JA5DNJ — FT8 activity observed at SO8OO

DXCC entity inferred from callsign: Japan Most frequent locator attributed to this token: PM63

Receiver-side FT8 activity involving JA5DNJ, decoded by SO8OO in southeastern Poland. 15 FT8 messages attributed to this token as transmitter, on 20m, across 1 UTC dates in the available aggregate history. Last observed 2026-06-19.

These are automated observations at the SO8OO receiver, not an official contact log. Times are UTC. Attribution follows decoded FT8 message structure: CQ uses the first token and directed-looking messages use the second. Free text that resembles a directed message can be attributed imperfectly. Summary S/N reflects propagation plus SO8OO receiver, antenna and local-noise conditions. Counts are not adjusted for monitoring outages; transmissions that were not decoded are absent. Inferred entity and location data may be inaccurate for portable, remote or special-event operation.

SO8OO decoded 15 FT8 messages attributed to JA5DNJ as the transmitting token by decoded message structure across 1 UTC dates in the available aggregate history. The largest monitored-band total was 20 m (100%). In this small sample, the estimated median decoder S/N was -1 dB; no usual signal pattern is inferred.

Overview

15
Messages attributed
1
UTC dates decoded
1
Active 15-min windows
-1 dB
Estimated median S/N

Bands

First attributed message: 2026-06-19
Last attributed message: 2026-06-19 21:13 UTC

Observed FT8 message patterns

Attributed sample
15 messages
Active dates
1 UTC dates
Estimated median S/N
-1 dB
S/N percentile sample
Too small
Recurring-pattern threshold
Not met

SO8OO display ranges among successful decodes: weak (≤ -16 dB) 0, moderate (-15 to -9 dB) 0, strong (≥ -8 dB) 15.

WSJT-X defines S/N reports against a 2,500 Hz reference noise bandwidth. The ranges above are SO8OO receiver-side display categories, not official WSJT-X classes, transmitter-power measurements or estimates of how easy the station is to hear elsewhere. Statistics include only successful decodes on SO8OO's monitored FT8 channels; transmissions that were not decoded are absent. The sample does not meet the threshold for a recurring time or signal-pattern claim (20 attributed messages, three UTC dates and five distinct 15-minute windows).

Frequent counterpart tokens observed at SO8OO

Tokens most often paired with JA5DNJ in decoded directed-looking exchanges:

Most frequent locator attributed to JA5DNJ

The map compares the centres and boundaries of the locator field attributed to this token by decoded message structure, 2° × 1° as a Maidenhead square, and SO8OO's six-character receiver square. The separation is not an exact antenna-to-antenna distance or a radio-path length.

Attributed locator
PM63 · 13 decoded messages
SO8OO receiver locator
KN09VW
Locator-centre separation
8,540 km (approx.)
Last such locator decoded
2026-06-19 21:12 UTC

A decoded locator can describe portable, remote or special-event operation and is not proof of a permanent station address or transmitter identity.

Observed FT8 exchanges

S/N cells show: decoded at SO8OO / report transmitted by the counterpart. An observed exchange is not a QSL or an official logbook confirmation.

Time UTCBandJA5DNJ S/NCounterpartCounterpart S/NMsgsCapture
09-08 20:47 40m - / -20 5B4AMM -12 / - 2 ✓ Closing fragment
08-28 09:30 10m - / - IW3IBN -4 / - 2 Partial capture
08-28 09:27 10m - / -8 LZ3BS -10 / - 3 ✓ Closing fragment
08-28 09:24 10m - / -14 Z34K +8 / - 2 ✓ Closing fragment

Recent FT8 messages decoded at SO8OO

Frequency values are decoder audio offsets in hertz, not RF frequencies.

40m
UTC    dB Audio  Message
204730 -11 2362  JA5DNJ 5B4AMM -20 (x2)
10m
UTC    dB Audio  Message
133215  -6 2719  JA5DNJ IT9CCB RRR
092400  +7  557  JA5DNJ Z34K -14 (x2)
092730 -16 2421  JA5DNJ LZ3BS R-08 (x3)
093030  -3 1191  JA5DNJ IW3IBN JN55 (x2)

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