RexySDR daily RF report — 2026-10-06

Rolling 24-hour evidence window; see source limitations

Historical report for 2026-10-06; this page is not a live observation. Values are relative and uncalibrated. Source limitations remain authoritative; complete capture coverage is not established.

Plain-English summary

- The receiver reported a full day of measurements on all eight bands with no gaps in collection, so the data is complete and current.

- Two visible level shifts stood out on the long-running band readings: the 160m band stepped down sharply around 21:35 UTC one evening, then stepped back up around 04:25 UTC the next afternoon, and stayed higher for the rest of the day. The 10m band showed a brief rise lasting about half an hour around 08:25 UTC, then returned to its usual level.

- A separate wideband snapshot analysis flagged the 160m and 10m bands for routine operator screening attention because a measured level in one processing channel has held at a new value across many snapshots. This is a screening aid only — not a warning, not a fault finding, and not a measurement of interference.

- Daytime decoding activity was dominated by the 20m and 40m bands; this is reported as an observation only and does not tell us anything about signal paths or causes.

- Historical comparison records are still young: comparisons at this time of day cannot yet be made numerically, and general "normal behaviour" for this station is not yet established.

- Nothing in this evidence package supports naming a cause — not sky conditions, not weather, not any device — and nothing here is labelled interference.

Observation status

- Latest eight-band RF observation: id 19968 at 2026-10-05T20:19Z, completeness 8/8 bands, freshness 94 s at contract generation.

- 24h series: 289 points at 5-minute sampling (full expected coverage for the window).

- P20 wideband snapshot: observation 261005_200230 at 2026-10-05T20:02:30Z (≈17 min before window end), completeness 1, scan 13.05 s, 12,500 points over 5 kHz–62.5 MHz at 5 kHz spacing; 12,431 valid bins, 69 excluded DC-hole bins; all file hashes verified; A and B channels share identical valid-bin masks.

- Time-conditioned and environmental context objects were both generated from the same P20 observation (261005_200230) as the daily P20 snapshot — no observation mismatch.

Eight-band RF behaviour

Deterministic min/median/max over 289 samples (relative dB, uncalibrated):

| Band | Min | Median | Max | Span |

|---|---|---|---|---|

| 160m | -80.71 | -66.04 | -62.83 | 17.9 dB |

| 80m | -81.27 | -79.34 | -77.39 | 3.9 dB |

| 40m | -75.12 | -72.49 | -70.64 | 4.5 dB |

| 30m | -80.17 | -78.82 | -75.88 | 4.3 dB |

| 20m | -79.92 | -79.16 | -75.62 | 4.3 dB |

| 17m | -76.45 | -74.53 | -72.64 | 3.8 dB |

| 15m | -84.51 | -82.08 | -80.77 | 3.7 dB |

| 10m | -92.03 | -91.61 | -82.79 | 9.2 dB |

Measured structure within the window (facts, not interpretations):

- 160m held higher levels (~-65 to -70) from window start until 21:30Z on 4 Oct, stepped down ~10.6 dB to ≈-80.6 within one 5-min sample at 21:35Z, remained ≈-79/-80.7 until 04:20Z, then stepped up ~10.5 dB at 04:25Z and stayed in the -63 to -67.8 range for the rest of the day (window end -64.1).

- 80m, 40m, 30m, 20m, 17m, 15m moved within ~4 dB bands with gradual trends; e.g. 30m drifted from ~-78.8 to ~-80.0 hour-mean over the last 12 h of the window; 15m rose from ~-84 hour-mean (21Z) to ~-81.4 (02–03Z).

- 10m sat near -90.4 to -92.0 except a transient at 08:25Z–08:50Z on 5 Oct reaching -82.8/-82.9 (peak hourly mean -87.0), returning to baseline by 08:55Z. 20m (-75.6 to -76.8), 30m and 80m showed smaller shifts in the same 08:25–08:50Z window.

- Band ordering by median measured level: 160m highest, then 40m/17m, 30m/20m/80m, 15m, with 10m lowest. These are relative channel readings; no absolute sensitivity is defined.

