”THE TELEPHONE EXCHANGE” 1982 BRITISH TELECOMMUNICATIONS DOCUMENTARY MONDIAL HOUSE XD47854

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Produced by Ronald Spencer and Pacesetter Productions, this British Telecom promo film explains the evolution of telecommunications in Great Britain, starting from operators manually connecting calls, Almon Brown Strowger’s Strowger switch invention, the Crossbar switch, taken over by the reed relay switch, and lastly the System X digital switching system. The film is a Pacesetter Production by British Telecom, written, produced, and directed by Ronald Spencer. The film is narrated by Michael Dean, composed by Pat Cory, photographed by Alec Sheridan, edited by Peter Pitt, with sound by Dudley Plummer, and animations by Hedley Griffin.
A mother walks her child in a stroller (00:08). She parks the stroller by a phone booth (00:15). Alerting scenes of people using phones (00:22). Various people of all ages in the streets of London are asked about the functionalities of phones (01:10). “The Telephone Exchange” title banner (01:56). Mondial House, a main telecommunications hub in Central London, built in 1972 and demolished in 2006 (02:01). Views of telephone wires built on rooftops and overground in the late 1800s or early 1900s (02:33). A telephone operator manually connecting calls (02:55). Footage of Kansas City, Missouri, during the American Western period in the late 1800s (03:32). Almon Brown Strowger, inventor of the Strowger switch: an electromechanical telephone exchange system (03:43). Scenes of the Old West in Kansas City (03:46). Almon Strowger (04:18). Graphics explaining the functions of the Strowger switch (04:30). A telecommunication building (05:57). Views of the functions of the Strowger switch in use (06:09). Almon Strowger (06:44). Views of engineers in the 1930’s working on the development of the Crossbar switch electrotechnical device (06:51). Views of the Crossbar switch in use (07:04). Graphics explaining the electromagnetic functions of the Crossbar (07:32). Many connected wires (08:03). A telephone operator manually connecting calls (08:18). Views of the functions of the manual switchboards (08:33). Graphics explaining the functions of the manual switchboards (08:57). Rows of switch-systems (09:30). A girl roller-skating and listening to music through her Sony Walkman (09:50). Various electronics, including a calculator and an alarm clock (10:08). Two children play with electronic toys (11:13). Electric chess (11:29). A soccer video game (11:42). A boy is walking (11:47). He checks his Casio digital watch (11:53), and then runs (11:57). A black-and-white photograph of telephone engineers (12:18). A reed relay switch invented in 1936 (12:32). Graphics explaining the functions of the reed relay (12:48). Views of electronic switching systems (ESS) (13:17). Automatic typewriters (13:36). Scenes of people using phones (13:50). A manual switchboard (14:00). The Strowger switch (14:04). The Crossbar switch (14:07). The reed relay (14:09). Graphics explaining the functions of connecting numbers through the exchange systems (14:20). A ticking clock (15:08). An elderly lady sewing (15:15). A circuit attached to a needed eye (15:19). An engineer looking at a silicon chip through a microscope: the System X digital switching system which replaced the reed relay (15:34). A System X telephone exchange system building (16:47). Altering footage of microchip switchers and telephones (17:26). A man waiting at a bus stop received an alert from his pager (18:01). He walks to a nearby phonebooth (18:15). A printer and a fax-machine (18:20). Men watching television using Contravision closed circuit TV (18:34). Mondial House (19:32). A telephone operator manually connecting calls (19:51). Operators working to solve problems with the electronic switching systems and providing personal service (20:01). Views of the functions and wires of electronic switching systems (20:58). A child speaking about the functions of telecommunication (21:18). Informational text overlay (21:28). Credits (21:43).
Mondial House was a main telecommunications hub in central London on the banks of the River Thames. It was known as an international switching centre (ISC). Built in 1978 the building was seen as controversially modern-looking. It was demolished in 2006.
This film is part of the Periscope Film LLC archive, one of the largest historic military, transportation, and aviation stock footage collections in the USA. Entirely film backed, this material is available for licensing in 24p HD, 2k and 4k. For more information visit www.PeriscopeFi...

