1 Take over the radio
This app and the stock walkie-talkie app cannot share the radio. Open Device and tap Take over: the stock app is paused and its icon hidden until you tap Hand back. The app needs Magisk root to reach the radio's serial port; allow it when Magisk asks. If taking over fails partway, the stock app is switched back on, so the phone is never left without a working radio app.
2 Pick a channel
On the Intercom page the round arrows step through your channels. Or open Channels and tap a card, then Use. The first time (and whenever the list is empty when SignalDeck takes the radio) it asks whether to import your channels from the stock app; Start empty skips it and is remembered. Channels can be edited, added, backed up and restored.
3 Talk and listen
Hold the large round key, or the phone's side PTT button, to talk; release it to listen. The key is amber when idle, green while the radio hears someone and red while you transmit. SignalDeck ends a voice transmission after 28 seconds. The radio's own limit is 120 seconds.
The launch screen
When SignalDeck opens it shows its launch screen for about two and a half seconds, with the version number near the bottom, while the radio comes up behind it. Tap it to skip. Going back to the app while it is still open (launcher icon, recent apps, a notification) never shows it again; it plays only after the app was closed.
4 Hear more
Turn on SOFT SQ to hear weaker stations without static, TXT to read live captions of what is said, and SCAN to search the channels of a zone for activity. Each has its own topic in this guide.