P20 wideband evidence

Single snapshot 261005_200230 (deterministic features from one observation; no change-over-time may be inferred from it):

Global channel statistics (Power A and Power B are two parallel measurement channels; their physical meanings are not defined by this package):

- Power A: median -70.78, p90 -54.47 (+16.3 above median), p99 -43.39 (+27.4), MAD 3.60 dB; 4,481/12,431 bins (36.0%) >median+6 dB. Strongest peak: 1.325 MHz at -24.24 dB_rel (+46.5 above global median), with a cluster of high peaks between 0.92 and 1.84 MHz and one at 6.02 MHz.

- Power B: median -72.46, p90 -61.96 (+10.5), p99 -48.98 (+23.5), MAD 1.77 dB; 2,317/12,431 bins (18.6%) >median+6 dB. Strongest peak: 15.720 MHz at -17.03 dB_rel (+55.4 above global median); next 35.9 MHz (+44.0), 0.065 MHz (+39.2), 0.020 MHz (+37.5).

- A−B difference: median +1.13 dB, p10 -4.15, p90 +16.44, MAD 2.98 dB.

FT8-neighbourhood analysis windows (±100 kHz; analysis regions, not band allocations):

- 160m (1.84 MHz centre) is the standout in both channels: A window median -48.2 dB_rel, peak exactly at 1.840 MHz (+21.9 above window median), 2/41 bins active; B median -69.9, peak at 1.840 MHz (+18.8), 2/41 active.

- All other seven windows have 0 active bins in both channels. Window medians: A ranges -48.2 (160m) to -71.7 (10m); B ranges -56.8 (17m) to -74.1 (30m). Notably high B-window medians in 20m (-60.3) and 17m (-56.8) versus other windows' ~-70s, with window peaks within 1.9–2.9 dB of window medians.

Historical P20 evidence

Available; archive of 53 observations, maturity BASIC_HISTORY_AVAILABLE. All three references (previous, ~1 h earlier, previous day same time) resolved; cadence valid on all bands (gaps ≈29.98 min), so persistence statements are permitted by the contract.

Deterministic changes for snapshot 261005_200230:

- 160m: A median +1.49 dB vs 1 h earlier, +0.71 dB vs previous day; top-tail (p99-above-median) A +6.67 dB vs 1 h and +8.13 dB vs previous day (B +7.17/+8.09 dB). Persistence recorded active on channel A: trigger observation 261005_043231, 32 occurrences, ≈930 minutes, reason "active_persistent_step". Shadow attention 24.07 — MEDIUM (highest in the set) — with flag PERSISTENT_LEVEL_SHIFT.

- 10m: persistence recorded active on channel A: trigger 261005_090230, 23 occurrences, ≈660 minutes. Shadow attention 17.98 — LOW — flag PERSISTENT_LEVEL_SHIFT. Median deltas are small (A +0.05 dB vs previous, -0.18 dB vs previous day).

- 17m: A +1.97/+2.07 dB vs previous/1 h; B median +2.36 dB vs previous, +4.98 dB vs previous day same time — the largest day-over-day median shift in the set. Shadow 15.52 LOW.

- 15m: A +2.41 dB vs previous day. 80m/40m/30m/20m: median deltas within ±1.6 dB; shadow scores 1.64–9.63, all LOW, no flags. No active persistence on these six bands.

Cautions: shadow attention scores are operator-screening values only — not probabilities, not anomaly scores, not RF classifications. The archive spans only days-to-weeks of half-hourly observations; persistence descriptions are deterministic records, not classifications, and anomaly classification is not permitted.

Time-conditioned reference status

Status: INSUFFICIENT.

- The current P20 observation falls in the local-time bucket 06:00–09:00 Australia/Brisbane (observed 2026-10-06T06:02:30+10:00).

- Every band/channel metric shows reference_sample_count = 6 across only 1 distinct local day. The maturity rule requires ≥2 distinct local days for DEVELOPING; therefore the system does not yet have enough independent same-time-of-day history to describe normal behaviour for this bucket.

- Accordingly, all delta_from_reference_median and robust_z values are null (suppressed) — deterministic numeric comparison against the time-conditioned reference is not available today. Reference medians exist (e.g. 160m A bucket median -55.17 dB_rel) but should not be treated as an established same-time baseline.

