EEVblog

[@law-ofohms7815]

When I was in high school we had on of these for the students to use. It was just plugged into the wall like a regular phone. So I came along with a spare normal phone handset and plugged it in to make free calls.... lol. good ol days....

[@hugomartel8552]

here you can short two wire together and it disable the pay function.... LOL

[@Westimation]

Hi Dave. I was an instructor for NZ Telecom and trained local area techos on installation & maintanence of Agifon (Landis and Gyr) small coin phones. L&G Coin validator works using 2 coils. A frequency was feed into the first coil and the phase shift mesured in the second coil. A different frequency was feed in & the results of both phase shifts (digitized) compared with a ROM map. If my aging memory serves me right they used about 1000 coins of each domination used to make map. Graham Dredge

[@looncraz]

The phone is designed, IIRC, to not accept coins without a dial tone. Carrier voltage only gets you so far.

[@fuzzytech3846]

looncraz i see from your avatar that some one has played American McGee's Alice. nice

[@therealjammit]

@EEVblog The two coils that sense the coins works in this manner. Each coil is the inductive part of their own oscillator. When a coin passes past them, the coin pulls the frequency. If each coil is resonant at different frequencies, you can determine which type of coin went past. Pull the frequency too high or too low means a slug was inserted.

[@ryallmackcowling]

I got one of these with the keys on ebay for $50, I'd love to see a way to use VoIP with it as the copper phone lines are going soon.

[@adrianlongley-preston5190]

We're in... but not like FLynn? D:

[@brazenhawkrt7691]

Well, the phrase "In like Flynn" means to gain access to something quickly and with little trouble. As he needed to drill it out I would say he was not in like Flynn that time

[@adrianlongley-preston5190]

+adam polcyn I've learned a thing!

[@herbie5263]

Who,s Flynn?

[@jessiedover6561]

I really love these old school teardowns, Thumbs up

[@flyguille]

the telephone didn't accept money because the microswitch pointing that money box isn't inserted.

[@Polite_Cat]

Love teardown tuesdays! They're my favorite!

[@adamanderson8484]

Press [Follow On] button, as you release it then press the hangup levers, this needs to be done as fast as possible. After about 100 attempts you will get the timing right. When right you can have the phone in the hung up position but still have dial tone, then you can call for free. haha...

[@AgentOffice]

what's follow on mean

[@adamanderson8484]

There is a button on the phone called "follow on"

[@jw5031]

What does the "Follow On" button do? In the US we dont have that button on any phone. Is it the same as "Return Coin" in case you want your money back and you havent made a call?

[@rich1051414]

If you have leftover money in there, enough for a second call, press the button then hang up and you get a second call.

[@gregistopal]

That board layout is beautiful

[@sheriff0017]

The coin validator pots might be set at the factory. They may have made one coin validator for the entire world, and set it according to each country and gunked it at the factory.

[@definitionofis]

At 22:12 I am reminded of long ago when high school shop students, at my school, pounded a spiral of bare copper wire to use in the school front door pay phone. The police visited and they stopped doing it. They realized it was serious theft. I was impressed with how fast they could make one and that it was not distinguished and rejected by the coin detector.

[@OsmosisHD]

I've tried calling 911 in Europe just out of curiosity what would happen Turns out it automatically switches the 911 into our local emergency services 112 Bet AUS does the same trick? calling 911 automatic transfer to 000

[@joshlad2878]

Osmosis yes it does

[@opiniondiscarded6650]

That's pretty neat to know for us Yanks who travel

[@Centar1964]

+Osmosis I thought most of Europe was 999...Didn't know Aus is 000...NorthAmerica used 911 instead of 3 of the same digit to help eliminate "pocket" dialing" the emerg number.

[@OsmosisHD]

Craig Diamond Most common is 112 in the EU, 999 is also used (UK and BE i thought not sure tho) and 061 in some other EU countries

[@mediocre-motorcycle-modifi6818]

+Craig Diamond That's not right when 911 was chosen as a number people didn't have mobile phones. On an old phone with a dialing disc 9 was the highest voltage and the strongest signal so the UK choose 999 as a number. The US choose 911 as it was quicker to dial yet still had a high voltage for the first digit.

