.DTMF Decoder / Encoder

 
DTMF Decoder is a very easy to use program to decode DTMF dial tones found on telephone lines with touch tone phones.
DTMF Decoder is also used for receiving data transmissions over the air in amateur radio frequency bands.
 

The following are the frequencies used for the DTMF (dual-tone, multi-frequency) system, which is also referred to as tone dialling. The signal is encoded as a pair of sinusoidal (sine wave) tones from the table below which are mixed with each other. DTMF is used by most PSTN (public switched telephone networks) systems for number dialling, and is also used for voice-response systems such as telephone banking and sometimes over private radio networks to provide signalling and transferring of small amounts of data.
 
 

Table of DTMF frequencies (CCITT)

Symbol
Tone B [Hz]
1209
1336
1477
1633
Tone  A  [Hz]
697
1
2
3
A
770
4
5
6
B
852
7
8
9
C
941
*
0
#
D

 
“Live” tone signals are fed from telephone line or radio into soundcard of computer.  Either line- or microphone input jack is used. It is highly recommended to ensure galvanic decoupling between PC and telephone line or radio receiver.  DTMF Decoder output is clear text consisting of the symbols shown in table above. An exact log is displayed; when, which number was dialled. This log is automatically stored into a log file for later exploration.


System requirements:
Windows 95 / 98 / Me / NT4 / 2000 / XP / Win 7 (see instructions below)
Processor Pentium or higher
Processor clock 1Ghz
256 MB RAM or more
5 MB free disk space
Soundcard

Windows 7 specific instructions:
Locate DTMF Decoder at it's Program folder location  for example "C:\Programs\HamRadioSoftware\......DTMFdecoder.exe" 
Right click on the DTMFdecoder.exe file to access the properties
In the properties / compatibility table one must set: XP Service pack2
 

Technology:
Digital Signal Processing (DSP)
Finest 5th order Gaussian Bandfilters with adjustable bandwith.
Excellent Signal to Noise Ratio (SNR)
 
 

More Info:
Download and view the DTMF Decoder Help File
 
 

Download: Free Full Version

Download VB RunTimeLib here!

Win 7: Do not install VB6 Runtime Libary! It is already included in Win7


 
Sorry, the DTMF Decoder is no longer for sale!

 
Download the DTMF Encoder (Dial Tone Generator), it's Free! ( no cost at all )


 
 
 

Contact:
Send your problems, suggestions, and questions to my e-mail: dtmfSPAM@polar-electric.com (remove the letters "SPAM")
 

Related Links:
Decoder and Controller Products (Hardware)

http://www.icircuits.com/

Thanks for visiting!