Author Topic: Searching the best way to provide North American dial tone to my phones  (Read 3576 times)

Offline Haf

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This problem occurs if you're outside the US and want to have correct North American dial tone, busy tone etc for US phones.
At the moment I use an Auerswald 4020 PBX to handle all my phones, but it provides only German tones. But I want US tones for my phones. So I'm thinking of the best way to do so. I don't have the space for Chuck Richards tone plant fur sure, even if that would supply old dial tone! So what to do? I was thinking of using a Panasonic PBX after my Auerswald (guess it provides correct tones) but there are difficulties. 50hz here, not 60. There would be a possibility with transforming 110 Volts 60hz to 220 Volts 50hz but that is expensive and mybe not the smothest way. Anyone here with a better idea? If there is a possibility in getting the old US dial tone would be great but "standart" modern North American dial tone etc will do.

Haf
Telephone:
0049-030-55474418
001-415-449-4743

Offline twocvbloke

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Re: Searching the best way to provide North American dial tone to my phones
« Reply #1 on: January 27, 2018, 06:47:30 PM »
I've used Audacity in the past to generate tones (dial tone, ringing tones, busy tones, etc.), but haven't a clue how you'd go about injecting them into an electronic PABX without poking about inside the thing with an oscilloscope to find where the tones come from and break into the circuitry physically to replace them with an externally generated set of tones...

Offline Haf

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Re: Searching the best way to provide North American dial tone to my phones
« Reply #2 on: January 27, 2018, 07:04:06 PM »
 twocvbloke,

generating the tone is not the problem, even if the old US dial tone seems to be a bit more complicated. Bill Guerts can tell you more about I believe. But you're right, how to insert the tones to my Auerswald, if? I even wrote to the manufacturer, but no answer. I guess the manufacturer should have the possibility to upload those tones to the ram (or whatever, no expert in this).
But there must be another, more simple way. at least I hope so. But as you're here, let me confirm something. I read that there is a Panasonic UK version with 220 volts and 50hz. Does this unit has US or UK tones? and are they maybe changeable?

Haf
« Last Edit: January 27, 2018, 07:14:40 PM by Haf »
Telephone:
0049-030-55474418
001-415-449-4743

Offline twocvbloke

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Re: Searching the best way to provide North American dial tone to my phones
« Reply #3 on: January 27, 2018, 07:16:14 PM »
The UK Panasonics have the same tone generated within the units, the only difference is the ringing cadences, external calls are the .4 on .2 off .4 on 2 off type ring, and the internal calls are the 2 on 4 off, the voltage & frequency have no bearing on what the unit generates... :)

As for whether they can be changed, I don't know that either, I've had a look around inside both my 308 and 616 and couldn't really identify what does what so don't know where the tones are generated...

Offline Haf

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Re: Searching the best way to provide North American dial tone to my phones
« Reply #4 on: January 28, 2018, 06:14:16 AM »
The UK Panasonics have the same tone generated within the units,

And is it the UK or the US tone? If they where sold in the UK I suppose equipped with UK tone.

Haf
Telephone:
0049-030-55474418
001-415-449-4743

Offline twocvbloke

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Re: Searching the best way to provide North American dial tone to my phones
« Reply #5 on: January 28, 2018, 07:26:32 AM »
It's a tone unique to the Panasonic units, presumably sounding different to differentiate between an internal and external call, I don't know what frequencies they use to generate the tone, but it's nothing like the UK or US tone...

Offline Haf

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Re: Searching the best way to provide North American dial tone to my phones
« Reply #6 on: January 28, 2018, 07:47:28 AM »
Oh, well...then this is not the solution. Whould have been to easy, wouldn't it? The Auerswald PBX I use simulates the German dial tone. Maybe someone has another idea for my problem. I still believe it can be done somehow.

I did some research in the past, this is the tone what I am referring to as old dial tone:

http://elmercat.org/phone/chuck/



Haf
« Last Edit: January 28, 2018, 07:57:18 AM by Haf »
Telephone:
0049-030-55474418
001-415-449-4743

Offline twocvbloke

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Re: Searching the best way to provide North American dial tone to my phones
« Reply #7 on: January 28, 2018, 08:42:38 AM »
Yeah, using modern means to generate tones that were often electromechanical in nature isn't easy, after all, it's hard to compete with the real thing:

https://www.youtube.com/watch?v=VzIXvO6RahQ

With Audacity, I can make a tone that kind of sounds like the dialtone there, by generating a 50Hz sawtooth wave (some exchanges also used 33Hz), but doesn't sound as good as the real thing, even piped through a telephone... :-\

Offline Haf

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Re: Searching the best way to provide North American dial tone to my phones
« Reply #8 on: January 28, 2018, 08:52:27 AM »
yeah...even if it looks way complicated doing this with electromechanical devices (and believe me, I do not understand a single of those diagrams) it should be more or less easy be done with a computer. In the article is one to me familiar name: "Bill Guerts built it that way and he says it sounds fine."

The maybe hardest thing is...how to provide it to my phones? I can support POTS, ISDN and VoIP here with one or another of my devices. So whatever can provide old or at least North American modern tones to my phones would be fine.
Raiding the CO is no option btw ;)
Telephone:
0049-030-55474418
001-415-449-4743

Offline twocvbloke

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Re: Searching the best way to provide North American dial tone to my phones
« Reply #9 on: January 28, 2018, 09:14:06 AM »
There is one option for getting the tones to your phones, assembling your own switching exchange...  ;D

Offline Haf

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Re: Searching the best way to provide North American dial tone to my phones
« Reply #10 on: January 28, 2018, 09:18:45 AM »
I was really considering that option, yes. Already took a short look on ebay about equipment offered. But, as I wrote, matter of space, money and knowledge. Must be a more easy way...at least I hope so :)

Haf
Telephone:
0049-030-55474418
001-415-449-4743

Offline twocvbloke

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Re: Searching the best way to provide North American dial tone to my phones
« Reply #11 on: January 28, 2018, 09:52:28 AM »
I think the easiest way was as I'd mentioned earlier, probing the inside of a PABX to find where the tone comes from and interrupting the circuit to inject an external (MP3 player?) audio source with the appropriate dialtone on there, which sounds a lot easier than it probably is...

Offline dsk

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Re: Searching the best way to provide North American dial tone to my phones
« Reply #12 on: January 28, 2018, 12:10:03 PM »
Haf, If you look at this document: https://goo.gl/nFY2dT you may see that also the UK dial tone has been used in the US.
Not sure about the Difference between US  and US Panasonic exchanges, but they should not relay on mains frequency since battery backup is an option.  By that reason you should be able to run a US exchange an a 50Hz supply of a suitable voltage.

I may try to get a you a recording of the UK Panasonic dial tone.

dsk

Offline dsk

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Re: Searching the best way to provide North American dial tone to my phones
« Reply #13 on: January 28, 2018, 01:29:01 PM »
The dial tone (UK Panasonic KX-T 616 10) looks like this.
To get a sound: enclosed zip files are allowed.  or listen here: https://instaud.io/1I3e
Picture from: https://academo.org/demos/spectrum-analyzer/


My guess is approx 350+440 Hz Maybe, a little under as 340+420 Hz
The 350+440 has been used in UK and USA according to the pdf in my over.


dsk
« Last Edit: January 28, 2018, 01:46:57 PM by dsk »

Offline twocvbloke

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Re: Searching the best way to provide North American dial tone to my phones
« Reply #14 on: January 28, 2018, 03:23:35 PM »
Looking at that file in audacity, it looks to be around about 350+450Hz, doesn't sound right when generating tones in another Audacity window though...