Dummy Load and Bench Testing
Edit on GitHubTest transmissions without radiating: a 50 ohm dummy load and safe bench procedure
Dummy Load and Bench Testing
Overview
A dummy load absorbs the TX power instead of radiating it, letting you test the full transmit path on the bench without putting a signal on the air or near people.
Building a 50 Ohm Load
- Solder a 50 ohm resistor (or two 100 ohm in parallel) rated for at least 1-2 W.
- Connect it between the SMA center and ground.
- Mount it in a small metal box or clip a heat sink to it.
Warning
At +30 dBm the load dissipates ~1 W. A 0.25 W resistor burns out instantly; use a 2 W part or bigger.
Bench Test Procedure
- Connect the dummy load to the E22 SMA.
- Power the beacon and enter BEACON mode.
- Confirm the serial log shows a clean TX cycle.
- Check the OLED progress bar and the audio click stream.
- The only thing missing is radiation - everything else is verified.
Why Bother
| Benefit | Detail |
|---|---|
| No interference | Neighbors’ radios unaffected |
| Safe | No RF near eyes or people |
| Legal | No unlicensed on-air tests |
| Consistent | Measurable, repeatable TX checks |