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11 сен 2024

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Комментарии : 131

@kamakaziozzie3038 6 месяцев назад

“Of course we will always need operators” You gotta love that optimistic enthusiasm

@Alienalloy 6 месяцев назад

The comment I came looking for 😂

@thomasgray6092 6 месяцев назад

I dialled 100, and got through straight away recently! We are with Virgin Media. When I say dialled, I mean it - I was using a 1930's phone!

@iamfinky 6 месяцев назад

"I'm afraid my train's been cancelled again".... gosh, it's like nothing has changed in 40 years 😂

@user-jt5vm3mi1w 6 месяцев назад

shithole

@chrisblay 6 месяцев назад

My Dad worked virtually his entire career for G.P.O. telephones and later BT, from the 1950’s to 1990’s. He was in engineering planning and would have seen so many of these developments over that time. How things have changed.

@axeman3d 6 месяцев назад

I joined BT as System X was being rolled out. Entire floors of strowger kit was made obsolete by a wardrobe size box with a laser warning on the side. It went from multiple engineers per exchange to 1 guy looking after 6 or more. Now it's all software and I can download a free phone system that will run 30,000 phones from a server. Incredible.

@patcom1013 6 месяцев назад

That's SIP you're referring to, right? SIP - Session Initiation Protocol, which enables the Voice Over Internet Protocol (VoIP).

@vink6163 6 месяцев назад

@@patcom1013No SIP is the protocol (a set of rules and procedures), you need software that speaks the protocol, like Asterisk or similar, in order to do something useful with it.

@phillipsmiley5930 6 месяцев назад

Watford 1987 was one of the first to get System X and i was one of the first to get it in less than 3 year all of Watford was on 5 System X switches serving 300,000 lines

@phillipsmiley5930 6 месяцев назад

@@Another-U-Tube-User Ofcom approved power cut fecked for the coming WEF Organised Die hard 4.0 type disaster. Those who remember the power cuts of the 70's and 80's think their landlines will still work like they did then

@naysmith5272 6 месяцев назад

@@phillipsmiley5930yes forgot about communications during a national issue. Will be a man on a bike carrying a message.

@braxtonhickswaxinglyrical3068 6 месяцев назад

I worked in Mondial House the International switching centre shown at both ends of the film. 1981 to 1992. Best working days of my life...

@petergardner5002 6 месяцев назад

I was there too, also at Colombo House shown

@stevewebb1606 6 месяцев назад

I remember it all. I’ve just retired after 53 years in the game. Worked mainly in West London. Strowger, Crossbar, TXE4, System x and AXE10. Then onto mobile phones, 1G to 5G played with it all.

@phillipsmiley5930 6 месяцев назад

When i was young i had fun playing with Stanmore's TXE4 switch, by calling a local number and when it started ringing jab the hook up switch jumping lines, until found one in use, and then pretend to be BT enginners testing the line, and get them to whistle down the phone etc

@mikemainer3009 6 месяцев назад

Spent my career installing, commissioning, and retrofitting DMS switches from the early 1980s to the early 2000s. Lots of travel and lots of good memories.

@bhabbott 6 месяцев назад

Thanks for bringing back some memories. I was a telephone exchange technician in New Zealand from 1976 to 1991. We had British 2000 series Strowger (AKA 'step-by-step') equipment, NEC crossbar and finally NEC NEAX stored program control exchanges (still running today). I also worked on operator's switchboards, and PABXs (electromechanical and microprocessor based, including Plessey and STC systems made in Britain). Good times!

@petermounsey6189 6 месяцев назад

I started as an apprentice with 'Post Office Telecommunications' in 1970, a few years before BT was formed. Had a fabulous time and still relate stories from then. Gave me a good grounding (sic) for when computers arrived.

