JH4MGU — FT8 activity observed at SO8OO

DXCC entity inferred from callsign: Japan Most frequent locator attributed to this token: PM75

Receiver-side FT8 activity involving JH4MGU, decoded by SO8OO in southeastern Poland. 175 FT8 messages attributed to this token as transmitter, on 40m, 20m, across 1 UTC dates in the available aggregate history. Last observed 2026-08-23.

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 175 FT8 messages attributed to JH4MGU 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 (94%), followed by 40 m (6%). In this small sample, the estimated median decoder S/N was -5 dB; no usual signal pattern is inferred.

Overview

175
Messages attributed
1
UTC dates decoded
13
Active 15-min windows
-5 dB
Estimated median S/N

Bands

First attributed message: 2026-08-23
Last attributed message: 2026-08-23 23:02 UTC

Observed FT8 message patterns

Attributed sample
175 messages
Active dates
1 UTC dates
Estimated median S/N
-5 dB
Estimated 10th-90th percentile
-12 to -1 dB
Recurring-pattern threshold
Not met

SO8OO display ranges among successful decodes: weak (≤ -16 dB) 8, moderate (-15 to -9 dB) 29, strong (≥ -8 dB) 138.

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).

Attributed messages by UTC hour

Rolling 90-day UTC chart window. Counts follow decoded message structure: the first token for CQ, or the second token in a directed-looking message.

Most frequent locator attributed to JH4MGU

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
PM75 · 76 decoded messages
SO8OO receiver locator
KN09VW
Locator-centre separation
8,477 km (approx.)
Last such locator decoded
2026-08-23 23:02 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 UTCBandJH4MGU S/NCounterpartCounterpart S/NMsgsCapture
09-02 22:00 40m - / -15 DL3MIB +4 / - 3 ✓ Closing fragment
09-02 21:58 40m - / -17 IZ8XME 0 / - 3 ✓ Closing fragment
09-02 08:02 10m - / -2 EA3AKY -10 / - 2 ✓ Closing fragment
09-02 07:55 10m - / -21 LZ2II -9 / - 5 Partial capture
08-27 05:53 20m - / -18 XQ1KK -11 / - 2 ✓ Closing fragment
08-24 11:18 10m - / -6 G4XEE -18 / - 3 ✓ Closing fragment
08-23 22:59 20m -10 / - BI3AAJ/P - / - 5 Partial capture
08-23 22:51 20m -14 / -23 R2DN +3 / - 7 ✓ Closing observed
08-23 22:47 20m - / +1 4Z5AY +6 / - 2 ✓ Closing fragment
08-23 22:42 20m -4 / - LZ2EW - / -19 2 ✓ Closing fragment
08-23 22:41 20m -6 / - DC9YH - / -17 2 ✓ Closing fragment
08-23 22:38 20m -2 / - DC3LD - / -16 2 ✓ Closing fragment
08-23 22:35 20m -4 / - M9TAM - / -16 3 ✓ Closing fragment
08-23 22:33 20m -3 / - CT1BFP - / - 5 Partial capture
08-23 22:31 20m -5 / - PF26GP - / - 3 Partial capture
08-23 22:29 20m -6 / - BD7PWV - / -16 2 ✓ Closing fragment
08-23 22:27 20m -5 / - HG0NPJ - / -13 3 ✓ Closing fragment
08-23 22:26 20m -4 / +2 OD5ZZ -9 / -9 4 ✓ Full exchange observed
08-23 22:23 20m -7 / - G0ORC - / -19 3 ✓ Closing fragment
08-23 22:19 20m -5 / - YT1DDL - / -22 2 ✓ Closing fragment
08-23 22:17 20m -6 / - DL2AX - / -11 2 ✓ Closing fragment
08-23 22:14 20m -4 / - DG6VC - / -18 2 ✓ Closing fragment
08-23 22:13 20m -10 / - RL6MT -2 / -23 7 Partial capture
08-23 22:07 20m -8 / - SP7NC - / -16 2 ✓ Closing fragment
08-23 22:06 20m -6 / - BD8ENX -18 / -13 4 ✓ Closing observed
08-23 22:04 20m -3 / - SP7AAO - / -16 2 ✓ Closing fragment
08-23 22:02 20m -7 / - TA3ZZ -14 / -22 5 ✓ Closing observed
08-23 21:59 20m -8 / - DL8HXP - / -7 2 ✓ Closing fragment
08-23 21:58 20m -2 / - BH8NNU - / -20 2 ✓ Closing fragment
08-23 21:56 20m -5 / - SQ5EXI - / -9 3 ✓ Closing fragment
08-23 21:54 20m -2 / -15 IU5HIU +4 / -13 5 ✓ Full exchange observed
08-23 21:53 20m -2 / - EA3AAY - / -14 2 ✓ Closing fragment
08-23 21:52 20m - / - IU5HIU -3 / - 2 Partial capture
08-23 21:50 20m 0 / - 2E0BTX - / -19 4 ✓ Closing fragment
08-23 21:50 20m -2 / -12 I6GFX 0 / -16 10 ✓ Full exchange observed
08-23 21:49 20m -1 / - BH8NNU - / -20 2 Partial capture
08-23 21:46 20m -2 / - SV1DZB -14 / -7 3 ✓ Closing observed
08-23 21:45 20m -2 / - SP3SXU - / -16 2 ✓ Closing fragment
08-23 21:44 20m -2 / -17 IW5ABF -1 / -17 6 ✓ Full exchange observed
08-23 21:42 20m -3 / - BH4ECL - / -9 2 ✓ Closing fragment
08-23 21:41 20m -4 / - RA6OF - / -13 2 ✓ Closing fragment
08-23 21:39 20m -5 / - F5RAV - / -13 4 ✓ Closing fragment
08-23 21:38 20m -5 / - OH4LRP - / -16 2 ✓ Closing fragment
08-23 21:35 20m -1 / - JA9CYD - / -16 2 Partial capture
08-23 21:34 20m -2 / - R7ZY - / -16 2 Partial capture
08-23 21:33 20m -2 / -9 A92AE -9 / -9 3 ✓ Full exchange observed
08-23 21:16 20m - / - DG6VC -10 / - 10 Partial capture
08-23 21:13 20m -3 / - DL1UDO - / -15 6 ✓ Closing fragment
08-23 21:11 20m -8 / -18 EC5CFV -13 / - 2 ✓ Closing observed
08-23 20:21 40m -10 / - IU2OQT -2 / -13 3 Partial capture