[@themcc1879]

lockpick me ass, it's dremel time. BEST QUOTE EVAR!

[@rikvdmark]

Blast from the past, love it!

[@Inertia888]

I was expecting not much more than a change-counter/ but wow~ what a nice surprise, this is a beautiful piece of engineering!

[@EEVblog]

Usually I don't have an "opening". It's just "Hi" and straight into it.

[@MinnoW12]

Look forward to watching a video on the coin sensors! Freq, wave shape & return inductance etc. !

[@FyberOptic]

It's always interesting to see something that was commonplace in another country but that I've never seen before. Whenever someone says "pay phone" I always imagine the iconic American vertical wall-mounted version.

[@barrygiblett5823]

Love the coil validator, would be a good investment for my fridge, beers $1.00, coke $0.50 would work well... keep up the good work...

[@bobbailey8246]

Beer for a dollar! I'll be round later after work :-) Is there a BBQ as well?

[@seanzappulla71]

I used to see quite a few of these on Fraser Island here in Queensland Australia.

[@timtim2500]

I don't know if I will make your day or will ruin it... But i'm NOT an electronic engineer... and I enjoy your videos soooo much :) (I guess I'm not the only one here like this!)...

[@nanquan491]

Probably didn't accept the coins because it needs to detect an active phone line... otherwise it would make no sense for it to accept money if it "knows" it can't provide service.

[@randacnam7321]

The free floating keypad and LCD are for purposes of ease of alignment with the holes in the front case.

[@robbo5life]

I remember in a hospital in woop woop they had that phone there only a few years ago

[@James_Bowie]

[From the manual] Electronic Coin Validation Circuit (ECVC) The Gold Phone can validate a maximum of 4 coins designated 1D, 2D, 3D and 4D which corresponds to the 10 cent, 20 cent, 50 cent and one dollar coins. The ECVC performs the validation of coins on the basis of thickness (T), material (M) and diameter (D) parameters. When a coin is inserted, the four high frequency coils each produce an AC signal which is proportional to one of the coin parameters. These AC outputs are then amplified and converted to DC signals and fed to a differential amplifier for temperature compensation. The compensated output is fed to a peak hold circuit. The signals are then converted from analog to digital signals to be fed into the microprocessor which compares the input data with prespecified values for T, M and D stored in the microprocessor ROM to judge whether a coin will be accepted or rejected. If a coin is accepted, a signal is sent to the SM magnet allowing the coin to pass to the storage channel. The value of the accepted coin is sent to the coin collection microprocessor for later use.

[@tHaH4x0r]

Teardown tuesday is the best show on the eevblog!

[@TubesValves]

Nice phone, one of my favorites. It needed pulses from the exchange to operate correctly and also a good ground(earth). The follow on button meant that if you had put enough money in you could disconnect the call and make another by pushing the "follow on" get dial tone and not have the hassle of hanging up and putting your coins back in

[@Keith_Ward]

I realize this vid is quite old, but love the old phone stuff Dave! Was another vid ever made of the coin validator?

[@thekaiser4333]

I heard that the streets of Australia are paved with gold, but also the phones??!! Incredible!

[@johncornell13]

great to watch, need to do one on the old A and B button phone!!!

[@SuperNathan90]

these are absolutely stunning when ringing.

[@stargazer7644]

In the States, the -48V is only there when the device is on hook. When you come off hook it drops to about 9V DC.

[@quesocat42069]

We have dollar coins here in the us but the only machines that really accept them seem to be postage stamp machines (which will also give change in dollar coins where applicable) and some newer soda machines. They have also redesigned almost every one of our bills except for the $1 bill presumably so they won't have to change every bill validator in the country.

[@0xbenedikt]

Many coin validators work by measuring the coins fall speed. Then it could compare and check if its valid and what value the coin was. This way the validator could be used in many countries.