@5milessep 6 месяцев назад

When I did my training on crossbar in the early eighties, the first subject matter in the course went for two weeks, and that didn’t even get to a point where dial tone was fed back to the customer 😳

@ix-Xafra 6 месяцев назад

Ditto

@karensherlock5015 2 года назад

My great grandfather,an Englishman ,born in Liverpool, invented the dialing system and automatic exchange in ca in early part of 1900s.just thought he should get some credit

@dhm7815 6 месяцев назад

The Infallible Holy Scriptures, aka Wikipedia, say that in 1912 the British General Post Office beta tested a number of competing systems and mentions an unnamed one from Sweden and also Siemens and Lorimer. The beta test sites were Fleetwood, Grimsby, Hereford and Leeds. Strowger's system, tested in Leeds, had more digital switching, less cabling and a faster response time. Wikipedia does not give a clue to a company named Lorimer but I guess your great-grandfather either worked for them or sold his patent to them. While Strowger was favored the competitors were used as well. It was decided to go on the Strowger system in London, bit by bit. The Strowger system was sold to Bell Telephone in 1916. It was called the Director system in England. The Holborn exchange was the first and changed on 12 November 1927 at midnight. The phase in of the Director system went city by city, year after year until Edinburgh in 1950. Liverpool switched over in 1941. That was probably your great-grandfather's system.

@MoeLarrycurly1 6 месяцев назад

👍👍👍

@DukeofDave 6 месяцев назад

Of course he did.

@andrewphillips4508 6 месяцев назад

@@dhm7815my great grand father invented this machine in Edinburgh

@lesbrown5829 6 месяцев назад

Director Area (DA) exchanges were only in London, Birmingham, Edinburgh,Glasgow, Liverpool and Manchester. At first they were given national dialling codes of, respectively, 01, 021, 031, 041, 051 and 061 which apart from the London code was based on alphabetical order. The manner of call routing within DAs was different to how calls were routed in non-DA areas. Strowger equipment was used in both cases.

@steviebboy69 6 месяцев назад

I found it amazing when the narrator said there are 400 million phones and now there are over 8 billion and you can dial the right number and call any one of them. And now we can watch Hi-def video streams and the like over the old phone because of evolving tech.

@MarkPMus 6 месяцев назад

“Hello. Is that the Operator on the line?” “Yes” “We’ll get off, there’s a train coming!” 😂

@kernow9324 6 месяцев назад

Ah, happy memories, Mark. 😀And just dialling 100 in the '70s to ask the time. My mates and I didn't own a watch between us. 18 years later I ended up working in Mondial House, the international exchange shown in the video.

@stevemichael8458 6 месяцев назад

Dad jokes that would mean nothing to kids today :)

@theonlywoody2shoes 6 месяцев назад

I was a TTA (apprentice) joining in 1978. I ended up looking after a 2000 type Strowger exchange before moving on to Manual Board (telephonists) and DQ (directory enquiries) maintenance as I understood electronics and they’d just install the Edgely queuing system (that used TXE4 reed relay modules) at our exchange. I ended up at BT Labs and was there when it was renamed as Adastral Park, ending my career in IT security (Pentester). I’m now retired, but love the “state machine” operation of Strowger systems.

@kernow9324 6 месяцев назад

I can't find any info on the Edgley queuing system, but when I was at Mondial House, customers dialling 155 could be answered by an operator in Mondial House, Wood Street, or Brighton. Different system I guess but revolutionary at the time. Operators in Brighton international exchange thought they should be paid the same as operators in Mondial House just for pretending and saying "London" when an operator overseas called for help. Okay then! 🤣

@theonlywoody2shoes 6 месяцев назад

@kernow9324 Edgely was a call queuing system specifically for Directory Enquiries. The one I looked after was based in (the now demolished) Cardiff ATE in the mid 1980s. It was badly designed, with the control electronics located above the two banks of reed switch modules, so often overheated in summer. I did, later in my career, visit many of the London switches and offices, and certainly visited Mondial in the 2010's.

@FreejackVesa Год назад

Fascinating. It's incredible how more efficient the digital system is compared to electromechanical switching.

