How fun! Once, after climbing around in a dusty old church attic like this, I had to head straight to the airport for a flight. Barely made it on because something in the dust kept flagging as dangerous. They were using a test strip on my backpack and clothing and analyzing it in some kind of machine. Stressful as I was already pressed for time! Finally got a clean test and they let me through.
Ion mobility spectrometry is the tech that powers these, and they're VERY sensitive and VERY prone to false positives because it's just looking for ion signatures ("I smell a nitrate/glycerin/etc."). I'm not sure if they're changing modes on the machines between swabs or something, but the machine is a cue for more in-depth inspection, not "zomg I found a bomb". So, some repeated scanning to rule out a false positive or burn off gunk that's accumulated in the machine i.e. we just got a speck of something on the wand or something is gunking up the scanner as opposed to "someone covered in residue that is scary".
Shortly after 9/11 I was flying out of Hawaii back to the mainland and I watched the screen when they swabbed my bag. It reported as positive for every single type of explosive (to the best of my knowledge, I was not carrying anything even remotely explosive). The tech looked at the results, said "that can't possibly be right" and waved me on.
If this was in the US, it's all security theater. Basically if you get flagged, they swab everything in your bag to find what's getting flagged, and if it's legitimate they pass you through, or they keep swabbing you if its just your hands/arms because they also inspect your bag. It's kind of dumb, but also kind of makes sense.
For extra fun times, baby wipes / wet wipes get flagged as explosives in the US when they use the sniffer devices.
I will be the first to join you on "most of TSA is security theater"; the baby wipes are glycerine getting flagged by ion mobility spectrometry. The machines are fast because they just look for basic chemical building blocks, not doing full spectrometry to figure out the whole compound. So glycerin, nitrates, etc. set it off (and someone else's sticky glycerin e.g. sunscreen can gunk up the machine for multiple subsequent people).
The battery on that circuit looks very much like a backup battery we have connected to our house alarm.
We moved in to the house in 2003 and that battery died this year, so I would imagine that it is already or will very soon die. That said, if it's a backup battery and the electricity supply is stable then it may not make any difference.
Design spec is up to 5 years. The one in the photo looks like it may have a date written in Sharpie on the side. I don't think it's 25 years old though. The "090323" on top could be DDMMYY indicating a battery from 2023.
I agree with the 2023 decode there, but there is still a bit of a puzzle:
If someone knew to replace the battery just three years ago, I would expect they also would have enough knowledge to set the clock itself. Or at least explain what was going on. Maybe this person isn't connected with the building anymore. But I would expect the new owners would be able to contact the old owners for help on this instead of sending a generalized call for help.
> The "Status" LED flashes some kind of code - long long, short short short. I assumed the number of flashes would correspond to the time but apparently not. We didn't have time to figure this out before we had to leave.
long-long-short-short-short is 7 in morse code. They don't say what time they tried this or if it ever changed, though, so that's just a hypothesis.
It's almost certainly this. I suspect the advance button can be used to advance the time via morse code LED flashes and only then committed when you get to the right hour.
Perhaps the long-press commits the hour, which is why it rang once initially.
Fred Dibnah was a treasure. If you enjoyed 5 minutes of Big Ben, here's an hour of his day job in heavy industrial steeplejacking - "The Ups and Downs of Chimneys" https://www.youtube.com/watch?v=KK2wF_-yoEg
I just got to tour Big Ben in July when I visited London. The mechanism is an amazing piece of technology and the precision achieved at the time of development was crazy. Also being able to stand next to the bell as it rang was truly an awesome experience.
Fred Dibnah's steeplejacking videos are awe-inspiring and a little bit horrifying. Fred seems like he was quite a character. I definitely recommend watching any videos he was involved with.
What a lovely blog in general: some really fun retro-computing projects, written up in a very thoughtful, human way. Feels like a throwback to the earlier hacking spirit of the internet. Thank you, Colin: your "experiment with writing" is a success as far as I'm concerned!
Was just reading one of his posts earlier while having lunch, only a few miles from that very clock tower, the one in the post here. Other side of the capital!
Gorgeous building and a nice wee pub across from it! A couple of friends of mine used to stay not far from there.
I've half an idea I did some networky stuff for the Community Wardens probably around the time that chime box was fitted - if you see anything marked Alvarion or Ceragon, it's probably got my real name on it somewhere.
I'd love to poke about in there some time, maybe if I'm down in that part of the world I can jump in and volunteer to help too.
Yeah I repair old cameras these days. The amount of cameras I've fixed by just poking at random stuff until it unjams is surprisingly high. Even more so the number I've "fixed" by just replacing the batteries.
Seeing the number of holes in that ceiling I really am concerned that the floor the clock is on is the same as the one with the holes, and I would advise that you secure the floor if you return to the attic.
There's a non-zero chance the "floor" is just plywood laid across some of the beams and the holes are from people missing the beam in areas there's no plywood
Shortly after 9/11 I was flying out of Hawaii back to the mainland and I watched the screen when they swabbed my bag. It reported as positive for every single type of explosive (to the best of my knowledge, I was not carrying anything even remotely explosive). The tech looked at the results, said "that can't possibly be right" and waved me on.
For extra fun times, baby wipes / wet wipes get flagged as explosives in the US when they use the sniffer devices.
We didn't put it at #1 though! That is a confirmation that we made a good pick.
badoosh
....I'll see myself out
We moved in to the house in 2003 and that battery died this year, so I would imagine that it is already or will very soon die. That said, if it's a backup battery and the electricity supply is stable then it may not make any difference.
https://www.rapidonline.com/yuasa-yuvolt-yucel-y1-2-6-valve-...
https://static.rapidonline.com/pdf/18-5207_v2.pdf
Design spec is up to 5 years. The one in the photo looks like it may have a date written in Sharpie on the side. I don't think it's 25 years old though. The "090323" on top could be DDMMYY indicating a battery from 2023.
If someone knew to replace the battery just three years ago, I would expect they also would have enough knowledge to set the clock itself. Or at least explain what was going on. Maybe this person isn't connected with the building anymore. But I would expect the new owners would be able to contact the old owners for help on this instead of sending a generalized call for help.
long-long-short-short-short is 7 in morse code. They don't say what time they tried this or if it ever changed, though, so that's just a hypothesis.
Perhaps the long-press commits the hour, which is why it rang once initially.
I didn't build the chime box but it looks like the sort of thing I used to do back then.
Fred Dibnah was a treasure. If you enjoyed 5 minutes of Big Ben, here's an hour of his day job in heavy industrial steeplejacking - "The Ups and Downs of Chimneys" https://www.youtube.com/watch?v=KK2wF_-yoEg
https://www.youtube.com/watch?v=kl_UA36ouzM&list=PL2vJ5Cg-wl...
it's literally kittycorner from City Hall, and hasn't been running for a while...
i'd do it for free if i knew who to even bother about getting up into it
https://www.reddit.com/user/dingdongbellguy/
https://www.youtube.com/@DingDongitsthebellguy
He also posts on reddit under dingdongbellguy
I've half an idea I did some networky stuff for the Community Wardens probably around the time that chime box was fitted - if you see anything marked Alvarion or Ceragon, it's probably got my real name on it somewhere.
I'd love to poke about in there some time, maybe if I'm down in that part of the world I can jump in and volunteer to help too.
There were three identical street clocks in Edinburgh that the council there have tried to remove. They succeeded with the one at Tollcross.
sometimes you get paid because you know things, sometimes you get paid because you know how to figure things out.