YU4HAK — FT8 activity observed at SO8OO

DXCC entity inferred from callsign: Serbia Most frequent locator attributed to this token: KN04

Receiver-side FT8 activity involving YU4HAK, decoded by SO8OO in southeastern Poland. 9 FT8 messages attributed to this token as transmitter, on 20m, across 2 UTC dates in the available aggregate history. Observed between 2026-06-20 and 2026-07-04.

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 9 FT8 messages attributed to YU4HAK 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 -16 dB; no usual signal pattern is inferred.

Overview

9
Messages attributed
2
UTC dates decoded
5
Active 15-min windows
-16 dB
Estimated median S/N

Bands

20m · 9
First attributed message: 2026-06-20
Last attributed message: 2026-07-04 17:59 UTC

Observed FT8 message patterns

Attributed sample
9 messages
Active dates
2 UTC dates
Estimated median S/N
-16 dB
S/N percentile sample
Too small
Recurring-pattern threshold
Not met

SO8OO display ranges among successful decodes: weak (≤ -16 dB) 5, moderate (-15 to -9 dB) 4, strong (≥ -8 dB) 0.

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 YU4HAK in decoded directed-looking exchanges:

Most frequent locator attributed to YU4HAK

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
KN04 · 7 decoded messages
SO8OO receiver locator
KN09VW
Locator-centre separation
608 km (approx.)
Last such locator decoded
2026-07-04 17:59 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 UTCBandYU4HAK S/NCounterpartCounterpart S/NMsgsCapture
09-12 11:43 40m - / -11 SQ9AWN -12 / - 3 ✓ Closing fragment
09-12 11:23 40m - / -2 SQ9AWN -8 / - 6 Partial capture
09-12 11:14 40m - / -3 SP9CXN +2 / - 2 ✓ Closing fragment
09-12 11:09 40m - / -1 SP9CXN +1 / - 2 Partial capture
09-12 11:00 40m - / -19 OK1MDK -4 / - 4 ✓ Closing fragment
09-12 10:55 40m - / +4 HA0AA -8 / - 2 ✓ Closing fragment
09-11 17:49 40m - / -14 ON4AOI +20 / - 2 ✓ Closing fragment
09-11 16:17 40m - / -19 IU7VOL -11 / - 3 ✓ Closing fragment
09-11 16:15 40m - / -9 SQ2GXO +23 / - 2 ✓ Closing fragment
07-17 15:18 20m - / -19 PB0ACU -8 / - 2 ✓ Closing fragment
07-04 17:59 20m -16 / - OZ4MT - / - 2 Partial capture
06-27 10:08 20m - / -23 E75AA -2 / - 2 ✓ Closing fragment
06-26 22:15 40m - / -21 ER1CW -15 / - 2 ✓ Closing fragment
06-26 22:03 40m - / -19 9A5MTV -23 / - 2 Partial capture
06-26 21:59 20m - / -14 G0TIX -6 / - 2 Partial capture

Recent FT8 messages decoded at SO8OO

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

40m 
UTC    dB Audio  Message
110215  -9 1695  YU4HAK OK1MDK RR73
110730 -13 1038  YU4HAK HA7AV -09
110930  +2 2025  YU4HAK SP9CXN -01 (x4)
112345  -4 1537  YU4HAK SQ9AWN -02 (x9)
20m 
UTC    dB Audio  Message
215930  -6  777  YU4HAK G0TIX -14 (x2)
100845  -3 2750  YU4HAK E75AA -23 (x2)
173600 -10 1599  YU4HAK DL5FLN RR73
175900 -16 2431  OZ4MT YU4HAK KN04 (x2)
151815  -9  807  YU4HAK PB0ACU -19 (x2)
101400 -12  323  YU4HAK ON3URT -13

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