W4MRK — FT8 activity observed at SO8OO

DXCC entity inferred from callsign: United States Most frequent locator attributed to this token: FM18

Receiver-side FT8 activity involving W4MRK, decoded by SO8OO in southeastern Poland. 25 FT8 messages attributed to this token as transmitter, on 80m, 40m, 20m, across 6 UTC dates in the available aggregate history. Observed between 2026-08-13 and 2026-08-28.

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 25 FT8 messages attributed to W4MRK 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 (88%), followed by 80 m (8%) and 40 m (4%). Most decodes (100%) fell within the six-hour window 00:00-06:00 UTC. Received S/N was mixed across SO8OO's weak, moderate and strong ranges; the estimated median was -13 dB.

Overview

25
Messages attributed
6
UTC dates decoded
9
Active 15-min windows
-13 dB
Estimated median S/N

Bands

First attributed message: 2026-08-13
Last attributed message: 2026-08-28 05:24 UTC

Observed FT8 message patterns

Attributed sample
25 messages
Active dates
6 UTC dates
Estimated median S/N
-13 dB
Estimated 10th-90th percentile
-22 to -4 dB
Recurring-pattern threshold
Met

SO8OO display ranges among successful decodes: weak (≤ -16 dB) 10, moderate (-15 to -9 dB) 11, strong (≥ -8 dB) 4.

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.

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 W4MRK

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
FM18 · 8 decoded messages
SO8OO receiver locator
KN09VW
Locator-centre separation
7,390 km (approx.)
Last such locator decoded
2026-08-28 04:41 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 UTCBandW4MRK S/NCounterpartCounterpart S/NMsgsCapture
08-29 04:55 40m - / - PE1NMM -17 / - 3 Partial capture
08-29 04:53 40m - / -5 ON1JP -15 / - 4 Partial capture
08-29 04:52 40m - / - IK6DLK -8 / - 2 ✓ Closing fragment
08-29 04:45 40m - / -13 F5MOO 0 / - 3 ✓ Closing fragment
08-29 04:42 40m - / -12 DL3MIB +10 / - 6 ✓ Closing fragment
08-29 04:42 40m - / -19 EA3IZF -15 / - 2 ✓ Closing fragment
08-29 04:37 40m - / -14 DL3OCF -6 / - 2 ✓ Closing fragment
08-29 04:31 40m - / -16 YO9IAB +12 / - 2 ✓ Closing fragment
08-28 04:41 20m -4 / +3 4L7T -12 / -21 7 ✓ Full exchange observed
08-28 04:39 20m -16 / - 9A5E - / -4 2 Partial capture
08-27 02:33 40m - / -15 EI2IXB -10 / - 2 ✓ Closing fragment
08-26 01:37 20m -7 / - KT4ZG - / - 2 Partial capture
08-26 01:14 20m -10 / - UT7UJ - / -18 2 Partial capture
08-26 01:11 20m -11 / - 9A2TN - / -15 4 ✓ Closing fragment
08-24 05:37 20m - / -15 IC8TEM +5 / - 3 ✓ Closing fragment
08-24 05:36 20m - / +2 HC2GRC -12 / - 2 ✓ Closing fragment
08-24 05:33 20m - / -15 LZ3BS +8 / - 2 ✓ Closing fragment
08-23 00:47 20m -20 / - K7LNY - / -12 2 Partial capture
08-22 01:21 20m - / - 7Z1DM -3 / - 4 ✓ Closing fragment
08-20 04:12 20m - / -13 TJ1GD 0 / - 2 ✓ Closing fragment
08-20 04:04 20m - / -24 UN6LN -19 / - 2 ✓ Closing fragment
08-20 03:54 40m - / +2 HB9CXZ -14 / - 2 ✓ Closing fragment
08-20 03:48 80m - / - DK5WL -18 / - 3 Partial capture
08-20 03:48 80m - / -7 DK7ZT -10 / - 5 Partial capture
08-20 02:41 80m - / - DC6KW -16 / - 4 Partial capture
08-20 00:41 40m - / -18 EB3JT -13 / - 3 ✓ Closing fragment
08-20 00:35 40m - / -16 MM0KQC -17 / - 7 Partial capture
08-20 00:02 40m - / -6 OS4K -19 / - 3 Partial capture
08-19 23:52 40m - / -12 DK7ZT -15 / - 3 Partial capture
08-19 23:49 40m - / - IU5HIU -8 / - 2 Partial capture
08-18 03:07 80m - / - DL4ME +9 / - 3 Partial capture
08-18 03:07 80m - / -17 GB8VJ -22 / - 2 Partial capture
08-18 03:07 80m - / - OM0RX -6 / - 4 Partial capture
08-15 02:14 20m - / - IZ3EAW -8 / - 3 Partial capture
08-14 02:45 80m - / - W3DQS -16 / - 2 ✓ Closing fragment
08-14 02:21 80m - / -21 DK7ZT +2 / - 5 Partial capture
08-14 01:32 80m - / -17 DK7ZT +4 / - 2 Partial capture
08-13 03:47 80m - / - DO1ID +19 / - 2 Partial capture
08-13 03:46 80m - / - DO8JB -6 / - 11 Partial capture
08-13 03:40 80m - / - 9A4ZM +12 / - 3 Partial capture
08-13 03:37 80m - / -4 PI4DX 0 / - 2 ✓ Closing fragment
08-07 03:54 20m - / - UR4QFP 0 / - 2 Partial capture
08-07 03:48 20m - / -12 4X1UF -12 / - 2 ✓ Closing fragment
08-06 02:54 20m - / - HB9TIH -18 / - 2 Partial capture
07-25 05:27 20m - / -15 4Z1RZ -6 / - 2 Partial capture
07-25 05:26 20m - / - OD5KU -3 / - 3 Partial capture
07-25 04:33 20m - / -13 T77BL -4 / - 2 ✓ Closing fragment
07-25 04:29 20m - / -1 LX1TI +1 / - 2 ✓ Closing fragment
07-25 04:26 20m - / -14 UR9QQ -12 / - 6 ✓ Closing fragment
07-25 04:14 20m - / -14 R2GF -4 / - 2 Partial capture