[@peterstone1447]

for the rear lock (service) you need a M00002 Key. the Tariff board as spot for 6 diodes. first 3 in the line are 10c, 20c and 30c first charge, second line is for extra charge that depend on time of call. so if it had a diode in first and third spot, means 40c , only one diode in the middle is 20c

[@ashtreylil1]

surprised its vandal proof with the cord, some pay phones used to have metal cords

[@1965peteredward]

These were intended for "protected" locations (shops etc) so they werent designed to be very vandal resistant.

[@rocketman221projects]

I would like to see a more detailed video on how the coin validator works.

[@therealandycook]

Here in Canada we use -48vdc to -52vdc depending on the card, and typically about -32ma depending on loop length and card.

[@silvermica]

The sticker on the bottom of the gold phone listed Anritsu. I worked for Anritsu! Spectrum analyzers! (We were Wiltron)

[@Marmalade000000]

You're so funny!!!! That bit in the beginning was hilarious! I remember using those pay phones as a kid and sometimes the lines used to be long!! I remember using a phone card too... Aah, the days before you had your own phone LOL

[@kd1s]

If it worked anything like the 1D2 style phones here in the U.S. everything was controlled by the central office - and that big coil is likely a coin relay.And the way they did it was they'd send 130VDC down the line - either +/- for coin accept, -/+ for return. That is until the early 1990's when we got what were called COCOT style phones. All the brains were inside the phone. I have an old 1D2 in my collection.

[@cho03]

I've got one of these with a white metal stand. Just missing the cash tray and panel 😢

[@zhayward3190]

Its Actually a Telecom CT4 Gold phone before they changed there name to telstra just so you know ;)

[@StrapMerf]

Not the only one who recognised the upsidedown shoes

[@danieluchwal3515]

Cool I was going to say that looked like the Telecom symbol

[@1965peteredward]

....and the CT4 was for Coin Telephone number 4....

[@sleary7878]

Never seen you resort to the crowbar method before :)

[@JesseRay89]

Ha 23 and I still remember them, even with the old Telecom logo. I think my town was slow on the upgrade.

[@groverasylum9626]

US viewer here. I remember seeing one of these in a 2600 mag! so cool to see a teardown! Where is the send button!? ;) And why does Dave think we all talk like hillbilly's ?

[@Browningate]

That's the craziest payphone I've ever seen!

[@sonick808]

even the fasteners in that thing are top notch. That phone is damn well built. good luck finding something like THAT these days

[@michael.kavanagh]

Could the coin rejects be something to do with the money tray not being present? The micro-switch?

[@tejas57]

you need one of those big blue rotary dial ones now dave

[@seanzappulla71]

I wonder if they would work on the NBN phone line.

[@rfvtgbzhn]

In many European countries they still have telephone booths, however almost nobody uses them anymore...

[@TomaszWota]

rfvtgbzhn Yep. It's interesting how new booths were built not so long ago, a few years. Mobile telecommunication really took off, eh?

[@mausball]

Altium dig at the beginning may have been the very best part. I just finished telling my reseller exactly why I want to go back to v9, with bug fixes.

[@tbdau]

Also have one sitting on my desk at work as part of our "tech museum"

[@WaimateTV]

Have you ever teared down a philips catscan mri machine? Be interested in seeing that

[@thomasfowler2964]

I wouldn't mind betting that the dual coil system is to make sure the coin is actually passing down into the machine, rather than being "fished out" like I'd see people trying when I was a kid. Ie: drilling a small hole in a 20c piece and tying some fine fishing line through it so you could dip it in and pull it out, essentially getting free calls. I have never seen it work, so obviously there's something stopping it.

[@Bodragon]

...but that's not for today... I don't think you heard me! But that's not for today! Haha! (At least I watch your vblogs all the way through). Keep up the good work, my good man. xxx

[@jessiedover6561]

most of them used the 600-series plug got to love the 80's

[@AnthonyDFHogan]

If the keypad looks slightly familiar, the "Nitsuko" is a giveaway - they're the ones who made the old chunky Commander office PABX systems.