@aarond23 6 месяцев назад

The first 10 seconds of music is actually a banger!

@faneuil1 6 месяцев назад

1’44” what is he saying? Sounds like “I haven’t got any clothes on what am I an electrical engineer?”

@eddieafterburner 6 месяцев назад

Based on what he’s wearing-or, not wearing, as the case may be-I’d say that’s accurate. In all seriousness, I love the Brits, but good lord, some of them annunciate as if they have a mouthful of mashed potatoes. In their defense, they probably feel the same way when listening to a Texan.

@berlinocelot 6 месяцев назад

He said 'I aint got a clue I'm a pipe fitter not an electrical engineer.'

@faneuil1 6 месяцев назад

YES! ty! cheers@@berlinocelot

@thebubster0312 6 месяцев назад

I worked for GEC telecommunications afterI I left school at 16 in1974. I was a trainee installer bringing in equipment, fitting out and cable running the racks of Strowger stuff. We were being trained in electronics towards the end of my time in that line of work, spent the rest of my working life in the building trade.

@Consequator 6 месяцев назад

I love these old documentaries.

@asd36f 6 месяцев назад

Nice rotary phone porn in the intro LOL

@richardvoogd705 6 месяцев назад

Half a world away here. I recall when the phone company in my area was preparing to replace the manual switchboard with an automatic system. The first thing I was aware of was a technician installing a dial in the phone (1970?). A couple of years later I had an opportunity to look in the new exchange before it was completed. If memory serves correctly, the part I saw was based on Strowger gear rather than crossbar. Fast forward to the 1980s, I had moved several hundred kilometres away, and noticed that when I rang family the ringing tone had subtly changed, presumably due to a further upgrade. 😮

@pjdee5879 6 месяцев назад

It's amazing how much has changed in 40 years. The past is a different country.

@lucashinch 6 месяцев назад

I like the background music. Nice listening at times.

@sputumtube 6 месяцев назад

Fascinating.

@phillipsmiley5930 6 месяцев назад

All changed in 1987 when System X was introduced

@DrFiero 6 месяцев назад

Today - that woman going into the booth would be charged with child abandonment or something. 🤪

@kernow9324 6 месяцев назад

She probably popped in for a pi55. Public kiosks stank to high heaven sometimes.

@grantc8353 6 месяцев назад

That guy at the start who said it was signals 1 is beep and 2 is beep beep is a clever guy!

@AnthonyHigham6414001080 6 месяцев назад

In the UK in December 2025 the whole lot is going to be switched off and replaced with Voice over Internet Protocol (VoIP) or internet calling. The slight problem is the line will no longer be powered so during a power cut you will lose your telephone connection if you don't have a battery backup system.

@steviebboy69 6 месяцев назад

I have had a VoIP service since around 2016 and its fibre to the node and if the power goes out so does the router, and the node has battery for around 4 Hours from what I have heard. They cut over on the old Copper a few years later, even though with FTTN the last Km or whatever distance is shitty old copper. This is in Australia by the way.

@ianflint4610 6 месяцев назад

Much has already gone. I started working on planning migration to VoIP in the public network in the mid nineties. It seemed an unobtainable target then. But, here we are. Even if you have your own UPS - what are the chances of the batteries (if there are any) in the street cabs maintaining the routers during a power outage? Will BT/VM etc provide line power from battery systems at the local PoP to maintain the outlying infrastructure or properly maintain UPSs at outlying equipment? IDK. That degree of attention costs. You may have a better chance of your local mobile cell site surviving a while, but that is by no means certain. I was responsible for routing telephone traffic including 999 (and implementing 112) in one of the UK largest networks with hundreds of System X and DMS100 switches and connecting to many hundreds of BT units on thousands of routes. The responsibility was enormous. We were handling hundreds of millions of calls per day. Every second downtime on just one unit was 'a problem'. 20 seconds per year was the target. Nothing focussed attention like dealing with and providing massive resilience for Emergency traffic. I expect there will be a day when there is loss of life because of the migration to a 'best efforts' platform that has insufficient attention to services that keep it alive for everyone. It will happen. At least with physical copper in the local loop at the edges were not left stranded when power failed.

