JAYCAR has had them for for a while too: JAYCAR: Flux Capacitor

Unfortunately whenever I look, it's always out of stock :(

This is the closest thing to a wiring fail I could come up with yesterday:

https://cimg9.ibsrv.net/gimg/www.mia...a7953c8508.png

That's the antenna controller for one of the four steerable microwave dishes which I have on the 105th floor of Sears Tower. Note that I had already removed the paperclip which was jammed into one of the terminals and then gator-clipped to that pin that's hanging out.

The view ain't bad from up here, though.

https://cimg7.ibsrv.net/gimg/www.mia...d2f28a1ad0.png



Any EoC / MoCA gurus on here? I need to run 100 meg ethernet over about 200 feet of RG-59.

No, I can't pull a new cable, I gotta work with what I have already in place. (You don't wanna know how much red tape it takes to get a wiring permit in this building. Three men died in the process of doing the existing cable run. Well, not really, but this run scares the shit outta me. You're literally crawling over asbestos-coated structural steel I beams with about 50 feet between you and the concrete floor.)

No, I can't use a 10b-2 transciever. This is 75Ω.

Don't care how much it costs, I just need it to be utterly reliable. Actual throughput requirement is less than 1 mb/s. E-band would be preferred.

Non cable guy questions:
1) Does it need to be in conduit? If not and this is all done in an open space - why not get up in starting point, mount a pully, feed line through it, walk it to the other side, mount/terminate?
2) Can you use a rolling scaffold with remote control so you can stand in it while it is jacked all the way up?
3) go with a laser or RF wireless link between the two end points? Ubiquity will do this for you easily and will be totally reliable. I've done point to point wireless between buildings and no issues.

If it's high up and you don't want to be on I beam, then why not use a rolling scaffold from below? Or not use RG and go with

No, no, and no.

This cable run goes from the south side of the 105th floor of Sears Tower to the north side of the 104th floor. I cannot even begin to comprehend how they made the existing cable run in the first place, as it's wire-tied to structural elements of the building which are virtually inaccessible without an anti-gravity belt at many points. This is the space I'm working in:

https://cimg9.ibsrv.net/gimg/www.mia...d44bd748d2.png

https://cimg6.ibsrv.net/gimg/www.mia...3875b51912.png

https://cimg8.ibsrv.net/gimg/www.mia...bb2b766706.png


Yes, that is asbestos, and I'd rather not fuck with it. Yes, you have to be down on your hands and knees to fit through those spaces.



Running a new cable is not an option.


That said, this box looks promising: https://www.cdw.com/product/StarTech...er-Kit/2935164



Not even remotely feasible.

I'm using Ubiquity to shoot from the Sears Tower over to Hancock Tower, but this specific run is the exact opposite of line-of-sight. There are a few hundred tons of concrete and steel between the source and the rack I need to get to, and I think building management would be unhappy if I removed them. (Also, the tallest all-steel structure in the world would probably collapse, and that would make this ethernet link irrelevant, in addition to killing thousands of people and probably starting yet another senseless war.)


Because I enjoy being alive, and there's a lot of paperwork I have to fill out if I kill one of my employees which I'd rather not deal with.



With... what?

I'm not an expert on the physical layer stuff (these days I'm working on BGP, which is about as far from the phys as you can get and still be writing software for an ethernet switch/router), but there's lots of hardware out there for doing ethernet over cable TV wiring. It goes from cheap stuff from Amazon (designed for running using existing cable TV coax to run it around your house) up through cable modem DOCSIS networks.

Broadband token bus ran (802.4) over that kind of coax too, but it's looooong since obsolete. :)

--Ian

I hope that your death is agonizing and slow. :giggle:

After a ridiculous amount of time researching 6.5" subwoofers, I decided on the DS18 Elite Z6, mostly because it was the cheapest of the half-dozen "good" quality 6.5" hi-excursion subs I was looking at. Now I'm researching amps with the idea of going very small... kinda want to keep the whole package under the size of your average 24pk of soda cans. Anyways, the YT rabbit-hole led me down something other than Russian dash-cam videos for a change, and I found random engineering challenges featuring popsicle sticks. I'm surprised that Joe Perez hasn't feature a video like this in his "what interests me thread"...

This shit never ends...

I was talking about these when talking about scaffold/lift.
https://cimg5.ibsrv.net/gimg/www.mia...2ca9963ae3.png


The second part, i didn't finish before submitting.