Recent FT8 messages decoded at SO8OO

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

40m
UTC    dB Audio  Message
201930  -9 1688  JH4MGU SV1DKR R-08
201945 -11 2820  SV1DKR JH4MGU -17 (x2)
202045 -10 2820  CQ JH4MGU PM75
202100 +12 2820  JH4MGU RY3F -11 (x2)
202130  +1  797  JH4MGU IU2OQT JN45 (x2)
202215 -10 2820  IU2OQT JH4MGU -13
215845  -2 1616  JH4MGU IZ8XME -17 (x3)
220015  +3 1069  JH4MGU DL3MIB JN57 (x3)
10m
UTC    dB Audio  Message
111000 -21 1370  JH4MGU G4PMZ -14
111800 -18 1531  JH4MGU G4XEE -06 (x3)
075545  -8 1690  JH4MGU LZ2II -21 (x5)
080245 -10  719  JH4MGU EA3AKY -02 (x2)
20m
UTC    dB Audio  Message
225300  +5 2424  JH4MGU R2DN KO95
225315 -15 2424  BI3AAJ/P JH4MGU 73
225330  +1 2424  JH4MGU R2DN KO95 (x2)
225415 -14 2424  R2DN JH4MGU RR73
225430  +1 2425  JH4MGU R2DN 73
225500 -19 1782  JH4MGU SV2TCC R-15
225845 -11 2424  R0SBH JH4MGU -19
225945 -13 2424  BI3AAJ/P JH4MGU PM75 (x5)
055330 -13 1043  JH4MGU XQ1KK -18 (x2)

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