@evan010101 6 месяцев назад

True. My rotary dial phone is plugged into a fibre modem now. On a cheap UPS. Do I use that phone.. not really!

@AnthonyHigham6414001080 6 месяцев назад

Well at least you'll be able to dial 999 if your house catches fire during a power cut.@@evan010101

@TeslaTales59 6 месяцев назад

Nice film and great restoration!

@peterkendell5214 6 месяцев назад

I commissioned TXE2 and TXE4 exchanges and coded for System X. Worked for both GEC and STC.

@wickedlee664 2 года назад

Music by Metallica.

@FreejackVesa Год назад

I thought the same thing. Glad I'm not the only one

@edwardburek1717 6 месяцев назад

By the end of the film, they transmogrified in to The Eagles.

@leddielive 6 месяцев назад

Beautiful Red Dwarf quote.

@Ray_of_Light62 6 дней назад

Telephone exchanges still exists, because all telephones and DSL limes must be terminated somewhere. But they are now changed into big server rooms, and in the coming years they will shrink further as the PSTN Lines are phased out in favour of IP telephony. Distinction between phone and data lines will disappear, and the phone will become just one of the computer terminals on the data line. With the phasing out of copper pairs in the future, DSL modulation (broadband) will no longer be necessary, as the fiber optic can carry data directly (baseband). In the end, the phone socket of the times past will become a fibre-optic Ethernet port, capable of transferring any kind of data encapsulated in successive layers of the data transmission protocols. If there is one negative aspect with the new, fully digital approach to Comms, is that the old analogue system operated with a current loop, therefore carrying its own power; the new standard require a local source of electricity in order to operate. In other words, an IP phone doesn't work during a power outage...

@harryjones5260 6 месяцев назад

a version of dire straits tunnel of love at the end

@MeaHeaR 6 месяцев назад

Yes itt did soundé Liké thé Outro, esp thé Piano untt Drumbs

@sensorytriggered5606 6 месяцев назад

Came here to say this!

@stephenB-yq9kw 6 месяцев назад

I used pay phones as a teen to make hoax calls

@kernow9324 6 месяцев назад

I think you got away with it! 😀

@stevemichael8458 6 месяцев назад

And now I no longer have a landline. Things change quickly :)

@cedley1969 6 месяцев назад

The exchanges are far different now, empty buildings with a skeleton crew watching the computers doing the work.

@1969gawa 6 месяцев назад

3:08 Did she play a teacher in Grange Hill?

@danielbarnard8069 6 месяцев назад

I’ve got no idea I’m a Pipe Fitter Cracking. 😂

@BritinSchleswig 6 месяцев назад

Amazing to think that with those clever electronic switches and the dedicated lasses in the exchange Nixon got a perfect connection to the Moon back in 1969.

@retiredammo4617 2 года назад

I rent getting the snow cone machine for. Christmas. Boy I made a lot of snow cones.

@yakacm Год назад

Wake up grandad, that was the film before.

@craxd1 6 месяцев назад

At the end, when speaking of developments, you'll notice a bunch of magnetic wire running through round objects held in place by metal brackets. I believe this was an experiment in early magnetic memory, which would store either a one or zero (magnetized and demagnetized toroid) as memory.

@CableWrestler 6 месяцев назад

That's core memory and had been used from at least the 1960s

@1harryrobert 6 месяцев назад

It's a cyclic store on a TXE4 exchange

@Blueeyedboy77 4 месяца назад

Incredible how when you watch these types of films, ‘energy’ isn’t ever mentioned as a factor. It’s as though the entire 20th century was just regarded by everyone at the time as an age of abundance and energy consumption was just not ever a consideration for anyone.

