Keyboard
Keyboard & Controls
The RT-900 has a front-panel keypad with dedicated function keys and a numeric pad, plus three side buttons (PTT, PF2, PF3). Here's what every key does.
Physical Key Layout
The front panel has six dedicated function keys across the top and a standard 4x3 numeric pad below. The left side of the radio body has three buttons.
| Area | Keys |
|---|---|
| Function keys | MENU, UP, DOWN, EXIT, A/B, VFO/MR |
| Number pad (4x3) | 1 2 3 / 4 5 6 / 7 8 9 / * 0 # |
| Side buttons (left) | PTT (large, top), PF2 (middle), PF3 (bottom) |
| Top knobs | Power/Volume (left), Channel/Frequency (right) |
The firmware scans the keypad internally as a 5x4 matrix, but the physical layout groups the keys as function keys + number pad as described above.
Key Functions by Mode
Each key behaves differently depending on whether the radio is in VFO mode, Channel mode, or Menu mode.
| Key | VFO Mode | Channel Mode | Menu Mode |
|---|---|---|---|
| 0–9 | Frequency entry | Channel number select | Option value |
| UP | Frequency up | Next channel | Scroll up |
| DOWN | Frequency down | Previous channel | Scroll down |
| MENU | Open menu | Open menu | Confirm / enter sub-menu |
| EXIT | Cancel / back | Cancel / back | Exit menu level |
| * | Start scan | Start scan | — |
| # | Toggle key lock | Toggle key lock | — |
| VFO/MR | Toggle VFO/Memory mode | Toggle VFO/Memory mode | — |
| A/B | Switch VFO A/B | Switch VFO A/B | — |
| PTT | Transmit (hold) | Transmit (hold) | — |
| PF2 | Programmable (default: FM Radio) | Programmable (default: FM Radio) | — |
| PF3 | Programmable | Programmable | — |
Programmable Side Key Functions
The side buttons PF2 and PF3 can be assigned to any of these 7 functions via menu items 46 (PF2 Short), 47 (PF2 Long), and 48 (PF3):
| Option | Function |
|---|---|
| None | No action |
| Torch | Toggle flashlight/LED |
| Power | Cycle TX power level |
| Scan | Start/stop frequency scan |
| VOX | Toggle voice-activated TX |
| Alarm | Activate alarm mode |
| Radio | Toggle FM radio mode |
Long-Press Shortcuts
Each number key has a long-press shortcut that jumps directly to a common function:
| Key (long) | Function |
|---|---|
| 1 | SCAN |
| 2 | Memory Channel (store) |
| 3 | Frequency Step |
| 4 | Power Select (H/M/L) |
| 5 | Squelch |
| 6 | Dual Standby toggle |
| 7 | CTCSS sub-tone |
| 8 | Shift Direction |
| 9 | Offset |
| 0 | FM Radio |
| * | DTMF edit |
| # | Keypad Lock |
Long Press & Repeat
long pressLong press triggers after holding a key for approximately 1 second (100 × 10ms ticks).repeat keysKeys that support continuous repeat while held: UP, DOWN, VFO/MR, *, #, 0, 8, EXIT, PF2, PF3repeat rateRepeat interval is approximately 140ms while the key is held down.