses of plating for PTH boards. Most manufacturers use the lowest grade to save money. If it's a double sided board it's not hard to run a piece of Kynar Wire Wrap Wire to bridge an open trace, or run it through the PTH and solder it to both sides.

Any defective vias, and the boards were scrapped. The VME cards were

17 layers. We paid damn good money for 100% testing, and the OEM was liable for the cost of boards that were found to be defective after they were stuffed. A couple boards cost $8,000 to manufacture, stuff & test.

--
Offworld checks no longer accepted!

I told a young lady dispatching for a corporate repair service we do service calls for that I wished I was 50 again. I started having some circulation problems with my legs back around 2000 or so due to high blood sugar. I fixed the blood sugar problem but I'm still working on the damage that was done. There's no way I could hold down a regular

9-5 job because of the pain so I work as hard as I can when I can. I refuse to take pain meds when I'm going to be driving or climbing ladders, as a result, when I get home, I'm really hurting. I explain to folks that "My hair hurts, my toenails itch and my eyeballs are squeaking." That makes it hard to get any sleep. I ran a couple of service calls today that had me on my feet for 6 hours or so and I'm paying for it now. I refuse to just lay down and do nothing because if I did, I'm sure I'd wither away so I keep on trucking. Hell, it only hurts when I quit moving!

I'm used to working on stuff I've never seen before. Heck, I sometimes think if a flying saucer broke down, somebody would call me and ask me if I could fix the darn thing. One thing that really burns me up is when I don't get called first, "Oh this guy was cheaper but he couldn't fix it." I was straightening out a computer system for a trucking company a while back and the fellow told me he had to get some billing out and didn't have time for me to finish up. I told him "This data is corrupt, whatever you do, don't try to open this application, DON'T CLICK ON THIS." You can guess what the idiot did. I had spent hours getting that system back up.

I remember years ago, I repaired a 20kw Delco generator on a crew boat that had a narrow range thermal intermittent problem with the voltage regulator. It wouldn't work when cold, it wouldn't work when hot. It would only work when the temperature was around 85°F. I pulled the regulator assembly, took it to the island TV repair shop where I set it up to bench test it and discovered a defective FET. There was no exact part available so I tried one meant for a TV set and the darn thing worked great. I've seen a lot of narrow range thermal intermittent problems in solid state engine control systems for some odd reason. Once again, this was something I'd spent hours working on because there was no replacement within 2,300 miles. The boat developed a cooling water leak on one of the V12 diesel engines and when the boat captain told the superintendent, the boss said "Screw it, run it till it quits!" The leak got worse and sprayed salt water all over the generator and that electronic regulator I'd spent so much time repairing. I don't know if you run into or have experienced this sort of nonsense in your career but doggone it seems to happen to me much too often. It's very frustrating to work your butt off to fix a problem and have someone come along and destroy all your hard work.

I hope your health improves and you are able to pass on your expertise to a younger crowd of techies because I'm afraid that discrete component board level repair is becoming a lost art. I wish I had a kid to whom I could pass on what little I know and the kid could take that knowledge and expand upon it and pass it on to others. I remember when I was a kid and being desperate for information on how things worked. I was always getting into trouble for taking things apart.

TDD

There is no reason for your symptoms. Medicine today has a huge arsenal of pain-relief medicine.

Consider the first five seasons of "House." Dr. Gregory House ate Vicodin like gumdrops and still managed to direct others in the operation of complicated machinery (CAT-scan machines, spoons, etc.) while he, himself, drove a motorcycle back and forth to work.

A fairly new drug, Lyrica, has been found effective against diabetic neuropathy. It causes some people to walk into walls, so be careful, but the hallucinations are worth it!

HeyBub wrote:

I have a drug problem or more correctly, I have a problem with drugs. I don't like taking anything. I'm very resistant to anyone or anything controlling me. The same goes for for being dependent on anyone or anything. I don't like anything that interferes with my control, dulls my senses or alters my perception of my environment. Back in the good old days, my fellow Hippie Freak friends thought I was weird because I've never consumed an alcoholic beverage in my life, never smoked anything legal or illegal or taken any illegal or recreational drug. I won't take anything unless I know what it is because I've had physicians damn near kill me with drugs. That's the psychological component of my drug problem. The physiological component of my problem with drugs causes medical practitioners look at me like I was a Martian. Drugs don't work on me as they do other people. The dosages of pain medication it takes to have any effect on me will put a "normal" person in a coma. This has doctors thinking I'm some kind of drug addict when in fact, I'm not taking anything. The last time I was in the hospital I was being tortured with tiny doses of pain medication and it's impossible to get the medical staff to understand. My physician friends are so terrified of the DEA that they are reluctant to write prescriptions for high doses of pain medication because it would make them appear to be drug pushers. There are drugs that work for me but I don't like the way they make me feel in the doses that affect me. I'll never understand people who will purposely take something that alters their mind or turns them into Jello, it's beyond me. Oh, I like the TV show "House" but it's a TV show not real life. I've seen too many lives, careers and businesses ruined by drug addiction. The show did give a somewhat true depiction of a high functioning drug addict but it's still just a TV show.

TDD

I hate soldering surface-mount stuff by hand, though - and doing those kinds of repair only works when it's not some unobtainable custom part that's failed.

Personally I'd much rather electronic stuff was twice the size (like it used to be), but at least easy to fix - but I'm in a minority there and most folk want stuff as small as possible and who gives a crap when it breaks as they can just buy a whole new one... :-(

cheers

Jules

I take Gabapentin for Diabetic neuropathy. I haven't seen any side effects, and it allows me to use my left hand for my cane without losing the feeling. The same for driving. At one time I couldn't drive more than ten minutes without losing the feeling in both hands. It doesn't alter your mood, and isn't addictive. All it does is that the edge off the pain so you can function. It comes in different dosages. The only thing I don't like is that you have to take it three times a day so there is a small amount in your bloodstream at all times. It takes a little while to work, so you can't just pop a handful and expect results.

--
Offworld checks no longer accepted!