@Fanakapan222 5 месяцев назад

Ah the Glory Days ? In 82 there'd still have been many in the management structure who'd started out during the wartime years as linesmen. Then came the rebranding from Post Office Telephones to British Telecom, privatisation, and the monumental rise in share prices as Iain Vallence assured us that BT was going to take over the world. Shares now struggle to make £1.50, so much for that strategic vision ? Today its Open Reach, and saddled with maintaining the lines that were largely put up when the nations telephony was publicly owned. Quite a journey from Tommy Flowers at Dollis Hill, to today's Shadow of what the GPO once was. Maybe it mirrors the decline of Britain as a whole ? :)

@bluejedi723 6 месяцев назад

why are the comments a year old but the video was uploaded only 10 minutes ago?

@thomasgoodwin2648 6 месяцев назад

Used comments? Just a thought.

@dhm7815 6 месяцев назад

Uploaded by an operator directed call instead of dialing?

@PeriscopeFilm 6 месяцев назад

@bluejedi723 apparently, sometimes people find our unlisted videos while they are waiting to be published!

@bluejedi723 6 месяцев назад

@@PeriscopeFilm it took a year to publish some videos? Okie dokie

@PeriscopeFilm 6 месяцев назад

Yep! You see, we publish two videos per day, and there's roughly a 10-month backlog. Before the pandemic it was actually a much longer backlog, up to two years.@@bluejedi723

@dieseldragon6756 6 месяцев назад

That quote at 20:11! 🤣 Somebody clearly didn't see the forcing-in of consumer self-service and the coming of AI, did they? ☎🤖🙃 Also: I might be younger than this video, but still old enough to recognise the bus company shown at 01:36 - Back in the days you could manage Camberley to London on under two quid! That livery may be long gone (Stagecoach bought the company years back) but that actual coach is probably *still* sat at the back of Halimote Road depot _somewhere_ ... 😉

@lumpyfishgravy 6 месяцев назад

This 80s video is so 1970s.

@activelow9297 6 месяцев назад

1982 was still the 70's.

@eddyaudio 6 месяцев назад

Old Hat now we have phone in our pockets these days Technology has moved at a breaking neck speed.

@phoneticau 6 месяцев назад

I worked on Ericsson ARF ARE AXE PSTN between 1880 to 2005 and VoIP between 2005 to 2020 retired seen it all

@MJ-iv1es 6 месяцев назад

So your career lasted 140 years? You must have a huge pension!

@ix-Xafra 6 месяцев назад

I worked on all those and ARK as well StepXStep and did battery replacement, too. Melted a few tools working on live gear, lol...

@carlwaring 6 месяцев назад

Do you really need to out your own time-stamps /id over the films? Very annoying. (I don't mean the web URL watermark.)

@PeriscopeFilm 3 месяца назад

Here's the issue: Tens of thousands of films similar to this one have been lost forever -- destroyed -- and many others are at risk. Our company preserves these precious bits of history one film at a time. How do we afford to do that? By selling them as stock footage to documentary filmmakers and broadcasters. If we did not have a counter, we could not afford to post films like these online, and no films would be preserved. It's that simple. So we ask you to bear with the watermark and timecodes. In the past we tried many different systems including placing our timer at the bottom corner of our videos. What happened? Unscrupulous RU-vid users downloaded our vids, blew them up so the timer was not visible, and re-posted them as their own content! We had to use content control to have the videos removed and shut down these channels. It's hard enough work preserving these films and posting them, without having to spend precious time dealing with policing thievery -- and not what we devoted ourselves to do. Love our channel and want to support what we do? You can help us save and post more orphaned films! Support us on Patreon: www.patreon.com/PeriscopeFilm Even a really tiny contribution can make a difference.

@phoneticau 6 месяцев назад

Pentaconta Crossbar

@jagmarc 6 месяцев назад

ah the time when a telephone call was simply an incredibly clear voice shaped current sent between phones, and not as today your voice quantized into a pattern for instructing a text to speech voice impersonating gsm robot at the other end by lossy compression cut up into sections into time slots inserted into frames etc etc

@flamencoprof 6 месяцев назад

"text to speech voice impersonating gsm robot " Not even internet telephony does that today. Where did you get that idea?

