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Docs Build & Assembly Dummy Load and Bench Testing

Dummy Load and Bench Testing

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Test 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

  1. Solder a 50 ohm resistor (or two 100 ohm in parallel) rated for at least 1-2 W.
  2. Connect it between the SMA center and ground.
  3. 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

  1. Connect the dummy load to the E22 SMA.
  2. Power the beacon and enter BEACON mode.
  3. Confirm the serial log shows a clean TX cycle.
  4. Check the OLED progress bar and the audio click stream.
  5. The only thing missing is radiation - everything else is verified.

Why Bother

BenefitDetail
No interferenceNeighbors’ radios unaffected
SafeNo RF near eyes or people
LegalNo unlicensed on-air tests
ConsistentMeasurable, repeatable TX checks