DTMF Selective Calling

DTMF selective calling lets you "ring" a specific radio on a shared channel, similar to making a phone call. Instead of everyone on the channel hearing your transmission immediately, only the radio programmed with the matching DTMF code will alert its operator — other radios stay silent until the recipient responds.

How it works

Your radio sends a short burst of DTMF tones (the same tones a telephone keypad makes) at the beginning of your transmission. On the receiving end, radios programmed to decode that specific tone sequence will sound an alert — a ring, beep, or flashing display — while all other radios on the channel ignore it. The recipient then keys up to respond, and you have a conversation.

DTMF selective calling uses sequences of digits (typically 3 to 5 digits) as "call IDs." Each radio in your group gets a unique ID. When you want to call a specific person, you enter their ID before transmitting.

Setting it up

1. Assign call IDs: give each radio in your group a unique numeric code (e.g., Radio A = 123, Radio B = 456). Keep codes short — 3 digits is common
2. Program your radio's "self ID": this is the code your radio listens for. When it detects this code, it alerts you
3. Program the other party's ID: store the codes for radios you want to call, usually in a contact list or speed-dial memory
4. Enable DTMF decode: make sure the decode/ANI feature is turned on in your radio's menu. If it's off, your radio won't respond to incoming selective calls

Practical uses

• Group coordination: on a busy channel, call one specific person without disturbing everyone else
• Convoy communication: call the lead or tail vehicle directly while others monitor silently
• Event staffing: reach a specific team member at a festival, race, or volunteer event
• Family groups: let kids' radios alert only when mom or dad is calling

Limitations

Selective calling is not a private channel — it only controls whether the receiving radio alerts. Anyone monitoring the frequency with squelch open will still hear your voice after the DTMF tones. It also doesn't work through all repeaters, as some repeaters may strip or retransmit DTMF tones inconsistently.

Both radios must support DTMF encode and decode, and the codes must match. If you're setting this up for a group, standardize on a code list and make sure everyone's radios are compatible. For a reference list of common DTMF codes and how different radios implement them, see our DTMF Call IDs guide.