@jagmarc 6 месяцев назад

Don't you mean How did we all end up with GSM. Year this film was released there was Dial A Disc phone number. Garbled mess try that over GSM @@flamencoprof

@jagmarc 6 месяцев назад

@@flamencoprof Don't you mean How did we all end up with GSM. Year this film made there was Dial A Disc direct number. A completely garbled mess try that over GSM. Because the robot impersonating the caller can only model a human vocal tract not a full orchestra.

@jagmarc 6 месяцев назад

For a classical music OB the BBC leased a prime and redundant phone line that had the full bandwidth. GSM call bandwidth is a joke @@flamencoprof

@jagmarc 6 месяцев назад

Each time I repost a followup with more info it dissappears Y T C E N S O R S H I P

@LilOGold 6 месяцев назад

🎉

@andrewsedgwick7299 6 месяцев назад

2,52 epileptics look away

@eddieafterburner 6 месяцев назад

3:32 As much as the BBC was having a good time here with their stereotyping of Yanks, they were unwittingly closer to the truth than they realized: a land of miserable cities where undertakers are the biggest business in town due to frequent gunfights, all punctuated by the occasional spark of invention and ingenuity for business purposes, albeit necessitated by corruption.

@MrCobo04 6 месяцев назад

Now no more switches. Fibre routed end to end via SIP

@MrAzztech 5 месяцев назад

crossbar

@keithammleter3824 6 месяцев назад

A fair bit of nonsense is given in this film. Strowger did NOT devise a practical switch. He merely thought up the stepping/rotating contact basic concept and explained it to a family member, who decided to set up a company and comercialise the idea. They employed a competent electrical engineer to devise the switch, something the unskilled Strowger could never do. The idea that Strowger was worried that the phone company was connecting potential customers to the opposition undertaker is an old urban myth. At the time, Kansas was a large city with dozens of undertakers, but very few people had a telephone. Business communication was conducted by messenger boys/runners - an early form of courier service. Or if you wanted something, you hailed a horse-drawn cab or walked to the business premises. The narrator claimed multiple times that electronics works at the speed of light. The sort of silicon chips available when this film was made worked at best at a small fraction of the speed of light, and cables carried signals at only a fraction, sometimes a very small fraction, of the speed of light.

@CableWrestler 6 месяцев назад

Electrons travel at the speed of light.

@keithammleter3824 6 месяцев назад

@@CableWrestler No, they most certainly DO NOT, as any competent electronics engineer or technician knows.. In a vacuum, electrons can be accelerated by an electric field. Since they have mass, Einstein's E = MC^2 applies - the closer you get them to the speed of light, the greater their effective mass becomes. An electron velocity of the speed of light cannot be attained as then their effective mass would be infinite, requiring an infinite force to achieve. The highest practical speeds are obtained in vacuum devices such as X-ray tubes, where extraordinary voltages are required, hundreds of kilovolts, resulting in speeds a small fraction of the speed of light. In ordinary metallic conductors, where the voltages are small (a few millivolts/inch at most), electron speeds are tiny - a tiny fraction of an inch per second. In semiconductors such as silicon, electron velocity is typically about 1000 times faster, this is still a very tiny tiny fraction of the speed of light. The advent of radio electron tubes (what the British call valves), where electrons are accelerated in a vacuum, and strike a metallic plate called the anode is how electron mass was measured for the first time. Due to their mass, they have kinetic energy, and this energy is converted to heat in the anode, which can be accurately measured. The quantity of electrons is precisely known from the current, and their acceleration known from the anode voltage.

@simonch5140 6 месяцев назад

Back in the 70s when I was an apprentice at Post Office Telephones, the only thing that went at the speed of light in my exchange was the rush for the door at 5pm 😂

@1harryrobert 6 месяцев назад

@@simonch5140 We finished at 4pm

@simonch5140 6 месяцев назад

@@1harryrobert back in my day it was 8am to 5pm.

@karensherlock5015 2 года назад

Name of inventor, Robert h. Leather