Learn your radio
Set this before you fly
446.09375 MHz · 114.8 Hz
Dolomites — Italy
The official free-flight safety channel in the Dolomites, grown from the Rete Radio Montana “8-16” convention. Monitor it; call on it in an emergency.
No official Swiss equivalent exists — agree a channel with your group.
446.00625 MHz
First contact
The de-facto calling channel by community practice. Call here, then move to your group's channel.
The six things to know
License-free
All 16 channels are legal across the EU and Switzerland. No registration, 0.5 W, done.
16 channels. Ever.
Codes are not extra channels — everyone shares the same 16 frequencies.
A code = a mute filter
Set the channel first (tap CH, then ▲ / ▼), then tap P1 and pick a sub-tone — or leave it off. A code only filters what YOU hear. On 04 -- you hear everyone on channel 4, even coded groups — but a group filtering for a code won't hear you unless you have the same code selected.
The only rule
Same channel + same code = you talk. For DCS, “same” includes normal vs inverted.
Codes don't unshare the air
A different code isn't a private line — everyone shares the channel. With a code set you only hear your own group, so you can't tell when others are mid-transmission and might talk over them. Set -- to hear through any code and check the channel's free first.
“-- --” hears everyone
On channel 4 with -- (code off) you hear every group on it, whatever code they use. But you send no code, so coded groups don't hear you — it's for listening in. To be heard, match a group's code.
What the radio offers
16
446.00625–446.19375 MHz
Channels
16 slots, 12.5 kHz apart, in the 446 MHz band. The CH knob picks one — the channel is the only thing that actually changes your frequency.
How it works: a channel is simply a preset frequency. Set CH 8 and the radio tunes its transmitter and receiver to 446.09375 MHz — everyone on that slot shares the same air.
52
60.0–254.1 Hz
CTCSS tones
Continuous Tone-Coded Squelch System
52 analog sub-tones that ride silently under your voice. Receivers set to the same tone open their speaker; everyone else stays muted.
How it works: while you talk, your radio hums one steady low tone the whole time (tone 16 = 114.8 Hz) — too low-pitched for the speaker to reproduce, so nobody hears it. A receiver opens its speaker only while it detects that exact hum.
210
105 × dn + di
DCS codes
Digital-Coded Squelch
105 digital codes, each usable normal (dn) or inverted (di) — 210 in total. Same mute-filter job as CTCSS, just digital: your group must match code AND polarity.
How it works: same idea, but instead of a hum your radio repeats a slow digital code word under your voice for the whole transmission — not a beep at the start. Receivers open only while they decode their code, and a short end-burst closes them without a static crackle.
DCS code table — manual (PDF) →