Testing the Heltec V4 shows that higher TX settings don’t always mean more power. The hardware eventually levels off, meaning settings and actual output don’t scale one-to-one.
Measured Gain and Current Table
| TX Setting | Actual Output (dBm) | Current Draw (mA) | Notes |
|---|---|---|---|
| 16 | +25.34 dBm | 468 mA | Good for low-power nodes |
| 17 | +27.14 dBm | 589 mA | High-efficiency threshold |
| 18 | +27.31 dBm | 605 mA | The “Sweet Spot” |
| 19 | +27.58 dBm | 637 mA | Marginal gains |
| 20 | +27.74 dBm | 709 mA | Practical maximum |
| 22 | +28.44 dBm | 741 mA | Hard firmware limit |
Recommended TX Power Setting
For the best balance of range and battery life, the recommended setting is TX 18.
Credits & Source: This data was compiled from community benchmarks performed by JasonKrijgsman and calibrated measurements by towerviewcams.
For the full technical discussion and raw data, see the original GitHub issue: MeshCore Issue #1708: Heltec V4 Measured TX Power Output Table