TV tower tattoos

I want that spectrum analyzer!

:-)

No you don't. It's buggy. And it has nasty 120 Hz spurs.

Hey, check out the photo gallery:

The war is over, and the Geeks have won!

Out here girls have these kinds of spurs, and dudes, too:

The Greeks have won? How'd they finagle that? Oh, wait ...

Rental? You can rent *anything* in SF.

But sometimes you get arrested while in the rental agreement process :-)

Once again, Dropbox has its own opinions about what I should post. Try this one...

Set up a crystal radio, and you could power your building off that 96ish MHz FM station!

Cheers

Phil Hobbs

That's true anywhere. SF is special, in that you really aren't always sure exactly what it is you're renting. There's no truth in advertising.

-30dBm in the FM band? That's almost normal out here. The Bass Lake Grade towers are a few miles to the west because that's the last hill towards them thar flatlands. Sometimes car radios go berserk when passing between the towers on Hwy 50.

That was just a little RatShack alligator clip lead dangling out the front. With a bit of antenna, I could certainly run some LEDs.

There must be some motor controllers or something nearby, too. The stuff on the AC line is amazing. We're in an old concrete-and-wood building, nothing seriously grounded, so everything rattles around.

Same here, when I hang one of those alligator leads onto the analyzer it lights up. Real fun is always when I measure and then brrrrruppp ... what the heck was that? Pretty soon I learned that Boeing freighters and the like lumber in with their engines near idle and call into Mather Approach, right over the building. You can only hear them when outside, sometimes so low that one can see the oil streaks under the engine cowlings. Then there are the local guys calling in left base 31 and final 31, just a few hundred feet from the lab windows. So now I have a scanner on my lab rack that I leave running while doing sensitive measurements.

Probably a VF-drive from the days of Methusaleh. I bet your water pressure elevator with that shaft where the other end comes out in China will also cause some interesting effect, only not in the shape of EMI. I can imagine some seismometers in the area picking that up and geologists scratching their heads.

Cool. The next time the Blue Angels buzz us, maybe I can see their radio gear. It would be fun to have a 30 GHz SA and see radars, too.

The elevator pump is a big old induction motor, so we only get contactor arcs from that. We have one VF drive going to an exhaust blower on the roof, and the controller was spraying 40 volt p-p ringing oscillations all over. I had to wind my own inductors and make a filter for that.

Yeah, here it is:

You can't tell in this pic, but the Irish guy who did our conduit was an artist and a genius. It flows beautifully. He dabbles with electronics as a hobby, which is unusual in that most electricians don't know much about electricity. The hackey stuff in this pic was added by me.

John

Nice, but you could have used white wire on the upper right toroid so the whole thing looks more patriotic. Bet it would have been against code though :-)

I am surprised those cores don't saturate with so many turns on there. Or maybe it's a small blower.

Some years ago I got lucky courtesy of colleagues in the diplomatic service, and scored a special visit to a US carrier that was berthed in town. Along with a few other special guests, I was allowed to wander freely around the deck and look at anything I wanted, with an (armed) marine accompanying us to make sure we didn't take photos or touch anything. The equipment inside, particularly, the choppers was fascinating. They were chocked full of huge black boxes, with big bundles of the tiniest waveguides I've ever seen branching out to enclosed antennae on the outside of the fuselage. You'd need at least a 30G specan to see the action.

Military aircraft are approaching "active skins" where almost the entire surface is phased-array antennas, used as both sensors and weapons. Cooling all the electronics is getting difficult.