PTT Modes

Push-to-talk on VoxDMR is a software trigger. There’s a key (or hardware button), an on-screen button, and a setting that controls how either of them behaves. This page covers the two PTT modes and how to bind the trigger to a different key.

The two modes

Desktop: open Settings → PTT. The PTT mode picker has two choices.

Android: open the Settings tab. Under Session, the PTT mode segmented button has two choices.

Push to talk (default). Hold the key (or hold the on-screen button) to transmit. Release to stop. The classic radio behavior. This is what you want if PTT is muscle memory for you and you don’t want to think about state.

Toggle / Tap: tap the key once to start transmitting, tap again to stop. Useful for long announcements, net check-ins, or any situation where holding a key gets uncomfortable.

You can switch modes mid-transmission. The TX state itself doesn’t change — only how subsequent presses are interpreted.

The PTT key

By default, Spacebar triggers PTT. You can rebind it to almost any key.

To rebind:

  1. Open Settings → PTT.
  2. Under PTT key, click the button that shows the current key (e.g. Space Change).
  3. The button changes to Press a key… (Esc to cancel).
  4. Press the key you want as your new PTT.
  5. The button updates to show the new label. Done. The binding is saved.

If you change your mind mid-capture, press Esc or click the button again to cancel.

What you can bind

  • Any letter or number (A-Z, 0-9).
  • Any function key (F1-F12).
  • Most named keys: Space, Tab, Enter, Insert, Home, End, PageUp, PageDown, the arrow keys, etc.
  • Symbols, ,, ., ;, [, ], etc.

What you can’t bind

VoxDMR refuses to bind PTT to a pure modifier key:

  • Shift, Ctrl, Alt, AltGr, Meta / Super / Hyper
  • Caps Lock, Num Lock, Scroll Lock

Modifiers are used by the OS and other apps for shortcuts; if PTT was bound to Ctrl you’d key the radio every time you copied something. Press another key during capture and VoxDMR ignores the modifier-only press.

Modifier combinations (e.g. Ctrl+F1) aren’t supported either. Only single keys. If you need a hard-to-hit key, F8 / F12 / Insert are common choices that don’t conflict with anything else.

Talkgroup and scan hotkeys

The PTT tab has three more optional hotkeys, all unbound by default:

  • Next talkgroup key — cycle the active talkgroup to the next favorite.
  • Previous talkgroup key — cycle to the previous favorite.
  • Scan toggle key — arm or disarm talkgroup scan.

Bind each one the same way as the PTT key: click Set, then press the key you want (Esc to cancel). Like the PTT key, these only fire while the main window has keyboard focus — VoxDMR never grabs a global hotkey, so they do nothing while another app is focused.

Hardware keys

Android phones don’t have a spacebar, but most have volume keys, and many headsets or BT remotes expose extra buttons. You can bind any of them to PTT.

  1. Open the Settings tab.
  2. Scroll to the Hardware section.
  3. Tap Hardware key binding. The button enters capture mode — press the key you want to use.
  4. Tap again to clear the binding.

The Hide on-screen button toggle below it is always available — turn it on if you’d rather rely entirely on the hardware button and reclaim the screen space. If you hide it without a PTT key bound, VoxDMR warns first with a No way to transmit confirm, since you’d have no way to key up until you re-enable the button or bind a key.

Bluetooth headset buttons, volume rockers, dedicated PTT keys on rugged phones — all work as long as Android delivers the key event to the foreground app. Some launchers and accessibility services intercept volume keys for their own use; if the bind doesn’t trigger PTT, try a different key.

Keep screen on under the same Hardware section keeps the display awake while VoxDMR is in the foreground — useful for net check-ins where you don’t want the screen to dim mid-conversation.

The on-screen button

The big red TX button on the main window does exactly what the PTT key does, in whichever mode you’re in. It also respects the mode:

  • Push to talk: press and hold the mouse button on TX to transmit; release to stop.
  • Toggle: click TX once to start, click again to stop.

Useful if you don’t want to or can’t use the keyboard. It’s disabled until you’re connected and subscribed to a talkgroup; hover over it for a tooltip explanation when greyed out.

You can also hide the on-screen button on desktop: toggle Hide on-screen PTT button under Settings → Interface, in the Display card.

Talk-permit tones

Optional walkie-talkie-style beeps: a short rising arpeggio when you key up and a falling one when you release. Off by default, so nothing changes until you enable them. The tones play locally only — they are never sent on air.

With tones on, keying is deferred around them: on key-down VoxDMR plays the rising beep, waits for it to finish (~300 ms), then opens TX; on release it closes TX first, then plays the falling beep. Releasing during the rising tone aborts entirely — TX never opens and nothing transmits, exactly like a real radio’s talk-permit tone. (With tones off, keying is immediate.) The key-down beep is also suppressed when the channel is busy, since a half-duplex key-up would be rejected anyway.

Enable them in Settings → Audio, in the Transmit card: PTT tones (rising on key-down, falling on key-up).

Enable them in Settings → Push-to-talk: the PTT tones switch (Play a rising beep on key-down and a falling beep on key-up). The TOT time-out warning now beeps too.

How you know you’re transmitting

While you’re keyed up, three things change:

  • The TX button on the main window turns solid red.
  • The bottom bar shows TX HH:MM:SS ticking up. Your transmission length.
  • The TX level meter goes live.

When idle, the bottom bar shows a hint instead, HOLD SPACE in push-to-talk mode or TAP SPACE in toggle mode (with whatever key you’ve actually bound).

Window / app focus

Desktop: VoxDMR’s PTT key works any time the main window has keyboard focus. If you’re typing into another app and press your PTT key there, VoxDMR doesn’t see it. Click the VoxDMR window first.

(VoxDMR doesn’t grab a global hotkey. That’s a deliberate decision — it would race with desktop shortcut managers and require extra OS permissions.)

Android: the hardware-key binding works any time VoxDMR is the foreground app. While the app is in the background, Android routes key events to whatever’s in front. To keep PTT available without unlocking the phone, leave VoxDMR foregrounded and turn on Keep screen on.

Edge cases

Switching modes while transmitting. Allowed. The current TX continues; only the next key press follows the new mode’s rules.

Disconnecting while transmitting (toggle mode). TX stops automatically when you disconnect or lose subscription, even if you’d toggled it on. You don’t have to remember to tap the key off.

The key getting stuck. If your OS swallows the key-up event (e.g. you Alt-Tabbed mid-press in push-to-talk mode), tapping the PTT key once more should clear it. If not, click the on-screen TX button to release.

Switching talkgroups while keyed (Android). Blocked. While you’re transmitting, favorite and rail taps, the hardware next/previous keys, a rotary knob, and the car-mode cycler are all ignored, so a stray shortcut can’t reroute a live transmission to another group. Release PTT first, then switch.

Next steps

Previous
← Talkgroups
Next
Car Mode →