At home, I still use a W48 [0], I bought somewhere in the mid-90s on a flea market.
Just have to change the carbon capsule microphone every twenty years or so.
In doubt, one can change to a simple transistor circuit microphone.
My router has a phone jack that provides enough voltage to the bell.
Works like a charm.
My parents still have two working rotary phones on their landline. And not one of those fancy, newfangled plastic ones, theirs are metal that hurt my fingers. They are hard wired into the wall as they are from before RJ11 connectors.
They got FIOS a while back. The tech that showed up was gobsmacked that the phones still worked after the install.
Before RJ11 connectors, phones in the USA were not hardwired, at least not where I was from. There was a 4-prong, large plastic beige connector. When RJ11 became popular, I remember converters from this old 4-prong to the new RJ11 “modular jack” as it was colloquially called.
It definitely depended on where you were in the US. For some comparison, our home in Quincy, Illinois (built in 1895) did not have a No. 283 four pin setup like you linked; instead, the original phones were hardwired into the walls and the copper. Conversely, my grandparents’ home in Morton, IL had the 283 plugs.
Before reading the article I was sure you installed a SIP client on Raspberry Pi and wired the speaker/mic to the headset so she could actually make calls with it.
Still awesome.
I have a rotary phone hooked up to a VOIP box that doesn't support pulse dialing.
There's a guy in Australia who makes little in-line adapters that translate the pulses into touch tones. It's about the size of a U.S. wall jack, line-powered, and works very well.
I've had it for something like ten years, so I'm afraid I don't have any contact information. But if he's making them, someone else might be doing the same.
In short I installed a Raspberry Pi Zero into the case of the phone. I considered using an esp32 but the Raspberry Pi is alot more straightforward because I can simply run Linux and code in Python. On the esp32 I could write the code in C++ but it would take longer, or use micropython for esp32 but that no doubt would be harder than the Raspberry Pi.
I found several YouTube videos and also some web ages that described how to connect the rotary dialler to the GPIO pins on the Raspberry Pi, and I found some example code that captured the number dialled on the dialler.
To connect the speaker in the handset it was a little more involved. First I had to work out which wires coming out of the handset cable were the speaker wires - there were four wires coming out, two yellow and two pink. I screwed off the speaker portion of the handset and pulled out the speaker, revealing two yellow wires. The Raspberry Pi zero does not have an audio out port. So I bought the cheapest possible USB audio card for about $20 https://www.centrecom.com.au/shintaro-usb-audio-adaptor-with... and also bought a 3.5MM audio cable which I cut and stripped back the two wires and connected them to the two yellow wires from the handset speaker.
I knew that the hangup/pickup switch must allow/deny a flow of electricity, so I got out my cheap multimeter and started randomly touching parts of the phones circuit board in two places, and lifting and pressing the hangup switch. Eventually I found two points which resulted in electricity flowing or stopping when the switch went up and down, so I knew this must be right connection points, which I then connected to two of the GPIO pins on the Raspberry Pi.
I removed the wire which connected the phone to the plain on telephone line and instead put a USB power cable there.
At this point I had worked out how all the various bits and pieces worked so I wrote a Python program to tie it all together.
When the phone handset was lifted, I played a dial tone audio file. I had about 60 audio files, which I uploaded to the Linux file system. I gave each audio file a number from 100.mp3 to 160.mp3 so when a phone number was dialled, I searched a list of the files, and if the dialled number matched an mp3 filename then I played that file.
I had to remove the bells from the phone unfortunately to fit the computer in.
One of the disappointing things is that it is not possible to make the phone ring because the ringer requires a much higher voltage than can be generated by a small computer. You could probably fake this by installing a small speaker and just playing the sound of a phone ringing.
> One of the disappointing things is that it is not possible to make the phone ring because the ringer requires a much higher voltage than can be generated by a small computer.
Voltage can be stepped up using a transformer, no problem. It's that you need 20~25Hz AC and a certain amount of current (see "ringer equivalent" calculations). Either way, you're probably right to skip it for this project :)
> because the ringer requires a much higher voltage than can be generated by a small computer.
I mean that’s not quite true. A magicjack which is basically an ATA is about the size of the Pi Zero and produces ring power. A REN is on the order of 10 mA which at 90V can be generated by a very small (like smaller than a dime) switcher.
Indeed the quickest and easiest way to “modernize” an old phone is probably to stuff the guts of a readily available analog telephone adapter and interface it to a Pi, or a Wi-Fi adapter, etc.