[@Tutoelectro1]

I thought it was Randy calling :) I really miss him!!

[@dalriada842]

Has the composition of Australian coins changed since the phone was last in service? UK coins have not only gotten smaller, but the metal composition of the lower denomination coins has been debased over the years.

[@toxanbi]

First few minutes I was expecting Doug Ford will be presented by Dave Jones as a creator of this device as well as in previous videos :)

[@4E047RHH]

Back when local calls were 20 cents!

[@realitygroup6857]

Geez There's still one in the local shopping centre here in perth.

[@marksc111]

'The' local shopping centre? Like there's only the one? Perth is even more of a backwater than I thought! 😁

[@mubd1234]

I bought one of these phones off eBay for $30 (bargain). The way the coin system works is that the phone stores the value of the coins in memory and begins deducting the value of the coins as metering pulses (which increase in frequency depending on the call value) are received by the phone from the exchange, so every 30 seconds the balance would go down by a defined value. My gold phone accepts coins on a normal non-metered line, so I think there must be a fault in the phone in this video.

[@SuperNathan90]

do you see that first solenoid switch in the coin shute thingy well the coins have to go in that slot that goes behind it to be read. because there is actually a third coin reader there.

[@goldenboy5500]

there are very few pay phones left here and the ones that are here it's $1.50 for the first 3 minute than $1.25 for each additional minute

[@greytimberwolf68]

Here in the states it is 45 for the line voltage and 90 for the ringer.

[@TonyP9279]

greytimberwolf68 Ideally, it's 48 volts (or -48V referenced to ground), but after miles of twisted pair, you'll usually measure a lower voltage. I work in telecom so I have -48 burned into my brain!

[@greytimberwolf68]

good to know, thank you. i only used testers at votech and that is what they were set for.

[@EEVblog]

In this case there is no EPROM. It's an ancient 4bit mask ROM micro that almost no programmer would read, and it's got no serial/debug interface anyway, so really nothing interesting to be seen/hacked.

[@SuperNathan90]

and it has to trigger that also, so yeah if you tape that down and put the coins in the coin slot it should go straight through and tally on the coin display.

[@DanielVidz]

31:50 actually if you dial 911 in Aus it will connect you to the emergency services.. I guess for those to ignorant not to learn our ems phone numbers.

[@Darwinpasta]

I suspect that it wouldn't accept coins because it didn't think the con box was installed... that microswitch you noticed underneath was disconnected, right?

[@isashach]

I don't know about Aussie coins, however the local ones here have a tendency to oxidize, requiring users to scratch them against the machine. Virtually every snacks, drinks, ticket, etc machines here have their paint stripped of thanks to the scratch marks just above the coin slot.

[@The_Unknown_Wog]

they still have one at blacktown workers club

[@oniruddhoalam2039]

There is 48 v dc in the phone line to power the landline phones.

[@shmehfleh3115]

Hey, how many Dollarydoos does it cost to make a phone call in Oz? :D

[@youtubkeeper]

900 dollarydoos!

[@Speaker_Network]

Shmeh Fleh 50 cents

[@puma4646don]

.......I'm sorry to tell you, but it really does. Quote from wiki: "Due to special configuration in their firmware, some 3G or GSM mobile phones sold in Australia will redirect other emergency numbers, such as 9-1-1 and 9-9-9, to Triple Zero (000). These calls are sent out by the handset as an emergency flag to the network and as such are treated in the same way as a call to Triple Zero (000)." Most phones sold in the past 5 years do this, payphones also redirect in the same manor.

[@sallowsandy]

Hehe motion sickness from spinning phone, but his tear down gave me a warm feeling.

[@MLeoDaalder]

Wait, what if you need to place an international call from an internal office phone? Dial 0 to get out of the building, and then add two additional 00s to dail international, right? In Europe/Netherlands if you place any call with 112 in the number it call the emergency services.

