Quick Question re: Inverter

Another old story. One of my military tech friends worked on high powered transmitters. At his base there was a quonset hut used by maintenance to store supplies; in this case fluorescent light tubes. There was a cat walk leading into the quonset hut, and the radio guys got the brainstorm to string an antenna wire through the trees and bushes around the cat walk and attach it to a big transmitter. They waited for the poor old maintenance man to come out of the hut with an arm load of fluorescents, keyed the transmitter, and then laughed hysterically when he tossed the now lit tubes into the air.

Your tax dollars at work.

Tom

 

Tom

Have you ever been to Thule, Greenland? Some of the stunts we did there, I'm surprised I don't have a brain tumor the size of a grapefruit

Hint: you actually can *feel* your fillings vibrate, under the right energy gradient conditions

oy

jay

 

Nope, you really don't want to know some of the more interesting antics I was up to while enlisted

 

I was there 62-63, You must have worked up by the 100yd antennas ponted toward Russia. The thread got a ways from voltages within Prius, but still the topics are interesting and it keeps me somewhat up to date, at least Platonically. Definition of a Pedant in Shakespears time was " A teacher ", I prefer that definition.:rockon:

 

I was there during the transition from the older L band AN/FPS-50 to the phased array UHF. Again, we did pull some pretty dumb stunts, but I was a lot younger back then

Did you have any experience with the "moon gater?" Hard to believe the system had so much power it had reflection from the moon. Hence, they had to "gate" the return when the moon was aligned

I had an opportunity to take a scary C-130 ride to one of the abandoned DYE sights on the cap, DYE 2. I think DYE 2 had been abandoned for around 3-5 years when I saw it

 

No, I missed that. I have flow over, but never set foot on the ice.

Now I know why you are a hairless gorilla.

Tom

 

No I was unfamiliar with moongater, we would from time to time take unauthorised trips to the water pumping site and from there hike down to the fiord, that was just below the cliff where antennas were situated. I was in CE at the time and the only place I didn't get to was where you worked, I assume they had thier own facilities, and maintenance people, totally separate from the steam ship at Mt Dundas. At the time "the techies " had set up a nice FM station, all volunteer and no comercials. I used to also take transition flights on the small trainers, over a portion of the ice cap and the Ocean.

 

Oh it was a lot different when I was there. No more of that adventurous groundbreaking spirit, more of a daily routine - it was a job, nothing more. Kind of took the fun out of it, if you want my opinion

The cliffs? Um, kinda dangerous around there. I went with a small group, and yes we were armed just in case

Speaking of steamship powerplants, did you ever see the backup generators at the AN/FPS 50 site? I can't recall now if they were Nordberg or Vivian diesels, but they were HUGE

Would I go back? Sure, if it was an "interesting" contract. I now define "interesting" as contributing to my retirement fund. At least the new buildings are way more comfy than the old ones.

I actually wouldn't mind exploring DYE 2 again. It was a bit creepy walking along those cold empty corridors, vapor coming off your nose and mouth, looking up at ceiling tiles sagging from condensation when the building initially cooled off.

There is a lot of history at the icecap radar sites like DYE 2.

 

Oh, you just wait. It's just a matter of time before your thick, luxurious hair falls out.

When it does, save it for me. I'll crazy glue it to my scalp

 

I watched a guy key a X-band transmitter at a cop holding a radar gun about 2-blocks away. After the 1-second burst, the cop shook his radar gun a few times, tried it a couple more times, shook his head, and drove off.

My older brother told a story about a maintenance man walking across the deck of the USS Enterpirse when all of a sudden, the entire box of flourscent tubes he was carrying light up brightly. The guy immediately dropped the box and ran. It was later my bro learned they guy thought it was a sign of the almighty from above talking to him.

 

No, I worked at one of the back-up, base plants. Armed? Why? //Did you ever trade with the eskimos?

 

Hi All,

Such interesting experiences you all have had.

On the Xrays things, I doubt much can come off a computating motor as the inductance of the coils would limit the rise times, and thus the peak voltage.

You may know that Presure Sensative Adhesives work by microscopic static electricity. I learned this the hardway. Masking tape can be an expensive static hazard, suprisingly.

Back to the X rays. They are commonly made by accellerating electrons into a metal target. This is why TV Cathode Ray Tubes use lead glass. The stray electrons that happen to miss the holes in the metal shaddow mask and generate X-rays are shielded by the lead in the glass.

Recently a group of researchers have taken X-ray pictures using a device that rapidly despools a roll of what looks to be heavy duty packaging tape as the source. The microscopic discharges are so energenic that X-rays are generated.

 

Oddly enough, coronal discharge losses are actually quite significant for long-haul very high voltage transmission lines. I think for typical design tradeoffs they actually become the highest loss source for the highest voltages in current use.

The coronal loss is strongly superlinear in voltage, so of two comparable lines the one carrying AC is at a substantial coronal loss disadvantage as the peakiness of the AC line voltage hurts.

As power switches and other gear involved in getting on and off the line gets cheaper relative to land and to the value of power wasted in losses, you'll likely see a higher rate of use of DC transmission.

By the way, Edison's AC/DC conflict was with Westinghouse, not Tesla. Saying he neither knew nor would learn Ohm's law is beyond silly.

 

Westinghouse and Tesla were good friends and partners. When it looked like Westinghouse was going to fail, Tesla ripped up his shares of stock or and agreement he had to profit greatly, telling Westinghouse he would not hold him to this agreement. As for Tesla/Edison and Ohms law, I'll see if I can find the book I read on Teslas Life and quote it for you. But, Authors can also be wrong. andy PS: What does a coronal discharge look like?

 

No, it was because we were a bunch of dumb noobs and the "old timers" had us believing that polar bears were prowling the corridors at "night." Remember "night" when you had to hang blankets over the windows, or you'd never sleep and get "Thule eye?"

A few of us got permission to go on a short hike, and everybody was smirking as we picked up weapons. Oh, that was so funny when we got back, all the "old timers" laughing at us. Not a very bright idea to laugh at armed men, is it?

To really give us a hard time, they'd sneak up to our rooms while we were supposed to be asleep, and make growling and scratching noises at the door. Ha ha ha, very funny.

But, after a couple of weeks, everybody became fast friends. In a closed environment like that, you had to. We did have a couple of guys flip out, they had to be sent back stateside

 

I think you're referring to Bremsstrahlung Effect. The only experience I have is with rotating x-ray tubes used for industrial inspection, these used fairly sophisticated liquid cooling systems

It should be noted that producing x-rays is a very inefficient process. Typically, less than 5%, usually around 1%, of the total energy is for x-ray production. The rest is heat

The incidental x-rays generated by static electricity are fairly low power, not likely to cause harm.

 

A lot of folks fail to realize, or simply don't understand, that when we refer to an AC voltage, say 117 vac, this is typically Root Mean Square or RMS. As the waveform is sinusoidal there is a Peak component, an Average component, etc

IMHO the single biggest advantage of HVDC power transmission is elimination of most of the EMI/EMF artifacts. There is potentially a huge health advantage to eliminating these artifacts.

With modern solid state technology, eg high power IGBT, that is now relatively cheap to manufacture, there is now an efficiency advantage as well, especially if you have to use underwater transmission.

I doubt anybody could have foreseen solid state components almost 100 years ago. The only way to rectify/invert back then was with electromechanical means, or large and dangerous mercury tubes.

 

In the lab, corona discharge can take on many forms. I've seen it as a pale glow, but usually it looks like fine whiskers. It's actually pretty, now that I think about it