For the problem of converting pulses to tones, some time ago I made a small circuit that generates the DTMF tones directly inside the phone. It's basically an interface between the rotary dial and the phone line, based on a simple 8-bit PIC microcontroller powered from the phone line (actually coming from an ATA). The idea is to publish it as open source hardware as soon as I find enough time to document it... Downside is that you have to solder it (SMD components) and put it inside the phone...
Normal phone lines will supply upwards of 100ma, but since you only need to ring one ringer, you can do with less, you can also tune the ringer to make it more sensitive.
Thank you for sharing your project. I recently took the analog phone down from my grandmother's house, and I've been asking people to send me their voicemails from her over the years for a similar purpose.
She recently suffered a stroke that's left her confused and unable to engage, and the abruptness of what was a much slower transition into dementia has been upsetting to the family. I'm hoping being able to pick up her receiver, dial her number, and listen to one of the many loving messages she's left us throughout the years will help. She's also deaf now, otherwise it would have been designed like yours.
Eventually I'll deploy it as a PBX so others can call in, but I haven't had much time to test.
> So I bought the cheapest possible USB audio card for about $20
That looks like a generic Chinese USB audio card and they are sold for much less where I live (~$1.5). Aliexpress has a ton of them around that price level.
I grew up on rotary phones in the 80s. Though I havent touched one in over 30 years, I still remember the distinctive feel of the rotary dial, it certainly had its own character but it was quite tedious to call another number, especially a number with high digits. In the 90s they were removed from my area but they were still touch dials translated to pulses. It felt a lot more modern but it would still take longer to dial high digits. I remember having a repertoire of 40-50 phone numbers that I had commited to memory. I still remember a few which I still use now in passwords:)
I remember when I heard the rationale¹ for the assignments of area codes in North America: Populated areas with a high subscriber count would get the lowest codes to reduce the number of pulses required. Hence 212 for New York, 213 for Los Angeles, and 312 for Chicago.
My next thought was self-pity. My area had just been assigned a new code: 909. The absolute worst code possible². 28 pulses required for us bumpkins while only 6 were needed for the cool people in the city. :)
[1] There's a good Underunderstood episode on this. Apparently it's not exactly certain this was the rationale. No memo exists detailing it, but it matches up pretty well with how they were initially assigned. (https://underunderstood.com/podcast/episode/area-code-conspi...)
[2] Well, I guess 900 is actually worse, but that's not a geographical area code.
I wonder if they came up with some of the plan to backfit the political considerations. NJ getting 201 and DC getting 202 fits with the numbering scheme, in that codes assigned to entire states (or district as is the case with DC) had a middle "0", whereas states with more than one code got numbers with a middle "1".
Was New Jersey the most populous state to only receive one code?
> Only very rarely are area codes tinkered with in this manner. The only other one I can think of is 321 for the area around Cape Canaveral.
That's awesome. It would have been a crime to pass that opportunity up.
I always thought it was particularly cruel that all emergency services (police, fire, ambulance) in my country were reached by dialing 000. It doesn't doesn't make much difference now, but imagine waiting for that rotary dial to spin all the way back around while your house is going up in flames around you...
In British Columbia, 112 was once the prefix for making long-distance calls. That changed in 1985 to bring us into conformity with the rest of North America.
Edit: also, you could call for free on rotary pay phones by tapping out the number on the "hangup" switch.
In the late 80s I was messing with a rotary phone hook switch and dialed 117 accidentally, which was the proctor test set. It was an automated phone testing platform, and it would let you test things like the coin receiver and touchtone tones, among other things.
I never had the coin sound maker, but I did have a small transcription digital recorder years later that could trick the proctor test set into thinking a nickel had been inserted.
I don't remember all the other tests, hopefully there's a webpage somewhere about it.
Back then you never needed to dial your own area code unless you traveled far away and called home. At least not where I lived. So it’s no skin off your back that it took the better part of three seconds to dial your area code at ten pulses per second.
Back then you never needed to dial your own area code unless you traveled far away and called home.
Back when there were lots and lots of small local telephone companies within a single area code, where I lived you didn't have to even dial all seven numbers.
As long as you were calling within the same phone company, you only needed the last five digits. So calling the neighbor across the street was just 2-3342. But calling someone you knew who was a mile away in a different phone company, you had to do the whole 867-5309. There were some people you knew who lived across the border in another state, and for most of them you had to dial all 11 digits.
But some of the small phone companies operated on both sides of the state line, so you could still dial people with 9-9845, even though they were in a different area code in a different state.
It was also billed as a local call, which made the BBS I ran the main e-mail exchange point between those two area codes for the store-and-forward BBS network I belonged to.
I was mostly joking about the envy of lower codes. DTMF had long replaced pulse dialing when the 909 NPA was created. Still supported, but even my grandparents had touch-tone phones.
