Telephone dialing

When you go off-hook, the A Relay pulls in. Any short interruption of that current will pulse the A Relay (as long as it isn't long enough to drop out the B Relay).

There are some phones that have a tone/pulse switch. Everything should be backwards-compatible.

Something isn't working to spec, either at your end or theirs. An old modem and a dialer app might narrow this down

--if you're the type who never throws anything away (and never bought any WinModems).

On a sunny day (Wed, 18 May 2011 21:57:00 -0700) it happened "Paul Hovnanian P.E." wrote in :

It does here, Netherlands, but for many places you dial you will soon get one of those speaking computers "dial '1' for , dial '9' to speak to a real human being" . That part wont work, needs a tone.

To my surprise, the menu system of my local surgery was perfectly happy with the pulse dialling from my 1981 rotary dial phone when I called them just last week.

Cheers,

Robert

And in the UK. I guess it depends on your local exchange. "123" is a phone based time service and dead easy to pulse dial by hand. "111" gets urgent healthcare and "999" emergency services ambulance/fire/police which is somewhat harder.

That used to be a real menace when calling the US with a pulse dial phone from the UK. Aftermarket in tone pads to hold to mouthpiece.

Regards, Martin Brown

On a sunny day (Thu, 19 May 2011 11:40:10 +0100) it happened Robert Rudolf wrote in :

I tried calling the utility company last month, "unrecognised selection, try again". Then I remembered I had accidently moved the pulse-tone dial switch (because I forgot what it was for), so put it the other way and it worked.

Still works in San Francisco.

John

ff.

Sure, I've got an old rotary phone out in the shop. Great for when the power drops out as all the other phones have AC power plugs.

George H.

In many places of the US pulse dialing still works. It's been years that I've tried but it did work out here (east of Sacramento). We have this phone in our kitchen, fully functional:

The sound from it really sounds like in very old movie, cool. The ringer is LOUD, makes some people think a fire alarm has gone off. Of course the crank is disconnected.

Those old things are rather practical. You must stand up, meaning less back pain and no unnecessarily long chats. Has built-in continuous memory in the shape of a "micro desk", notepad (a real one), pencil with fully integrated rubber eraser. Message deletion features are also provided, by means of a little waste bucket below. Has integrated anger management to deal with rude calls: Tear sheet off pad, crumple, throw into a corner with gusto ... there, feels better already :-)

ff.

I will overgeneralize and say that all US POTS lines that go to a "real" central office still accept pulse dialing. Even, say, BRI's in private homes often provide pulse dialing functionality to connected phones.

OTOH few modern PBX's will accept pulse dialing. (I know of some 70's era PBX's that only did touch tone so modern extends back at least 40 years). I'm guessing you were using a PBX of some kind.

Tim.

Tim Sh>I'm guessing you were using a PBX of some kind.

ASSuMEing that the handset is to spec: In the central office / PBX A Relay -- 100ms pulses (80 - 120ms probably OK) B Relay -- 225ms of off-hook after a pulse train will ratchet to *next digit* C Relay -- 375ms of on-hook breaks the connection[1]

If the handset is mechanical and the dial speed is correct[2], I would also say there's a non-Strowger-compliant PBX in the loop.

If the handset stores numbers electronically and dials them from that, there are some more variables there. . . [1] I said "B Relay" previously when I should have said "C Relay".

#5 ESS still does, I don't think it can even be disabled by the software, it is handled entirely by firmware in the register/senders.

I can imagine some RTs or other switches may well drop the pulse dialing feature.

Jon

That's amazing, I'm pretty sure this will NOT work on almost any modern US switch, even on a local-local circuit. It would take something like a crossbar switch for that to work here, where you had a real copper connection between local calling and called parties.

Jon

Believe me, I was equally amazed when the system actually reacted correctly.

Who knows, maybe there is still an ancient exchange working here. But even then, their PBX has to accept pulse dialling, too.

Cheers,

Robert

Most "modern" switches are 20+ years old. Newer ones are built on 20+ year old functional ("'POTS") designs.

Im not aware of any switch on the market (what's left of it- next gen is IP based al the way through) that doesn't accept pulse dialing.

H.

Some exchanges have a pulse to DTMF converter to allow the use of obsolete equipment like alarm systems and charge extra for the service. Kind of like when DTMF became availible in my home town. Their first DTMF to pulse converter would only handle 100 phone lines.

Most SLI (Subscriber Line Interfaces) are perfectly happy reading pulses, no matter what the switch. You just might have one that has had the feature turned off in sofware...

Charlie

I have FIOS for my phone service and the ONT accepts pulse dialing just fine. Art

Still works here in NY, I bet they grandfathered it in for safety reasons.

Cheers

This was to a real CO. Ex GTE/Verizon, now Frontier.

I'm guessing that my old lineman's phone may be getting a bit gummed up, throwing off the timing and getting my call canceled.

Anyone have a link to pulse dialing specs and tolerances. I may throw this thing on my oh-silly-scope to see what's up.