Sub-GHz FAQ

Practical answers to common Sub-GHz problems: wrong band, noisy decodes, antenna errors, and false expectations.

How do I pick the right frequency band?

Start with regulatory labels or product documentation. Common ISM variants include 433 MHz, 868 MHz, and 915 MHz depending on region. Guessing the band is the fastest path to wasted time.

Why are decodes inconsistent between runs?

• Antenna mismatch for the actual band
• Receiver gain too high (front-end overload)
• Noisy RF environment
• Variable distance/orientation in test setup

Does replay always work?

No. Rolling codes and challenge-response mechanisms are specifically designed to defeat simplistic replay patterns. Failed replay can be expected defensive behavior.

What is the best baseline setup?

1. One known transmitter/target pair you own.
2. Correct tuned antenna for that exact band.
3. Fixed distance and orientation.
4. Multiple repeated captures before any changes.

How do I improve reliability quickly?

Lower gain, improve antenna matching, reduce environmental noise, and change one variable at a time with logging.