- The time-conditioned evidence was generated from observation 261005_200230 — the same observation as the daily P20 snapshot — so there is no cross-observation comparison issue.

- Even once numeric comparison unlocks, robust-z or values outside p10–p90 remain deterministic comparisons, not anomaly probabilities.

Environmental context

Described in ordinary language; context only, with no causal implication for RF behaviour:

- Solar geometry (computed from the P20 observation time and site coordinates): at 20:02:30Z the Sun sat 0.66° above the geometric horizon, azimuth ~95° (east), declination -4.5° — local sunrise at the site. In the separate top-level environment block evaluated ~17 min later (20:19Z), elevation was 4.68°. Solar phase is not proof of any propagation mode or path behaviour.

- Regional space weather (BOM, Australian region — not measurements at the antenna): daily A-index 22 valid from 2026-10-04 00:00 (an older regional value), K-index 2 valid 2026-10-05 18:00Z, Dst -18/-19 valid ~19:45–19:55Z. No magnetic alerts; one magnetic warning in effect for 2026-10-05 attributed to a coronal hole, geomagnetic forecast G0–G1.

- Local meteorology (Open-Meteo model grid cell centred -16.977, 145.657, elevation 490 m — not a co-located physical weather station), valid 20:00Z: 14.2 °C, relative humidity 99%, dew point 14.0 °C, apparent 14.8 °C, no precipitation, partly cloudy (54% cloud), MSL pressure 1019.1 hPa (surface 961.7 hPa), wind 5.2 km/h from 202° with gusts to 14.4 km/h.

- Environmental context observation = 261005_200230, the same observation as the daily P20 snapshot; alignment offset -150 s for the meteorology field. No causal relationship between any of the above and measured RF levels is asserted or implied.

FT8 observational evidence

- Window coverage: 1,345 minutes recorded, 1,337 active, 24,032 declared decodes (2026-10-04T20:19Z → 2026-10-05T20:19Z).

- Band activity (decodes / active minutes / unique calls / mean SNR / strongest SNR):

- 20m: 12,067 / 929 / 795 / -6.28 dB / +21 dB

- 40m: 4,317 / 820 / 318 / -7.92 dB / +13 dB

- 15m: 3,607 / 763 / 384 / -8.84 dB / +17 dB

- 17m: 1,330 / 395 / 193 / -9.33 dB / +6 dB

- 30m: 1,237 / 465 / 120 / -9.57 dB / +8 dB

- 10m: 1,144 / 357 / 120 / -6.27 dB / +16 dB

- 80m: 325 / 159 / 24 / -5.77 dB / +9 dB

- Recent decodes at window close are mostly 40m (e.g. HS0ZOY, VK3AMP, EA8UP) with 20m present (VK2LAW, grid QF56, +7 dB).

- FT8 is observational evidence only. Decode counts and SNR values do not establish propagation mode, path quality, distance, or any causal explanation; SNR alone does not imply station proximity. No 160m or (as listed) additional-band FT8 activity is present in this summary beyond the seven bands shown.

Historical-reference status

- Eight-band (P19/D1) historical reference: 17 candidate cycles found around the same-time-of-day window (±30 min), 11 qualified; maturity_status UNQUALIFIED — the rule "Q≥4 has not yet been qualified as sufficient" — with rf_state INSUFFICIENT and anomaly_status INSUFFICIENT. classification_permitted = false.

- Scope note: D1 history is keyed by station_id and time, not by test-site coordinates, so it is not location-stratified.

- Consequence: no normal-behaviour baseline for the eight-band series is established yet; same-time comparisons remain descriptive-only and immature, and no anomaly labelling is possible.

- P20 historical reference is at BASIC_HISTORY_AVAILABLE (53 observations) and time-conditioned reference is INSUFFICIENT — all three maturity tracks remain immature; none of them enables classification on their own.

Notable measured changes

Deterministic calculations from supplied measurements (no classifications):

1. 160m eight-band level: step down ≈10.6 dB at 21:35Z 4 Oct; step up ≈10.5 dB at 04:25Z 5 Oct; sustained higher levels (-63 to -67.8) for ~16 h after the rise.

