Initial FM-Band Receive-Chain Validation

Can each documented receive chain capture a previously observed local FM-band signal as complete, reproducible evidence without clipping or bypassing the provenance gate?

Every accepted raw capture was sealed with receiver, RF-path, timing, configuration, sample-count and SHA-256 provenance before deterministic analysis. The expected occupied region was offset from receiver DC.

• Receive only; no transmission path or active RF probing.
• Run deterministic spectrum and statistical checks before any reasoning model.
• Retain the failed preliminary attempt to make selection history visible.
• Do not infer a station or modulation identity from frequency alone.

One HackRF capture and two NESDR captures passed the initial evidence gate. Each contained an occupied region near 100.7 MHz with no detected clipping under the recorded settings.

A preliminary HackRF attempt at a different tested frequency did not meet the known-signal gate and remains preserved. The passing captures validate the receive and evidence paths; they do not calibrate absolute RF power or identify the broadcaster.

The NESDR driver emitted an initial tuner phase-lock warning before the requested tune. Two captures with different receiver centers subsequently placed the same occupied region on the expected opposite sides of baseband. The warning remains open for driver-level characterization.

Both documented receive chains passed the initial known-signal evidence gate. This supports cautious environmental mapping and later controlled calibration tests.

No observation in this record is evidence of an unexplained anomaly.