I recall as a kid thinking it seemed ridiculous for there to be a specific monthly surcharge to allow TouchTone dialing. (I also learned that you could drop the service and TouchTone dialing would still work, so it really felt like they were just taking money from people too ill-informed to make a good decision.)
It was ridiculous. I learned from 2600 that apparently telcos needed to upgrade their switches (or some other thing) just to be able to distinguish who had touch tone phone service from rotary.
You could use this to your advantage as well, for instance in a phone booth or with a coin op phone in a bar by simply breaking the circuit with the hook in the rhythm of the dialing pulses. Free calls!
In Italy emergency numbers were usually 112 or 113, it was common enough that telephones were prevented from dialing other numbers by putting a lock on #3, but emergency could still be called, see:
The gist of it was putting a Pi inside a b/w CRT, soldering the GPIO to the tuner and that way you could change the channels. I even put fake static on some of them.
The software ended up horrible as I ran out of time.. but it worked great!
That's pretty great. Well done, I'm sure your mom is going to be thrilled. I'm always amazed at what people are able to build when they set their minds to it
I remember when my grandparents’ phone company did some sort of upgrade in the 90s that forced them to use a touch tone phone. They returned the rotary phone they had been renting from the telephone company since sometime in the 50s.
Wow, in a museum, makes me feel old, I was trained in how to adjust them in my first career, end of the 70's. Saw the last 'step by step' exchange decommissioned a few years later, I was working in the 'cross bar' exchange next door. The first 'electronic exchange' was built across town - it used solid state switching.
It is, I used to love the noise of it, the chunk, chunk as a call was connected. The switches were so big and noisy compared to now, just realised its one of those things thats disappeared into the past.
Initially they went the way of the reed relay, then the 4066 happened and after that VLSI. I remember the difference walking around in the large (building size) exchanges in the 80's and 90's where a whole floor of gear would be replaced by something the size of a couple of refrigerators.
I have a pulse princess phone on the kitchen wall that is still working and is attached to the original Motorola VT-1005 ATA that Vontage provided when they first started in 1995. I have had this unit in continuous use and it receives pulse dialing as well as provides a very robust ring voltage/current. The web interface for this ATA does not allow configuration settings and the unit attempts to retrieve an FTP configuration file on boot from the provider.
Someone on dslreports.com years ago reverse engenered and worked out the format of the config. file and created a config file creator program as well as a serial script to hook to its TTL serial port to change the address of the TFTP server. I now have it providing two analog lines from voip.ms that have a strong enough REN to power several old analog phones with real bells in the house.
It even allows you to pulse dial class five codes like disable call waiting and call voice mail. EX. 1,1,6,9 = *69 if touch tone dialing.
I think these are used as botnet command and control information. The bots randomly surf the web till they find a sequence of words or numbers that match some preprogrammed checksum or signature, and use some of the numbers as instructions of what to do.
The controller's of the botnet then spam the encoded instructions on comment sections all over the web.
Do you have any photos of the inside, and how you replaced the parts? I think some additional technical details and photos may help to get traction here.
This is such a thoughtful idea--I'm sure she really enjoyed it. I'll bet there are some people who would enjoy being able to buy a "modern" rotary phone for purely aesthetic reasons.
I've looked many times! I always enjoyed using rotary phones, and I'd love to see a modern version that supports today's features like caller ID. I've seen a few, but they're often "luxury" models with exorbitant prices.
I recently got a Western Electric 302 on craigslist and am planning to hook my house up on FreePBX/Asterisk, as I live in a 3 story townhome and it would be nice to have the bottom and top floor calling on real phones. Just yesterday I confirmed that it could ring and function normally with a Rotatone EXT and Linsys PAP2T. Alongside that I want to play around with the idea of it as an interface to a speech-to-text application.
It's a great idea! At home I use a rotary Northern Electric 500 and a french S63 with DTMF keypad, both connected on the same VoIP line with an old ATA box (Grandstream HT502) compatible with pulse dialing. Because of differences between the two phones, I must plug them on two separate ports in the ATA. It can be configured to append automatically a phone prefix when dialing 7 numbers.
My mum's 70th birthday is coming up and I love the idea of giving her a gift like this. However, she is probably not the kind of person who will have fond memories of rotary dial phones so I'd like to implement it in another way. Does anyone have any other suggestions of some piece of technology that she can input random numbers into and receive pre-recorded messages?
I'm not sure why you specifically want to make it [input random number] -> [output message], but if the [input random number] is not the important part...
You could buy a portable digital voice recorder and pass it around the family to record their messages. This may not be as much "fun" because most probably won't have the random playback factor.
