OK4SU — FT8 activity observed at SO8OO

DXCC entity inferred from callsign: Czech Republic Most frequent locator attributed to this token: JN89

Receiver-side FT8 activity involving OK4SU, decoded by SO8OO in southeastern Poland. 204 FT8 messages attributed to this token as transmitter, on 40m, 20m, 10m, across 14 UTC dates in the available aggregate history. Observed between 2026-06-10 and 2026-07-24.

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 204 FT8 messages attributed to OK4SU as the transmitting token by decoded message structure across 14 UTC dates in the available aggregate history. The largest monitored-band total was 20 m (57%), followed by 40 m (42%) and 10 m (1%). Most decodes (63%) fell within the six-hour window 06:00-12:00 UTC. Received S/N was mixed across SO8OO's weak, moderate and strong ranges; the estimated median was -12.5 dB.

Overview

204
Messages attributed
14
UTC dates decoded
41
Active 15-min windows
-12.5 dB
Estimated median S/N

Bands

40m · 85 20m · 117 10m · 2
First attributed message: 2026-06-10
Last attributed message: 2026-07-24 09:26 UTC

Observed FT8 message patterns

Attributed sample
204 messages
Active dates
14 UTC dates
Estimated median S/N
-12.5 dB
Estimated 10th-90th percentile
-22 to 0 dB
Recurring-pattern threshold
Met

SO8OO display ranges among successful decodes: weak (≤ -16 dB) 71, moderate (-15 to -9 dB) 62, strong (≥ -8 dB) 71.

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 OK4SU in decoded directed-looking exchanges:

