JA3RSJ — FT8 activity observed at SO8OO

DXCC entity inferred from callsign: Japan

Receiver-side FT8 activity involving JA3RSJ, decoded by SO8OO in southeastern Poland. 5 FT8 messages attributed to this token as transmitter, on 20m, across 1 UTC dates in the available aggregate history. Last observed 2026-06-06.

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 5 FT8 messages attributed to JA3RSJ 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 -11 dB; no usual signal pattern is inferred.

Overview

5
Messages attributed
1
UTC dates decoded
1
Active 15-min windows
-11 dB
Estimated median S/N

Bands

First attributed message: 2026-06-06
Last attributed message: 2026-06-06 20:28 UTC

Observed FT8 message patterns

Attributed sample
5 messages
Active dates
1 UTC dates
Estimated median S/N
-11 dB
S/N percentile sample
Too small
Recurring-pattern threshold
Not met

SO8OO display ranges among successful decodes: weak (≤ -16 dB) 1, moderate (-15 to -9 dB) 2, strong (≥ -8 dB) 2.

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 JA3RSJ in decoded directed-looking exchanges:

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 UTCBandJA3RSJ S/NCounterpartCounterpart S/NMsgsCapture
09-06 19:54 40m - / -20 HA1TIB 0 / - 2 Partial capture
09-06 19:44 40m - / -20 LZ5UY -2 / - 2 ✓ Closing fragment
08-26 02:56 20m - / -19 K2TQC -13 / - 2 Partial capture
08-22 19:16 20m - / -19 EB5AL +2 / - 6 ✓ Closing fragment
08-04 22:44 20m - / -24 EA8UP -12 / - 2 ✓ Closing fragment
07-25 20:05 20m - / -11 EA5ISM -12 / - 2 ✓ Closing fragment
07-12 20:01 20m - / - EA5W -7 / - 7 ✓ Closing fragment
06-27 20:38 20m - / -8 SP4JAW -8 / - 2 Partial capture
06-27 20:31 20m - / -5 IZ2DPX +2 / - 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
194400  -2 1375  JA3RSJ LZ5UY -20 (x2)
195400  +0 1191  JA3RSJ HA1TIB -20 (x2)
20m
UTC    dB Audio  Message
200445  -3  579  JA3RSJ EA5W IM97 (x2)
201730 -10  855  JA3RSJ M8KKH JO01
200500 -11 1566  JA3RSJ EA5ISM -11 (x2)
224400 -11 1368  JA3RSJ EA8UP -24 (x2)
191600  +2  633  JA3RSJ EB5AL IM99 (x6)
025615 -15  932  JA3RSJ K2TQC -19 (x2)

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