How about Fiber that you shoot a pull run with a paintball gun?


https://cimg1.ibsrv.net/gimg/www.mia...82b9302a28.jpg
https://cimg5.ibsrv.net/gimg/www.mia...96d5bddae2.jpg


https://www.techtoolsupply.com/Laser...21010-9-v2.htm

I was JUST going to suggest that. Beat me to it. Laugh all you want but I've used something similar but a little more homemade before before.

Hehe.

We had something like that in high school. It was a tower, not a bridge, but same basic idea. The tower was judged on a combination of total height and the weight that it took before collapsing.

A friend of mine, who went on to be an ME, took a very creative reading of the rules, and constructed a tower that was about 1" tall and 6" in diameter, with a little arm sticking out the side which was about 4 feet tall. (Taller than would fit into the press being used to test with.)

This was obviously disqualified (he didn't expect it to be let in), so he also constructed a second tower, which was more conventionally in line with the spirit of the rules. The teacher ran out of weights without breaking it, so he went out to his truck and brought back a scissors jack.




To get into this space, you have to crawl through several openings like this:

https://cimg3.ibsrv.net/gimg/www.mia...d603048dbf.png


And then once you're there, you're working in spaces like this:

https://cimg9.ibsrv.net/gimg/www.mia...4fded8a60c.png

It kinds feels like you're inside the videogame "Portal" after the part where you escape the victory candescence. No way in hell you're going to fit a lift in here.

I gotta say, it fills me with a sense of awe as to how the building engineers service some of the gear up here.

https://cimg2.ibsrv.net/gimg/www.mia...e3b80991f7.png

These pumps and motors are huge in the extreme, and they're got nothing up here but chain hoists and some furniture dollies.




It possible that if you were to train a rat to crawl from one end of the room to the other with a pull-cord tied to its tail, you might be able to do it. But there's nothing even resembling a straight shot. It's all twists and turns around a combination of piping 6-24" in diameter, HVAC ducts, and lots of structural steel. Here's one pic of the existing cables (top-right):

https://cimg8.ibsrv.net/gimg/www.mia...8aed588619.png

They make a hard right just after the pipes, as one example of the challenges.




Image unrelated:

https://cimg0.ibsrv.net/gimg/www.mia...cbabca2e26.png

https://www.miataturbo.net/attachmen...1&d=1520794171

https://www.miataturbo.net/attachmen...1&d=1520794171

When I was on Nimitz, I got to take a tour of the reactor spaces... makes your pump room there look roomy and manageable. There are parts within the ship that are designed to last the lifetime of the ship and cannot be removed without cutting the ship open during an extended yard period (I'm talking about a year-long project) in dry-dock. I remember one of the Nukes saying that several parts within the main gearboxes/transmissions aren't even owned by the Navy. We rent them for 50yrs from General Dynamics or somebody so that they are on the hook to pay to replace them (which isn't possible) if they ever break.

This picture is of a couple of the main diesel generators. I think the ship has 4 of them. 3 are to provide power to the ship if the reactors go offline... the 4th one is there strictly to power water pumps to keep the reactor flooded in case something really bad happens. Some of the seawater intake pipes are big enough to drive a sedan through.
https://qph.fs.quoracdn.net/main-qim...719eb5b95d59-c

https://upload.wikimedia.org/wikiped..._July_2014.JPG

How about a TOW missile? It drags a fiber line, and will take care of any obstructions in its way.


https://cimg6.ibsrv.net/gimg/www.mia...4a794d65a5.jpg

Joe, how about a small drone/remote control helicopter pulling a fishing line?

Pics?

(hehe.)


Yeah, I know what you mean. While I was working at Meyer-Werft, I got to see an engine being installed in a cruise ship. They assemble the ship up to a certain point, then they install the engines (and switchgear, and propulsion motors, etc) and then they assemble the rest of the ship around the drive gear.

Not my photo, but one of the two ships I outfitted. Hull # 687, The DCL Dream:


https://cimg5.ibsrv.net/gimg/www.mia...b5eee76f4d.png

https://cimg0.ibsrv.net/gimg/www.mia...e43ad26437.png






https://cimg2.ibsrv.net/gimg/www.mia...f06248db62.png





Watched that whole thing last night. Amazingly cool how they designed that airplane (and its shipping container) so that nothing was wasted.







