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>> No. 26527 Anonymous
23rd April 2018
Monday 4:54 pm
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I really want an old rotary telephone. I remember using one at my nan's as a kid and the tactility is so satisfying.

Does anyone knows if BT/Virgin still support pulse dialling? My plan is to buy one anyway and convert it to USB using a PIC/Arduino/Pi/Whatever to use it as a VoIP dialler, but it would be nice if I could also connect it to the real phone network.
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>> No. 26528 Anonymous
23rd April 2018
Monday 5:40 pm
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BT still support pulse dialling, but Virgin and most Openreach providers don't.

You can buy a pulse dialling to DTMF conversion kit for £25. Soldering is required, but the seller does provide an installation service. An Arduino library is available for pulse to DTMF conversion; it'd be a simple project if you have basic experience with the Arduino platform.

>> No. 26529 Anonymous
23rd April 2018
Monday 5:47 pm
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I haven't tested in a few years but to the best of my knowledge the Erikson/ System Y exchanges used by ALL local loops (that bit of wire that connects you to the local exchange, which is what those big old green boxes are. If people knew they contained 100 grand of kit they'd go missing like crazy.

Anyway afaik they still support pulse dialing as legacy, replacing the old GPO/BT local loop exchange system just to remove pulse dialing would have been, in my fat old beardy man opinion, financially unfeasible.

Where you'll run into problems is tone based option dialing stuff, calls outside your local 10,000 number exchange (0207 123 xxxx), international and so on.

Pulse dialing is really an anomaly, the whole global phone network ran internally on tone dialing from the 60s through to the 90s. Everything's going digital now and most mobile operators just use TCP/IP to connect everything that has to go via cable (and sometimes via radio).

Anyway bla bla for rambling on old phone tech. No one cares about.

Ps: In Majorca (Palma, not Magalug) I saw a functioning old switchboard in the hotel I was staying at, I couldn't convince them in my A-Level spanish to let me have a poke at it. Can't say the same about the receptionist though, so swings and roundabouts.
>> No. 26530 Anonymous
23rd April 2018
Monday 6:52 pm
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I have something a bit like this. It doesn't spin, but it does have a very pleasing mechanical ringer. Would that do, or do you need to go full hipster with an actual rotary dial?
>> No. 26531 Anonymous
23rd April 2018
Monday 7:04 pm
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Cheers, lad. I was planning on making one myself if they didn't already exist.

Thanks, I guess I'll try it out and see.

PS: Getting /emo/ here but as a permavirgin I can't fathom how it seems so easy for others. To me, getting laid seems like more effort than climbing Everest, but apparently it's like breathing to most.

That's just a phone that looks rotary bit isn't, surely that's /more/ hipster as it's emulating an old design for no good reason?
>> No. 26532 Anonymous
23rd April 2018
Monday 7:20 pm
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I'm no expert, but my understanding is that most exchanges have been substantially upgraded in recent years to support VDSL. As part of this process, the old line cards, AXE switches and DSLAMs have been replaced with MSANs, which backhaul both voice and data over IP. BT's MSANs do support pulse dialling, but LLU providers use their own MSANs which may or may not support it. I've heard from one source that loop disconnect is theoretically supported by all providers, but they've tightened up the timing requirements to prevent accidental calls to 112.
>> No. 26533 Anonymous
23rd April 2018
Monday 7:22 pm
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> BT still support pulse dialling, but Virgin and most Openreach providers don't.

Interesting. Did they pull out all the mile of copper wire in the local loop and replace it with fiber optic cable or something?

All BT's old (still in use, afaik, please correct me) exchanges (System X, AXE10 (System Y), 5ESS (There's at least 1 still at Upper Thames Street. I mean it's in situ I don't know if it's in use)) all support pulse dialing on the local loop so you should be able to call all 1000 numbers on that exchange. Exchange to exchange communication is, as far as I know, all CCITT7 these days so you may have trouble calling someone on another exchange.

