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This is the closest thing to a wiring fail I could come up with yesterday:
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.
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 **** 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.
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 **** 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
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?
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:
Yes, that is asbestos, and I'd rather not **** with it. Yes, you have to be down on your hands and knees to fit through those spaces.
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.
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.)
Originally Posted by 2slow
If it's high up and you don't want to be on I beam, then why not use a rolling scaffold from below?
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.
Any EoC / MoCA gurus on here? I need to run 100 meg ethernet over about 200 feet of RG-59.
...
Don't care how much it costs, I just need it to be utterly reliable.
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.
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"...
I'm surprised that Joe Perez hasn't feature a video like this in his "what interests me thread"...
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.
Originally Posted by 2slow
I was talking about these when talking about scaffold/lift.
To get into this space, you have to crawl through several openings like this:
And then once you're there, you're working in spaces like this:
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.
These pumps and motors are huge in the extreme, and they're got nothing up here but chain hoists and some furniture dollies.
Originally Posted by 2slow
How about Fiber that you shoot a pull run with a paintball gun?
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):
They make a hard right just after the pipes, as one example of the challenges.
These pumps and motors are huge in the extreme, and they're got nothing up here but chain hoists and some furniture dollies.
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.
03-09-2018, 07:30 PM
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