[@900Yugo]

Australia's international dialing code is 0011.

[@tymitunie]

Dave..."the interesting thing" as you called is used today also ie. the ending of ISDN line (client side) is powered from directly from the telephone line (digital telephone signal is around ~96V). Ofc today you can power up any wire telephone on analog line without connecting it in to mains power. (analog around ~46V-5xV) its standard not the "interesting thing"

[@hunter00047]

You need a phone line with dial tone, once call is connected the line polarity is reversed at the exchange.

[@0xbenedikt]

+isashach Here in germany some machines have got metal plates on them which are ment (and labeled) to let people rub their coins on them, even if our coins doesn't oxide. So these machines haven't their color rubbed off.

[@BitZorg]

According to Wikipedia that's actually a special feature implemented in firmware on GSM phones, presumably so if a tourist needs emergency services he'll be able to access them easily. P.S.: It also works for 999 which is used in some countries.

[@MegaWayneD]

I remember in the 80's TV show Sons And Daughters they recoloured them red and referred to them as "Red phones" presumably to avoid product placement advertising problems.

[@marksc111]

No-in Victoria we had loads of red public phones. They were extremely common in the early 1980s, especially in shopping centres. They all had a sign behind them that read "Got something to say? Ring on the Red phone here!" (Don't ask me why this useless fact with the exact wording has stuck in my brain after all these years… it just has 😀)

[@wickedxe]

actually (after a shitload of research) it was waiting for a metering signal. when you make a call of one of these phones, the metering signal tells the phone which tarif to charge for the call, like if it's an STD or local call or a free call, and the phone won't work as a payphone without the metering sig (they usually have an "owner mode" on the key switch so it can be used like a non payphone

[@therealandycook]

Even with the digits 911 - it still happens fairly regularly. Typically caused by static on fax/dialup/data lines where the subscriber never uses it for voice.

[@petermichaelgreen]

I blive it's a way to place another call using the credit from the coins you have inserted but not "spent" yet.

[@frollard]

Might be different, our north American pay phones would hold the money until it detected the line connected - something about the off hook at the other end of the line told the phone, 'okay, release this money into the cash box'. If the other end never picked up, the money was released to the reject bin.

[@nekomasteryoutube3232]

Almost all vending machines and pay phones here in Canada reject money if there isn't power or in the case of phones, theres no signal/dial tone. I guess its just the nice thing to do and it'll jam up if theres no power to operate the coin mech if it takes them

[@Falcrist]

I was thinking that maybe the EEPROM lost it's data during the extended period without power. When was the unit taken out of service?

[@Lachlant1984]

You're referring to this as the Telstra Gold Phone, but of course I'm sure you remember that Telstra was known as Telecom back when this phone was new, indeed I see the old Telecom T logo on the top panel there.

[@PauloConstantino167]

Can you do a teardown of a 56K modem please ?

[@dash8brj]

Another thing you should have mentioned for our US friends is if you need to make a 000 call, you don't have to put any money into the payphone first. Of course that's if you can find a payphone in the first place. They are getting rarer and rarer as mobile phones have become so popular. On a mobile phone (cell phone) here you dial 112 for the emergency services. It too is a free call; and you dont even need a valid sim card in the mobile.

[@maderpl1]

It is really interesting how coin validator works. Maybe author should make a video about it? About the coin validator tests: 1. No tone 2. No coin tray 3. No power suplied while test.

[@archerbob6847]

is the coin validator in this phone the same as you would see in a pinball machine that accepts tokens?

Brilliant!

[@boxvic]

It probably won't accept coins because it recognizes it doesn't actually have a connection to the POTS network. In North America (and I assume most other countries) pay phones evolved to use pulses to connect to the central server to report coin values. The phone's coin mechanism reported the value of all coins inserted, and thus allowed you to keep inserting coins and gaining time as you were talking. Without that connection no coin would be accepted to prevent the phone stealing your money.

[@JordyValentine]

So that's why they always spat coins back at me, I was putting them through before the current could build fully