Unless, like I said, Virgin and Openreach and whoever else pulled out all the copper wired local loop and basically turned your home phone into a VOIP line with emulated tone dialing software running on whatever Windows box they're using as an exchange.

As a (fellow?) enthusiast I would like as much information as possible please.

OP I apologise for hijacking your thread and otherlad please feel free to open a new "Current state of the UK phone network thread" here in /g/ if you feel like sharing your knowledge.
>> No. 26534 Anonymous
23rd April 2018
Monday 8:59 pm
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My understanding of the situation is as follows.

The old system (retroactively named 20CN) was designed for voice and had DSL retrofitted into it. A combined highpass/lowpass filter splits the signal from the copper loop. The voice frequencies are fed into the existing PSTN exchange equipment (system X/Y), while the higher frequencies are fed to a DSL access module.

The new system (21CN) terminates the copper pair at a Multi Service Access Node which does everything digitally. The MSAN provides whatever services are needed to each local loop customer (POTS, ISDN, xDSL) and connects to the backhaul network using standard Ethernet. The customer's analogue phones work as usual, but the MSAN converts the analogue signalling into VOIP. From this point on, it's all fibre - smaller local exchanges connect to Tier 1 exchanges, which connect to Metro nodes, which connect to Core nodes, which connect to the rest of the world.

Telecoms providers can use any amount of this infrastructure, depending on their needs.

>> No. 26535 Anonymous
23rd April 2018
Monday 9:43 pm
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>OP I apologise for hijacking your thread

It's alright, something I've always been surface-level interested in but never looked into in much detail. Born in the early 90s, I only remember the tail end of total reliance on the phone network and so how it all works is pretty interesting.
>> No. 26536 Anonymous
23rd April 2018
Monday 11:06 pm
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With that, I was aware of Cap'n Crunch and the 2600Hz tone in the US, but not really anything about Phreaking in good old Blighty.

Came across these articles from the 70s, interesting read even if I didn't quite get every term:
>> No. 26537 Anonymous
23rd April 2018
Monday 11:07 pm
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30 years ago, I remember my friend showing me that you could dial just by tapping the off-hook button, with a pause between each number. You could test it with 17170 or something.
>> No. 26538 Anonymous
24th April 2018
Tuesday 12:22 am
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It's 17070, and AFAIK that number is still in use. I think it might have other functions, but the two things most people would use it for are the ringback and the quiet line test.
>> No. 26539 Anonymous
24th April 2018
Tuesday 2:18 am
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Outstanding info there. Any idea who builds/sells these MSANs and how one might get old of the specs and user manual for such a device? System Y/X was a pain (worse than 5ESS and far worse than DMS 100) in terms of remote access because the MMI was basically physical. I'm asuming MSAN's probably have a remotely accessible IP address that may or may not require access to a vpn (not saying I'd jack a signalman's handset but yanno maybe my mate Micky Mouse would).

Bigupz to the Darkcyde crew this goes out to F41th z1ne and all who remember her ... 2 hours of modem noises with Hybrid spitting bars over the top to a drum and base beat.... oh my daaaaays
>> No. 26540 Anonymous
24th April 2018
Tuesday 2:25 am
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Modern (LOL) UK stuff from when I was into this shit in the late 90s

MED did a 3 part guide


There was also part 3 that covered the physical locations of major BT switching systems and back doors that the cleaning lady sometimes left unlocked or something idk.

Anyway my favourite file of all time is called "The Secret(s) of the little blue box" by Ron Rosembaum. Find it. Read it. If you can't find it I'll find it for you.

Mate, at the end .... when he says "but did you ever steal anything?" ...... 'Then you know! You know the rush you get!" ..... if that doesn't make you tingle then well..... I'm a fat beardy hacker nerd geek and you're not.
>> No. 26541 Anonymous
24th April 2018
Tuesday 2:55 pm
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BT are using Fujitsu Geostream MSANs, but good luck finding documentation in the public domain.
>> No. 26542 Anonymous
24th April 2018
Tuesday 7:34 pm
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But isn't this all a bit out of date now?