To get that, you could record the messages and load them up on an MP3 player. That will enable shuffle mode. If doing some sort of custom hardware project was an important part of the idea you could wire up a permanent speaker and maybe do a 3D printed enclosure. You could take it a step further and eliminate the MP3 player and do it on a Pi with some hardware buttons.
If your mum is or was into vinyl records, there are places that will custom press vinyl.
I think I have settled on this: an "FM radio". She listens almost exclusively to Classic FM so doesn't really have much reason to touch the dial. But I think she would get a real kick out of adjusting the channel to "tune in" to her friends and family.
Some other ideas in case people are also looking for other ideas:
- A "safe" dial (when she bought her house they found an old antique safe under the stairs which became a source of some mystery until it was cracked open (it was empty))
- A numeric keypad (my mum used to use this a lot when she worked as a translator and had to memorise the unicode for all the French characters)
- Just a simple box with a big rotary dial knob on the front - can't really think of a good story for this though.
The answer is, in most cases so long as you have a traditional landline, they have to do something special to turn it off. No one wants to put in a new switch and find out 10% of their customers cant use their existing phones, so all the carrier grade stuff supports it. VoIP is another issue, you have to hunt a bit harder to find a VoIP ATA with support for it, but they're out there.
I have and sometimes use a 1935 Western Electric phone and it's associated "subscriber set" with my Google Voice account. The phone itself is completely unaltered, as is the subscriber set. Just a plug for a typical phone jack.
I once had a teenager say it was "complicated" to use; dial 9 for and outside line and the number.
Is there really a law that makes it illegal to display an antique phone that isn’t connected to a phone line? Is a box of old cell phones now to be considered a weapon of mass destruction?
> Is there really a law that makes it illegal to display an antique phone
> that isn’t connected to a phone line?
No. However, there are laws that devices which purport to provide telephone service must be able to connect to emergency services.
> Is a box of old cell phones now to be considered a weapon of mass destruction?
No. There is no expectation that a device that is disconnected or inoperable will continue to function. That said, a _modified_ device that continues to function would likely still be considered under such laws.
The world is now filled with not too old cell phones that are operable but will no longer function as 3g and below networks are decommissioned - it was similar when AMPS was decommissioned. The expectation that any old phone turning on modified or not will get service is just not realistic.
> There is no expectation that a device that is disconnected or inoperable will continue to function
If the guts of a phone are replaced then I’d argue that’s no more or less operable then an old cell phone.
I think laws in the context of ensuring that device manufacturers provide reliable 911 service is sensible (ie maybe it should be enforced against Google) - but as some nanny legislation because someone might confuse a display piece is a bit silly in my book. (And think of the elderly as insinuated by the GP is weak and insulting - having dealt with demented parents - whether the phone was connected was of no issue - simply identifying a phone was a bigger problem… meanwhile old people aren’t automatically idiots).
It’s also absurd to think that someone lacking the situational awareness to identify a non-working phone also has the faculties to read some warning sticker. This is something that comes from a corporate legal department not something that normal people would think to do.
That's why operators are pretty careful about decommissioning old gear, they monitor the usage and ensure that the stuff is no longer in use when they finally switch it off, and then usually by reducing the density bit by bit rather than by switching off a whole region all at once.
In a panic I would almost certainly waste some seconds on it if I wasn't familiar with the situation. So I can totally see how this might cause trouble. It's not always the owner or someone who lives there that will attempt to call 911 it could easily be a caretaker, a cleaner or someone else visiting. Also, to be greeted with a bunch of happy birthday messages while trying to reach 911 has a macabre kind of feeling attached to it.
One quick fix would be to be that if someone dials 911 the phone immediately responds with 'this device is incapable of reaching 911, please use another phone'.
Why does he hate his mum so much?
Rotary phone for an 80yo is like having a guillotine for fingers.
I am still in my 40s and I DO NOT WANT to use a rotary phone ever again.
People claiming that the voltage is an issue have little idea about modern power conversion. It’s doesn’t take much juice to drive the ringer - less than a watt.
Any basic ATA will easily drive a ringer.. ever seen a MagicJack? - it’s a complete USB telephone adapter and barely larger than a thumb drive. They aren’t greatly hackable - but something like a Grandstream HT801 can be opened and the board put inside and you basically have an entire telephone interface right there. They even support pulse dialing.
You can't drive the ringer unfortunately because it requires a much higher voltage to drive it, something like 48 volts I seem to recall.
Two options for getting around that.....
You could install a speaker into the phone and play a recording of a phone ringing.
