| Author |
Message |
eeh
Guest
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 Posted:
Mon Dec 12, 2005 9:35 am Post subject:
Busy Tone Frequency & Pattern? |
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Hi,
I have found in the web that following information about busy tone of
my country:
Tone: Busy
Freq: 480 + 620
Amp: -13
Cadence: 0.5 seconds on, 0.5 seconds off,REPEATED
What is the meaning of "Freq: 480 + 620"? Is it a dual tone frequency?
If yes, could I calculate its existence by just a timer?
I can get rectangular waves in the telephone line using call progress
filter.
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Alan
Guest
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| Posted:
Mon Dec 12, 2005 4:23 pm Post subject:
Re: Busy Tone Frequency & Pattern? |
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On 12 Dec 2005 00:35:53 -0800, "eeh" <eehobbyist@yahoo.com.hk> wrote:
| Quote: | Hi,
I have found in the web that following information about busy tone of
my country:
Tone: Busy
Freq: 480 + 620
Amp: -13
Cadence: 0.5 seconds on, 0.5 seconds off,REPEATED
What is the meaning of "Freq: 480 + 620"? Is it a dual tone frequency?
If yes, could I calculate its existence by just a timer?
I can get rectangular waves in the telephone line using call progress
filter.
|
You may want to look at this site:
http://3amsystems.com/wireline/tone-search.htm
Alan
--
Sell your surplus electronic components at
http://ozcomponents.com
Search or browse for that IC, capacitor,
crystal or other component you need. |
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Joe G (Home)
Guest
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| Posted:
Mon Dec 12, 2005 5:35 pm Post subject:
Re: Busy Tone Frequency & Pattern? |
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There are some tone detector IC's CML micri circuits.
http://www.cmlmicro.com/products/WTelecom/CMX683.htm
http://www.cmlmicro.com/products/WTelecom/CMX673.htm
http://www.cmlmicro.com/products/WTelecom/FX663.htm
"eeh" <eehobbyist@yahoo.com.hk> wrote in message
news:1134376553.170279.252150@g44g2000cwa.googlegroups.com...
| Quote: | Hi,
I have found in the web that following information about busy tone of
my country:
Tone: Busy
Freq: 480 + 620
Amp: -13
Cadence: 0.5 seconds on, 0.5 seconds off,REPEATED
What is the meaning of "Freq: 480 + 620"? Is it a dual tone frequency?
If yes, could I calculate its existence by just a timer?
I can get rectangular waves in the telephone line using call progress
filter.
|
|
|
| Back to top |
|
|
Joe G (Home)
Guest
|
| Posted:
Mon Dec 12, 2005 5:35 pm Post subject:
Re: Busy Tone Frequency & Pattern? |
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PS
-13 is -13dBm in to 600R
480 and 620 are 2 tone frequncies mixed together.
Joe
"eeh" <eehobbyist@yahoo.com.hk> wrote in message
news:1134376553.170279.252150@g44g2000cwa.googlegroups.com...
| Quote: | Hi,
I have found in the web that following information about busy tone of
my country:
Tone: Busy
Freq: 480 + 620
Amp: -13
Cadence: 0.5 seconds on, 0.5 seconds off,REPEATED
What is the meaning of "Freq: 480 + 620"? Is it a dual tone frequency?
If yes, could I calculate its existence by just a timer?
I can get rectangular waves in the telephone line using call progress
filter.
|
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|
| Back to top |
|
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eeh
Guest
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| Posted:
Mon Dec 12, 2005 5:35 pm Post subject:
Re: Busy Tone Frequency & Pattern? |
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If they mix together, how can I analyse the Call Progress signal by MCU
in time domain? I used MT8880 which has a call progress filter. |
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Don Bowey
Guest
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| Posted:
Mon Dec 12, 2005 5:35 pm Post subject:
Re: Busy Tone Frequency & Pattern? |
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On 12/12/05 6:18 AM, in article
1134397136.091129.67260@o13g2000cwo.googlegroups.com, "eeh"
<eehobbyist@yahoo.com.hk> wrote:
| Quote: | If they mix together, how can I analyse the Call Progress signal by MCU
in time domain? I used MT8880 which has a call progress filter.
|
There are two basic types of tones used: Precise and non-precise. The
former is being replaced, over time, by the latter.
The two tones you listed in your original post are "precise tones." They
are simply combined and sent as two tones (not mixed in a non-linear
device).
FYI, often the non-precise tones are used in pairs and one IS modulated by
the other.
Single tone signals predate the precise and non-precise tone usage.
Don |
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