I might be talking complete bollocks here, but my understanding is that if OP is still on an ADSL line, then yes the signal is travelling down copper all the way to the exchange and into the MSAN at the exchange or into the equipment of whatever provider has installed LLU.
But if you've switched to VDSL/FTTC, the copper wire has been terminated at the street corner box, which is now the MSAN. And as far as I know, there is no provider running their own equipment here.
>> No. 26544 Anonymous
25th April 2018
Wednesday 11:51 pm
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Fuck, lads.

Strowger switches are fascinating to watch in action.
>> No. 26545 Anonymous
26th April 2018
Thursday 12:54 am
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If you like complicated mechanisms, you might enjoy these:

>> No. 26546 Anonymous
26th April 2018
Thursday 1:20 pm
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Ironically enough I'm an electronic engineer so my ilk have made all these mechanisms useless. But it gives me a pause to think -- have we reached some sort of technological threshold?

By that I mean 70 years ago, I'd say pretty much all technology was understandable by a layman -- you can see how a Strowger switch works, how carburettors in car engines worked, a radio tuner, etc.

Now, most technology is only understood by people who specialise in that field. A farm hand could explain how a carburettor works, but even I couldn't fully explain how a modern EFI works without spending time reading up on it.

I might not be accurately putting into words what I mean here, but it seems to me like at some point in the last couple of decades we've reached a point where pretty much all technology is now out of the realm of understanding of most people.
>> No. 26547 Anonymous
26th April 2018
Thursday 4:00 pm
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>have we reached some sort of technological threshold?

Undoubtedly. We've reached the point that nobody really understands anything. Our technology has advanced through specialisation and the division of labour. We depend totally on trusting other parts of the supply chain, because a human life isn't long enough to learn all this stuff.

Most electronics engineers don't really know how how IC manufacturing works. We might have a slightly hand-wavy overview explanation involving photomasks and doped silicon, but we couldn't make a transistor to save our lives. Many IC manufacturing companies are fabless - they know how to tape out a chip, but they're happy to leave the job of actually etching the wafer and bonding the die to a pure-play foundry. Most software developers don't really understand how hardware works. They might half-remember a few university lectures about registers and ALUs and DRAM, but they couldn't build a basic circuit from discrete logic.

There's nobody on earth who truly understands how their smartphone works. Every component embodies multiple lifetimes worth of expertise, a specialism of a specialism of a specialism.

The capacitor plague is a good example of when this all breaks down. Hundreds of millions of devices failed because second-tier electrolytic capacitor manufacturers didn't understand the electrolyte formula that they had copied from the top-tier Japanese manufacturers. EEs specified cheap caps, without realising that they were sabotaging their own products because of some ultra-specific chemistry related to electrolyte outgassing.
>> No. 26606 Anonymous
10th June 2018
Sunday 2:42 pm
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Well, I finally got hold of one. Unfortunately, the ringer doesn't appear to work. I've not had time to investigate why, but do any of you phonelads who have posted in this thread where I can get schematics, or perhaps why the ringer wouldn't work? The switch appears to be OK.
>> No. 26607 Anonymous
10th June 2018
Sunday 3:36 pm
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Fixed it, 3.3k resistor not fitted where it should have been.
>> No. 26608 Anonymous
10th June 2018
Sunday 9:07 pm
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I've just been pickup up and slamming down the receiver all night. I just want to say things like "IF YOU DON'T HAVE THOSE REPORTS ON MY DESK BY MONDAY MORNING YOU'RE FIRED, YOU HEAR?"


"Tell the police chief we need to get the big guns out on this job."


