Touch-tone (DTMF)
The pairs of tones a telephone keypad makes. On radio they send numbers and commands.
ModeTouch-tone
FamilyTone signaling
Audio example1.2 s
What does it sound like?
Plate 70Tone signaling
Short beeps that sound exactly like pressing phone buttons.
0 Hz1,0002,0003,000 Hz
1.2-second example. Recording: Freesound recording freesound-phone-dial-dtmf-466832 (CC0).
Field marksTwo tones at once16 possible tone pairsTones between 697 and 1,633 Hz
Who uses it?
Repeater owners controlling equipment, radio users dialing phone patches or identifying themselves, some business systems.
Where and when can I hear it?
Mostly on VHF/UHF FM channels, in short bursts.
What do the decoded parts mean?
- Digits: The keys pressed: 0-9, *, # and sometimes A-D. Their meaning depends on the system.
Easily confused with
- APRS (position and messaging): packet is a continuous warble, not paired tones