JR3DXJ — FT8 activity observed at SO8OO

DXCC entity inferred from callsign: Japan Most frequent locator attributed to this token: PM74

Receiver-side FT8 activity involving JR3DXJ, decoded by SO8OO in southeastern Poland. 26 FT8 messages attributed to this token as transmitter, on 20m, across 6 UTC dates in the available aggregate history. Observed between 2026-06-08 and 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 26 FT8 messages attributed to JR3DXJ as the transmitting token by decoded message structure across 6 UTC dates in the available aggregate history. The largest monitored-band total was 20 m (100%). Several six-hour UTC windows tied for the largest share (100%), so no unique busiest interval is claimed. Received S/N was mixed across SO8OO's weak, moderate and strong ranges; the estimated median was -16 dB.

Overview

26
Messages attributed
6
UTC dates decoded
9
Active 15-min windows
-16 dB
Estimated median S/N

Bands

First attributed message: 2026-06-08
Last attributed message: 2026-06-19 21:15 UTC

Observed FT8 message patterns

Attributed sample
26 messages
Active dates
6 UTC dates
Estimated median S/N
-16 dB
Estimated 10th-90th percentile
-20 to -9 dB
Recurring-pattern threshold
Met

SO8OO display ranges among successful decodes: weak (≤ -16 dB) 14, moderate (-15 to -9 dB) 10, 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.

Frequent counterpart tokens observed at SO8OO

Tokens most often paired with JR3DXJ in decoded directed-looking exchanges:

Most frequent locator attributed to JR3DXJ

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
PM74 · 17 decoded messages
SO8OO receiver locator
KN09VW
Locator-centre separation
8,565 km (approx.)
Last such locator decoded
2026-06-19 21:15 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 UTCBandJR3DXJ S/NCounterpartCounterpart S/NMsgsCapture
07-07 21:03 20m - / - DK4OX -5 / - 3 Partial capture
07-07 21:02 20m - / -24 IU4QQE -12 / - 4 ✓ Closing fragment
07-07 20:55 20m - / - DL1R +2 / - 8 Partial capture
07-07 20:55 20m - / - DM5WGL +1 / - 4 Partial capture
07-07 20:53 20m - / -3 4X1UF -7 / - 2 ✓ Closing fragment
07-07 20:51 20m - / -20 DK2SHS +2 / - 2 ✓ Closing fragment
06-26 20:35 20m - / - IU4RWW -3 / - 7 Partial capture

Recent FT8 messages decoded at SO8OO

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

20m
UTC    dB Audio  Message
205715  +0 2722  JR3DXJ DL1R JN58 (x5)
210245 -14 1931  JR3DXJ IU4QQE JN64 (x2)
210315  -3 2136  JR3DXJ DK4OX JO52
210345 -15 1931  JR3DXJ IU4QQE R-24
210345  -8 2136  JR3DXJ DK4OX JO52
210415 -10 1931  JR3DXJ IU4QQE 73
210415  -3 2137  JR3DXJ DK4OX JO52
223230 +14 2891  JR3DXJ TM74TFR -12
223300 +16 2891  JR3DXJ RR73; JI3CWI <...> +02
224830 -23 1598  JR3DXJ OY1R -18

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