A tidbit from the officers' wardroom aboard the QE2:

https://cimg1.ibsrv.net/gimg/www.mia...701322a3ba.png

Inscription reads "Echo diesel engine at 27469 hours 11th June 1992 R.I.P. Ripped itself to pieces."

Only a little over three years of continuous running. Is it just me or does that sound low?

If you ever have the chance, check out the Henry Ford Museum in the suburbs of Detroit. There are some monster engines on display there. It's really probably one of my top three museums ever.

It's a surprisingly low MTBF, but it fits the ship's timeline. QE2 was originally powered by oil-fired boilers and steam turbines. She was converted to diesel during a major re-fitting in 1986-87. So those engines were only about 5 years old in 1992.

I have no idea what caused the failure.



Another interesting vessel, the NS Savannah


https://cimg4.ibsrv.net/gimg/www.mia...704d168b49.png

https://cimg2.ibsrv.net/gimg/www.mia...2ad8538669.png

https://cimg2.ibsrv.net/gimg/www.mia...d7edb641a1.png

https://cimg7.ibsrv.net/gimg/www.mia...1664f1e14c.png

Watch until the end

click to play

If you come to Detroit and don't at least spend a day in greenfield village, you're really missing out. It's where i recommend everyone go if they're visiting the city.


Trying to keep with the theme. Might be repost.
https://cimg0.ibsrv.net/gimg/www.mia...5b1d1eaeb0.jpg

I haven't been to Greenfield village. Both times I have been to Detroit it's been before Greenfield opened for the year.

The museum is in / at the village, if it's off season you can still get into the museum.
Anna scripps whitcomb conservatory, Dossin museum, fisher building, DYC, tons of bars, restaurants, shopping centers and many other places are all original and preserved.
Despite what people may have lead you to believe, Detroit hasn't entirely crumbled to the ground.

https://cimg1.ibsrv.net/gimg/www.mia...cdf050043a.jpg

^ Looks fairly clean, for an aftermarket harness.


In other news, it turns out that you can purchase a 5 lb box of duck heads for $101.63 on Amazon.


https://cimg2.ibsrv.net/gimg/www.mia...277c782739.png

Sadly, they are furnished without tongues. This led me down a whole other rabbit hole, and it turns out that duck tongues are apparently pretty delicious.

Is that Troll Systems? Looks like the ones we installed, but ours were modified for on the move adjustment.

Attachment 219941

You earn a :likecat: for that.

Yup, Troll X750, slaved to an S750, just like the ones in your photo. MRX4000 receivers and TMF350 filter controllers, all driven by an array of TouchStar workstations.


https://cimg8.ibsrv.net/gimg/www.mia...e36881671e.png


Not sure what you mean by "on the move" adjustment. Something like NavTrack?
https://cimg7.ibsrv.net/gimg/www.mia...b0b3e9c123.png

The photo is of the tower system. The vehicle system is a little more interesting, but I couldn't take pics since there was classified stuff inside. It was a similar setup to a TV van. Drive out and park, then push the button to get your microwave backhaul. You could select which tower and auto-align the dishes. While the vehicle would track while moving, the tower didn't. You had to set the coordinates manually on the tower. This was in like 2008, so the technology was fairly infantile for them. The magnetometer didn't like to stay calibrated very well.

Attachment 219942

Yet they're still smiling.

Huh.

Troll has a system called NavTrack which does basically that job, but better. We have it on our helicopter. A GPS receiver at the transmitter figures out where it is, then encodes this information onto one of the audio channels. At the receiver, it decodes this and, knowing where it is (if the receiver is moving, you'd best run away from the tower quickly), points the dish in the correct direction in both azumith and elevation.




They're happy ducks, man...

https://cimg7.ibsrv.net/gimg/www.mia...b48dcb0edb.png

My first thought would be to remove the connector, make a plate to hold the strain relief, and hardwire the line into the circuit in the box.

Que?

I can easily enough just put a new back-shell onto it. The bigger problem is what all the rest of the wiring in that rack looks like. It's shameful frankly...


https://cimg6.ibsrv.net/gimg/www.mia...0ffc159374.png

That looks worse than under/behind my desk. And I am not touching anything unless I need to do so.

Yeah. And my biggest fear is that if I knock something loose, WGN loses most of its field news-gathering capability.


And now, a riddle.