"Buy gold, no, no, sell gold. Buy silver!"
>> No. 26609 Anonymous
11th June 2018
Monday 1:43 am
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I hope you're turning the dial with a pencil rubber to look extra-elegant.
>> No. 26610 Anonymous
11th June 2018
Monday 7:37 pm
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I think you've got the hang of it.
>> No. 26611 Anonymous
12th June 2018
Tuesday 12:35 am
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You're having more fun then I did when I had a rotary and I was five.
>> No. 26612 Anonymous
12th June 2018
Tuesday 4:29 pm
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Okay so, pissing about aside, want I want to do is:

1. Make the phone show up as a bluetooth headset which can take calls through the receiver;
2. Make the phone ring when the connected bluetooth phone rings;
3. Be able to use pad to make calls - ie pick up the receiver, it opens the phone app, and then sends the numbers you dial in to the phone,and then calls for you.

At my disposal I have a couple of PIC microcontrollers, a Raspberry Pi3, a soldering iron, some various power supplies/components, a fair to middling knowledge of C, C++ and PIC assembly, and a summer of free time.

Can it be done, and do any of you lads know where to start?
>> No. 26613 Anonymous
12th June 2018
Tuesday 5:26 pm
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The hard part is managing the Bluetooth protocol. Pretty much everything else is relatively straightforward. There are a number of single-chip solutions for Bluetooth audio that do most of the heavy lifting for you. A quick browse suggests that the CSR8635 would be a good candidate - you get an 80MHz microcontroller with a useful amount of flash and RAM, a small DSP core, ADC, DAC, lithium battery management and a Bluetooth modem on one chip. Modules and breakout boards are available from the usual suspects for about a fiver. You need proprietary software to flash it, but you don't have to look hard to find a copy.


Using the dial to make calls is a piece of piss - you're just counting pulses. As long as you can write a *while* loop, you'll be fine.

Ringing the bell is mildly inconvenient, because you need to produce ~90v AC. A PWM pin, an H-bridge and a small transformer should do the job.

If that all sounded like Greek to you, then I'd suggest taking on some simpler projects first. This course costs a tenner and covers most of what you'll need to know:

>> No. 26614 Anonymous
12th June 2018
Tuesday 5:47 pm
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I like how they advertise "full lifetime access" as a feature.

What a time to be alive.
>> No. 26615 Anonymous
12th June 2018
Tuesday 6:07 pm
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As I recall, the Pi3 has a Bluetooth module on board - is there any reason you'd suggest the core over that - and can that core or the Pi3 send the dialling commands over bluetooth using the headset standard or would I need to write a 'driver app' of sorts for my phone?
>> No. 26616 Anonymous
12th June 2018
Tuesday 9:40 pm
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It's perfectly doable, you'd just be trading hardware complexity for software complexity. If you're more comfortable working with software than hardware, it's a reasonable choice. An rPI-based solution will have considerably higher power consumption at idle, which might be an issue if you want your project to be battery powered. There's a repo for a software implementation of the Bluetooth Hands Free Protocol at the link below.

>> No. 26651 Anonymous
26th June 2018
Tuesday 7:27 pm
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I've fully restored it now, I think. Replaced the failing carbon granule microphone and added a rectifier.

Only one thing - should you be able your own voice through the receiver?

Turns out a commercial solution for my bluetooth idea does exist, but it does look a bit pricey, especially considering I'll have to modify the RJx jack to the standard BT one: https://www.amazon.co.uk/liGo-Bluewave-Link-Mobile-Hub/dp/B008D2Y1N4/ref=pd_lpo_sbs_121_t_0?_encoding=UTF8&psc=1&refRID=XY82HWSCAM4V9759Q9VN
>> No. 26669 Anonymous
6th July 2018
Friday 9:58 am
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>Only one thing - should you be able your own voice through the receiver?

That was normal from what I remember.
>> No. 26670 Anonymous
10th July 2018
Tuesday 2:38 pm
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Got another one with the intention of selling, ended up lubricating the dial of both of them. Christ, now it's even more satisfying to dial on.

sage for blogging
>> No. 26671 Anonymous
10th July 2018
Tuesday 7:23 pm
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>ended up lubricating the dial of both of them.

>> No. 26672 Anonymous
10th July 2018
Tuesday 9:42 pm
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I mean, this is the closest I will ever get to physical intimacy with another human so yes.

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