You could install a little electric motor with a lopsided head on the axel and position it in between the ringer arms and spin it at the correct hertz and it would ring the bells.
About 90 volts. (48v is the nominal on-hook voltage; Wikipedia tells me that the official ring voltage spec is 60 to 105 volts RMS at 20 HZ.) This page has a circuit for generating the appropriate signal given a 12 volt input: http://techlib.com/electronics/telephone.html (plus a small extra circuit for using a lower voltage for control signals).
I used to install T1s back when they were the "fast" way to get online. The vast majority of installations used HDSL to modulate the T1 onto the local loops.
HDSL powered the remote card from the one in the central office, using (IIRC) 130VDC.
One time I was at a customer prem troubleshooting an installation. The customer's phone vendor was out there with me as we were hunting for the right cable pairs in the terminal. I was getting ready to call another tech back at the CO to put a tone generator on the line when the phone system vendor told me to just run my fingers across the terminals until I got a shock.
I thought he was joking. He wasn't. He looked at me like I was a weenie and went ahead and did it himself. Dragged his fingers down the line until I saw him twitch. "Binding posts 47 and 48, right there"
I had accidentally shocked myself probably dozens of times, but never as a troubleshooting technique!
A fun coincidence: someone posted about a similar memory just this morning[1]!
> Removing insulation from a live phone wire with my teeth (I had decided to put an extension in my room without asking for help...) was one of mine, that definitely made me more careful. Went just fine until I closed the circuit with my tongue by accident just as someone called. Not pleasant.
It’s less than one watt of power - a tiny boost converter and a mosfet is all you need - no transformer or relay necessary - it takes less than a square inch of board space.
I didn't realize it was that low - I thought it was a few amps. And even a single amp multiplied by 80 volts is far beyond what I would pump through typical hobby mosfets used with e.g. an Arduino or Raspberry Pi.
By yeah, if it's just a watt, that's going to be on the order of tens of milliamps at 80 volts. It probably wouldn't even need a heatsink.
I had a device to do just this for old phones. I was always needing this feature for stage productions set in the past; they almost always have a phone that rings at some point and it's much more authentic to have the phone ring than to use the speaker system of the theatre.
Eh. What? Many phone companies in Europe had an option to keep your ancient landline phone. It was just connected to a box that understands rotary dialing and acts as a cellphone. But this generation of subscribers mostly dead now.
The phone acts as a familiar medium for new content. You don’t call people with this phone, instead it’s used to hear pre-recorded messages from her friends.
Sounds little creepy. I would not want such a gift. When my mother's rotary phone was changed to touch phone, she started to whine it hurts her fingers. I found her rubber covered screw drive handle to poke buttons. This made her happy.
Depends on the cognitive level of the said granny, but hearing ghost voices in a dead phone is either scary or creepy. I seriously doubt she can appreciate the effort and technological achievement at any level.
Nor does she have any fond memories of old crappy phones. In the olden times phone calls were so expensive that everytime the phone ringed it was something serious and mostly bad.
"In the olden times"... POTS service in most places wasn't just used for serious/bad events. Perhaps in 3rd world environments.
The OP was making a present for their grandmother's 80th birthday, in 2021, so their grandmother was born in 1940 or later. Someone in their 80s these days is unlikely to be so cognitively impaired as to be worried by phone calls.
They're more likely to be facetiming with grandchildren from their iPads/iPhones.
In Australia, POTS service was universal and the call costs for local calls was untimed and minimal (perhaps $0.10/call). Timed calls were for longer distances in Australia (STD) or for international (IDD).
Unless you're talking about up until the very early 80s, when long distance / international calls required operators.
In my parents area of the US, Bell had a monthly charge for 'touch-tone' dialing. My father always held out, but eventually they sent him a voucher for replacing their rotary phones. I've only seen rotary-to-mobile adapters as a hipster accoutrement.
They are in this age range and now prefer to call people on their iPad.
Not sure what you've said right there but OPs phone wasn't made to be a functional phone. Hes turned it into a mp3 player for his mother's birthday messages. Also I'd disagree on the mostly dead part. Anyone over 30
likely remembers rotary phones.
I think you’re totally missing the point of this post. But in many countries including the US, POTS twisted pair landlines are still readily available. And I am surprised that at least some parts of Europe don’t still offer it - isn’t ADSL still super common there?
At home, I still use a W48 [0], I bought somewhere in the mid-90s on a flea market. Just have to change the carbon capsule microphone every twenty years or so. In doubt, one can change to a simple transistor circuit microphone. My router has a phone jack that provides enough voltage to the bell. Works like a charm.
[0] https://en.wikipedia.org/wiki/W48_(telephone)