Q: How much bandwidth is this?

https://cimg5.ibsrv.net/gimg/www.mia...d875f7163e.png

A: It is a lot of bandwidth.

Not as much as I'm sitting on here. :)

https://photos.smugmug.com/Arista/Ar...MG_7101-XL.jpg

--Ian

Sounds like something you send to someone as a threat - much cheaper than a horse head!

Meh, that pales in comparison to the Brocades we installed for NASA.

We had a bunch of these fully populated with 10G cards and the requirement was some ridiculous 1 packet per day of loss, all multicast traffic. We had to do a lot of work with Brocade to make it meet the requirement.
https://images.duckduckgo.com/iu/?u=..._mr_42.jpg&f=1

10G? The chassis I'm sitting on will take 288 100G interfaces and has 75Tbps of switch bandwidth. We make one double that size too, but it's too tall to use as a stool. :)

--Ian

We have a winner:

https://cimg1.ibsrv.net/gimg/www.mia...65f08adf89.jpg


Also:

https://cimg9.ibsrv.net/gimg/www.mia...9b268ee4fa.jpg

Our system couldn't send to the tower. I can't remember exactly why, but I think it had something to do with the radios they were using for that at the time. The spectrum was probably in a bad range. I don't think they had in-band back then, either. Also, it was a different use case since they weren't going to keep the thing running while on the move. Just park and setup. It's much easier on an aircraft that's not bouncing around through a desert. The rack in the vehicle exceeded all our estimates for shock and vibe. The suspension wasn't rated correctly for the weight of the container.

Found some pics
Attachment 219943Attachment 219944Attachment 219945Attachment 219946Attachment 219947

Can't really tell what it is from the pic. Doesn't look like 100G interfaces.

I'm not sure what the one in the photo is loaded with, we shot it a while ago.

It's an Arista 7508 chassis, there have been a few different revisions of it along the way.

--Ian

https://cimg0.ibsrv.net/gimg/www.mia...eeceb763c3.png
https://cimg2.ibsrv.net/gimg/www.mia...dff29da589.jpg
​​​​​​​

Too soon?

https://www.miataturbo.net/attachmen...1&d=1521058547

Steven Hawking was smarter than all of us here combined. Respect to a brilliant man who who could understand and work with concepts most of us will never be able to grasp fully. I have at least one of his books and read a number by others where he played a very important role in understanding how universe works. He was told that he wouldn't live past 25 years of age and even though he became wheelchair bound, unable to do most things humans take for granted - he continued working on advancing our understanding of this world. Laugh all you want, but it is a sad day for humanity. We were lucky to live with the equal of Einstein.

His wish for the tombstone was to have "Hawking’s equation" written on it - a formula for black hole entropy.

what if, he actually wasn't that smart, but since you can never really test his formulas and they are so complex, everyone just smiled and nodded?

Understanding that there is a problem with quantum particle-antiparticle pair at the edge of the event horizon, which leads to black hole information paradox was more than anyone else was able to do on the subject. He first formulated the concept of information (radiation) escaping black hole and shortly before his death proposed a solution to this problem. His formulas are not super complex, other scientists understand them and can apply appropriately. There is nothing to say that they can never be tested. Just like humans are able to find planets outside of our own galaxy or tell the predominant composition of planets on the edges of our galaxy without ever seeing them with our eyes, taking a soil sample or using ground penetrating radar, we may be able to verify the solution without having a black hole in a test lab.

https://scontent-ort2-1.xx.fbcdn.net...e0&oe=5B00C938https://cimg6.ibsrv.net/gimg/www.mia...6e85a306e9.png
https://cimg7.ibsrv.net/gimg/www.mia...c239b4fecf.png
https://cimg8.ibsrv.net/gimg/www.mia...d808fddb3c.png
https://cimg9.ibsrv.net/gimg/www.mia...4e8342b092.png
https://cimg0.ibsrv.net/gimg/www.mia...24f636aa9e.png
https://cimg1.ibsrv.net/gimg/www.mia...72812002d0.png

We've been moving away from the "one big central switch" concept towards a more distributed approach. This is the hardware for the current phase of the project:

https://cimg2.ibsrv.net/gimg/www.mia...d272073a77.png



A few of them installed and running in a different room. This pile replaces an old Catalyst 6500.


https://cimg5.ibsrv.net/gimg/www.mia...256e7c0a2d.png