Recent FT8 messages decoded at SO8OO

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

80m
UTC    dB Audio  Message
030845  -5 1504  W4MRK OM0RX JN88
024100 -19 1834  W4MRK DC6KW JO30 (x4)
034800  -7 1894  W4MRK DK7ZT -07
034800 -16 1515  W4MRK DK5WL JN39
034830 -11 1894  W4MRK DK7ZT -07
034830 -20 1516  W4MRK DK5WL JN39
034900 -13 1893  W4MRK DK7ZT -07
034900 -19 1515  W4MRK DK5WL JN39
034930 -11 1893  W4MRK DK7ZT -07 (x2)
024315  +8 1914  W4MRK DK5WL JN39
024445  -9 1316  W4MRK GM6URC -17
40m
UTC    dB Audio  Message
044445 +10 1009  W4MRK DL3MIB 73
044515  -1 1977  W4MRK F5MOO JN07 (x3)
044645 -13  310  W4MRK EA2XX R-17
044745  +0  890  W4MRK DD7EE JO41
045215 -11 2148  W4MRK IK6DLK JN63
045315 -14 1059  W4MRK ON1JP -05
045315  -4 2148  W4MRK IK6DLK 73
045345 -13 1059  W4MRK ON1JP -05 (x3)
045530  -9 1646  W4MRK PE1NMM JO32 (x3)
20m
UTC    dB Audio  Message
013700 -10  365  KT4ZG W4MRK FM18 (x2)
013830 -21 1143  WS7M W4MRK R-12
043945 -15 2209  9A5E W4MRK FM18 (x2)
044100 -16  310  W4MRK 4L7T +03
044115  -3  312  4L7T W4MRK FM18
044130 -10  310  W4MRK 4L7T -04 (x2)
044215  -6  312  4L7T W4MRK R-21
044230 -11  311  W4MRK 4L7T RR73
044245  -4  311  4L7T W4MRK 73
050200 -17 2017  W4MRK YL2KF -18
050400  -3 2018  W4MRK R7BN LN05
052430 -14 2667  ES6DO W4MRK 73

Decoder S/N history by band

Count-weighted daily averages across messages attributed to this profiled token and successfully decoded at SO8OO, limited to the rolling 90-day UTC chart window.

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