JR4FNW — FT8 activity observed at SO8OO

DXCC entity inferred from callsign: Japan Most frequent locator attributed to this token: PM64

Receiver-side FT8 activity involving JR4FNW, decoded by SO8OO in southeastern Poland. 30 FT8 messages attributed to this token as transmitter, on 20m, across 2 UTC dates in the available aggregate history. Observed between 2026-06-11 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 30 FT8 messages attributed to JR4FNW as the transmitting token by decoded message structure across 2 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 -12 dB; no usual signal pattern is inferred.

Overview

30
Messages attributed
2
UTC dates decoded
7
Active 15-min windows
-12 dB
Estimated median S/N

Bands

20m · 30
First attributed message: 2026-06-11
Last attributed message: 2026-06-19 22:03 UTC

Observed FT8 message patterns

Attributed sample
30 messages
Active dates
2 UTC dates
Estimated median S/N
-12 dB
Estimated 10th-90th percentile
-19 to -3 dB
Recurring-pattern threshold
Not met

SO8OO display ranges among successful decodes: weak (≤ -16 dB) 8, moderate (-15 to -9 dB) 12, strong (≥ -8 dB) 10.

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 JR4FNW in decoded directed-looking exchanges:

Most frequent locator attributed to JR4FNW

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
PM64 · 16 decoded messages
SO8OO receiver locator
KN09VW
Locator-centre separation
8,453 km (approx.)
Last such locator decoded
2026-06-19 22:02 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 UTCBandJR4FNW S/NCounterpartCounterpart S/NMsgsCapture
08-28 20:47 40m - / -16 IR7MGGC -11 / - 3 Partial capture
08-28 19:36 40m - / -19 R7ZY +4 / - 3 Partial capture
08-01 19:07 20m - / -11 F4JHO -8 / - 2 ✓ Closing fragment
08-01 18:48 20m - / - IK5EEA -3 / - 6 Partial capture
07-31 18:51 20m - / -11 CT1ISH -3 / - 2 Partial capture
07-31 18:46 20m - / -18 OZ9FF -15 / - 2 ✓ Closing fragment
07-31 18:41 20m - / -7 RA4ABH -12 / - 3 ✓ Closing fragment
07-31 18:35 20m - / -10 US5HL +7 / - 2 ✓ Closing fragment
07-31 18:27 20m - / -13 R6SS +5 / - 3 ✓ Closing fragment
07-31 18:25 20m - / -4 IZ2ACM 0 / - 2 ✓ Closing fragment
07-31 18:18 20m - / - RM1F 0 / - 4 Partial capture
07-31 18:01 20m - / -9 LY3KX -22 / - 2 ✓ Closing fragment
07-31 17:51 20m - / -9 TA2ANK -15 / - 2 ✓ Closing fragment
07-31 17:33 20m - / -14 RU3DBT -13 / - 9 ✓ Closing fragment
07-31 17:27 20m - / -15 F4IVG -8 / - 2 ✓ Closing fragment
07-24 19:22 20m - / - SP1TJ +2 / - 2 ✓ Closing fragment
07-24 18:49 40m - / -17 UR5EDX +10 / - 4 ✓ Closing fragment
07-24 18:38 40m - / - DL3KVR -2 / - 2 Partial capture
07-24 18:26 40m - / - UR5EDX +8 / - 3 Partial capture
06-26 20:10 20m - / -12 IW2JYJ -5 / - 2 ✓ Closing fragment
06-26 19:56 20m - / -13 IZ2DPX +3 / - 2 ✓ Closing fragment
06-26 19:52 20m - / - EW8CW -13 / - 2 ✓ Closing fragment
06-26 19:42 20m - / -17 F5PGA -2 / - 5 Partial capture

Recent FT8 messages decoded at SO8OO

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

40m 
UTC    dB Audio  Message
183815  -1 2763  JR4FNW EU4U RR73
183815  -4 2849  JR4FNW DL3KVR JO64 (x2)
184900  +8  946  JR4FNW UR5EDX KN78 (x4)
193415  -2  837  JR4FNW TA3GO RR73
193615  +4 2604  JR4FNW R7ZY KN98 (x3)
194245 -24 1936  JR4FNW UA3SNB RR73
204730 -11 1738  JR4FNW IR7MGGC -16 (x3)
20m 
UTC    dB Audio  Message
184645 -16 2321  JR4FNW OZ9FF RR73
184730 -18 1133  JR4FNW IW9FRA JM68
185100  -4  864  JR4FNW CT1ISH -11 (x2)
183830  -8 2164  JR4FNW II3DRC -11
184715 -12 2454  JR4FNW OE6GBG RR73
184815  -1 1075  JR4FNW IK5EEA JN53
184845  -9  681  JR4FNW IW8BZE JN70
184845  -1 1075  JR4FNW IK5EEA JN53 (x5)
190700  -8  276  JR4FNW F4JHO -11 (x2)

FT8DB and SO8OO WebSDR are a hobby project maintained solo. ☕ Buy me a coffee