2. 10m eight-band level: ≈+7.6 dB transient at 08:25Z–08:50Z 5 Oct, returning to baseline by 08:55Z (≈30 min), with smaller concurrent 20m (+~3 dB), 30m and 80m shifts.

3. P20 vs previous day same time: 160m top-tail energy up ≈8.1 dB (A) and ≈8.1 dB (B) above median scale, window median up 0.71 dB (A); 17m B median up ≈4.98 dB; 15m A median up ≈2.41 dB.

4. P20 persistence records: 160m channel A active since 261005_043231 (32 occurrences, ≈930 min; shadow MEDIUM screening attention); 10m channel A active since 261005_090230 (23 occurrences, ≈660 min; shadow LOW attention with persistence flag).

5. Single-snapshot P20 facts: 160m analysis window is the only window with active bins (2/41 both channels); Power B's largest peak sits at 15.720 MHz, +55.4 dB above its global median; Power A's highest peaks cluster between 0.92 and 1.84 MHz.

6. Gradual hour-mean drifts: 30m down ≈1 dB across the daylight half of the window; 15m up ≈2.5 dB from its lowest overnight hour-mean; 17m A/B window levels are the highest B-channel window medians in the snapshot.

Cross-source observations

- Timing coincidence: the 160m persistence trigger (P20 observation 261005_043231, 04:32Z) follows the 04:25Z +10.5 dB 160m step in the eight-band series by ~7 minutes. These are different measurement pipelines; coincidence of timing is reported, identity of signal is not established.

- Timing coincidence: the 10m persistence trigger (261005_090230, 09:02Z) is ~7 minutes after the eight-band 10m transient ended (08:55Z). Same caution applies.

- The P20 snapshot's 160m window peak at 1.840 MHz lies inside the analysis window whose eight-band counterpart stayed at its higher daytime level when the snapshot was taken (20:02:30Z, ~-64.5 at the nearest series sample) — directionally consistent, though absolute agreement is not expected between the two pipelines.

- Power B's dominant 15.720 MHz peak sits between the 15m and 17m analysis-window centres; whether anything was happening there earlier or later is not determinable from a single P20 observation.

- FT8 20m shows the most decodes while the eight-band 20m level is mid-pack; FT8 activity and P20/8-band levels are reported independently, with no correspondence claimed.

- Environmental readings (sunrise geometry, regional G0–G1 forecast, cool near-saturated morning) coincide in time with the higher 160m period; coincidence is noted, causation is explicitly not inferred.

What cannot yet be concluded

- Cause of any change: propagation, ionospheric conditions, space weather, meteorology, or any local source are not established as causes of anything in this report.

- Anomaly/RFI classification: forbidden by the contract (rf_classification_permitted=false, anomaly_classification_permitted=false). Shadow MEDIUM attention on 160m is screening priority only.

- Time-conditioned numeric comparison: INSUFFICIENT (one local day of bucket history); no robust-z or percentile judgement is possible, now or by implication later.

- Eight-band historical baseline: UNQUALIFIED/INSUFFICIENT — "normal" for 20:19Z is not yet describable with confidence.

- Temporal evolution of P20 wideband features: the snapshot is one observation; the 15.72 MHz peak or the 1.84 MHz feature cannot be said to have risen, fallen, or persisted based on it alone.

- Meaning of Power A vs Power B channels: physical definitions absent; they are two parallel measurement channels only.

- Signal identity, distance, direction, or path of any peak or decode; source_identification is not permitted.

- Whether the eight-band steps and the P20 persistence triggers reflect the same underlying signal: plausible timing alignment only, uncorroborated.

- Absolute power levels or calibration: values are relative and uncalibrated.

- Material uncertainty: the historical archive is short (53 P20 observations; 11/17 qualified D1 cycles) and both channels' day-to-day variability at 06:00–09:00 local is essentially unconstrained, so the recorded persistence states could reflect ordinary immature-history behaviour; this cannot be resolved until multi-day time-conditioned references mature.

No RexySDR configuration changes are recommended by this report.