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 OK4SU

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
JN89 · 59 decoded messages
SO8OO receiver locator
KN09VW
Locator-centre separation
348 km (approx.)
Last such locator decoded
2026-07-24 09:00 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 UTCBandOK4SU S/NCounterpartCounterpart S/NMsgsCapture
09-18 05:18 40m - / -15 RN6MA -10 / - 3 Partial capture
09-18 04:55 40m - / -11 UA4FKT +2 / - 5 Partial capture
09-18 04:54 40m - / - R6LE -2 / - 2 Partial capture
07-30 12:14 20m - / -13 R4IK -11 / - 2 ✓ Closing fragment
07-30 11:37 20m - / -1 R6LQU -22 / - 2 Partial capture
07-30 09:17 20m - / -23 PE9JAN -13 / - 3 ✓ Closing fragment
07-24 14:28 10m - / -18 PD1HBL -13 / - 2 Partial capture
07-24 09:27 20m - / - IK4LZH +7 / - 4 Partial capture
07-24 09:24 20m -2 / - GM3AND - / -14 4 Partial capture
07-24 08:59 20m -11 / - DF3IS - / +3 2 ✓ Closing fragment
07-24 08:52 20m - / - PD3LKN -18 / - 2 Partial capture
07-24 08:45 20m - / - IK4LZH -2 / - 3 Partial capture
07-24 08:40 20m -5 / - SQ8ECJ - / +2 2 ✓ Closing fragment
07-24 08:40 20m - / - 9A1CCS -6 / - 2 Partial capture
07-24 08:37 20m -2 / -16 DL3MIB -10 / -3 5 ✓ Full exchange observed
07-24 08:32 20m - / -14 9A4DK -5 / - 3 ✓ Closing fragment
07-24 06:41 40m -10 / - PD2MAC/P - / -28 2 ✓ Closing fragment
07-24 06:40 40m -19 / - F4AGZ - / -27 2 ✓ Closing fragment
07-24 06:36 40m -19 / - ND9M - / -2 3 Partial capture
07-23 13:53 20m - / -8 DJ1TU -15 / - 3 ✓ Closing fragment
07-23 13:53 20m - / - PD3LKN -14 / - 8 Partial capture
07-23 08:55 20m - / -5 TK5K -7 / - 2 ✓ Closing fragment
07-23 08:52 20m - / -7 SV5AZK -18 / - 3 ✓ Closing fragment
07-23 08:50 20m - / - PD7JLP 0 / - 2 ✓ Closing fragment
07-22 09:29 20m - / - DK7JL -21 / - 3 Partial capture
07-22 09:28 20m -1 / - YO6PPX -10 / 0 5 Partial capture
07-22 05:33 40m - / - UA4FKT -15 / - 2 Partial capture
07-21 14:26 40m -16 / - F4GVO - / -13 4 ✓ Closing fragment
07-21 14:23 40m -8 / - F1IQH - / -6 2 Partial capture
07-21 12:27 20m -8 / - UB3DQR - / -1 2 Partial capture
07-21 11:51 20m - / -18 PD3LKN -15 / - 7 Partial capture
07-21 11:02 20m - / - LZ1BT -17 / - 3 Partial capture
07-21 10:54 20m - / -19 F1PBZ -12 / - 2 Partial capture
07-21 07:48 20m - / +3 HG8LXL 0 / - 3 ✓ Closing fragment
07-21 07:48 20m - / - YO3IZI +3 / - 4 Partial capture
07-21 06:06 40m -18 / - YL2IV - / - 2 ✓ Closing fragment
07-21 06:05 40m - / - DL3MIB -12 / - 7 Partial capture
07-20 09:03 40m -22 / - OY1R - / -10 2 Partial capture
07-15 11:32 20m - / +2 DL6CGN -8 / - 2 ✓ Closing fragment
07-13 11:45 20m - / - PD2ARI -22 / - 3 Partial capture
07-10 08:41 40m -10 / - IW3HCN - / +6 2 ✓ Closing fragment
07-09 08:28 40m -16 / - <...> - / -20 2 ✓ Closing fragment
07-09 08:11 40m -16 / - MW3FLI - / +6 2 Partial capture
07-09 05:32 20m - / -2 RX3ASQ -5 / - 2 ✓ Closing fragment
07-08 07:47 40m - / -11 US1MM -17 / - 4 ✓ Closing fragment
07-08 07:31 40m -20 / - DB1AA - / +6 2 ✓ Closing fragment
07-08 07:23 40m -22 / -19 IK4LZH -8 / +2 2 Partial capture
07-08 07:10 40m -16 / - GJ0KYZ - / -14 4 Partial capture
07-08 07:09 40m -20 / - M0ELS - / -6 2 Partial capture
07-08 07:01 40m -15 / - KC2YYF - / -29 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
064030 -14 1649  F4AGZ OK4SU -27
064100 -10  355  PD2MAC/P OK4SU -28
064100 -24 1649  F4AGZ OK4SU RR73
064230  -9  356  PD2MAC/P OK4SU RR73
045415  -4 2114  OK4SU R6LE LN07 (x2)
045515  +2 1083  OK4SU UA4FKT LO23 (x5)
051815  -4 1085  OK4SU RN6MA -15 (x3)
052245  +0 1084  OK4SU PD1HBL R-21
20m 
UTC    dB Audio  Message
092445  +5  788  GM3AND OK4SU -14 (x3)
092715 +13  464  OK4SU IK4LZH JN54 (x4)
091715  -9 2522  OK4SU PE9JAN JO22 (x3)
113700 -22 1338  OK4SU R6LQU KN97 (x2)
120945  -4 2839  OK4SU M0KZC/P 73
121400  -9 1337  OK4SU R4IK -13 (x2)
10m 
UTC    dB Audio  Message
093745 -11 1491  OK4SU DL5ALF JN48 (x4)
093915 -23 1297  CQ OK4SU JN89                         a1
093930 -17 1469  OK4SU ON1JP -10 (x6)
094600  -3 1328  OK4SU F4VTR R-10 (x2)
142830 -11 1305  OK4SU PD1HBL R-18 (x2)

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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