S51UN — FT8 activity observed at SO8OO

DXCC entity inferred from callsign: Slovenia Most frequent locator attributed to this token: JN75

Receiver-side FT8 activity involving S51UN, decoded by SO8OO in southeastern Poland. 2,321 FT8 messages attributed to this token as transmitter, on 40m, 20m, 10m, across 78 UTC dates in the available aggregate history. Observed between 2026-06-07 and 2026-09-13.

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 2,321 FT8 messages attributed to S51UN as the transmitting token by decoded message structure across 78 UTC dates in the available aggregate history. The largest monitored-band total was 40 m (81%), followed by 20 m (16%) and 10 m (4%). Most decodes (81%) fell within the six-hour window 16:00-22:00 UTC. Received S/N was mixed across SO8OO's weak, moderate and strong ranges; the estimated median was -7.1 dB.

Overview

2,321

Messages attributed

UTC dates decoded

382

Active 15-min windows

-7.1 dB

Estimated median S/N

Bands

40m · 1,871 20m · 368 10m · 82

First attributed message: 2026-06-07
Last attributed message: 2026-09-13 20:02 UTC

Observed FT8 message patterns

Attributed sample: 2,321 messages
Active dates: 78 UTC dates
Estimated median S/N: -7.1 dB
Estimated 10th-90th percentile: -16 to +2 dB
Recurring-pattern threshold: Met

SO8OO display ranges among successful decodes: weak (≤ -16 dB) 303, moderate (-15 to -9 dB) 751, strong (≥ -8 dB) 1,267.

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 S51UN in decoded directed-looking exchanges:

R3HX · European Russia ×3 R2DX · European Russia ×2 5Z4VJ · Kenya ×2 DL9KM · Fed. Rep. of Germany ×2 R1QF · European Russia ×2 R6DZR · European Russia ×2 TN8GD · Republic of the Congo ×2 UB1OBV · European Russia ×2 UB3AYQ · European Russia ×2 R3YAR · European Russia ×2 R4DB · European Russia ×2 RA3VLR · European Russia ×2

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 S51UN

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: JN75 · 1,391 decoded messages
SO8OO receiver locator: KN09VW
Locator-centre separation: 708 km (approx.)
Last such locator decoded: 2026-09-13 19:59 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 UTC	Band	S51UN S/N	Counterpart	Counterpart S/N	Msgs	Capture
09-13 20:02	40m	+4 / -17	CT2HEX	-7 / -13	5	Partial capture
09-13 19:59	40m	+3 / -	R8OAE	- / -13	5	✓ Closing fragment
09-13 19:50	40m	-1 / -	RA0AB	- / -20	6	✓ Closing fragment
09-13 19:35	40m	-1 / -	R4HOH	- / -	2	Partial capture
09-13 19:19	40m	-7 / -	UA6XDA	- / -16	2	Partial capture
09-13 19:15	40m	-1 / -	RA0AB	- / -	2	Partial capture
09-12 20:42	40m	+5 / -	4X5GE	- / -11	3	✓ Closing fragment
09-12 20:30	40m	+3 / -	JJ2IJU	- / -	3	Partial capture
09-12 19:30	40m	-5 / -	RA0AB	- / -	2	Partial capture
09-11 21:28	40m	-6 / -	R9FDL	- / -13	3	Partial capture
09-11 21:18	40m	-4 / -	R9FDL	- / -	2	Partial capture
09-11 21:04	40m	-4 / -	RC2GB	- / -15	2	✓ Closing fragment
09-11 20:43	40m	-8 / -15	UB6LUR	+1 / -5	3	✓ Full exchange observed
09-11 20:40	40m	-5 / -3	RD6OB	0 / -4	5	✓ Full exchange observed
09-11 20:36	40m	-5 / -	HL3KPJ	- / -12	3	✓ Closing fragment
09-11 20:27	40m	-4 / -14	UB6LUR	-3 / -	3	Partial capture
09-11 20:24	40m	-4 / -	RA1NBG	- / -7	3	✓ Closing fragment
09-11 20:22	40m	-4 / -	F4NJU/P	- / -13	3	Partial capture
09-11 20:20	40m	-2 / -	R6ZS	-10 / -11	3	✓ Closing observed
09-08 21:44	40m	+2 / -	R9CA	-14 / -10	3	✓ Closing observed
09-08 21:40	40m	-2 / -	BD8FWI	- / -	3	Partial capture
09-08 21:38	40m	-4 / -	N1NRL	- / -	3	Partial capture
09-08 21:36	40m	-8 / -	PY2IQ	- / -	3	Partial capture
09-08 21:31	40m	-7 / -	JY5IB	-18 / -	4	✓ Closing observed
09-08 21:28	40m	-5 / -	VE2KTF	- / -	3	Partial capture
09-08 21:25	40m	-10 / -	VK6NWF	- / -	3	Partial capture
09-08 21:24	40m	0 / -	OH6B	- / -9	3	✓ Closing fragment
09-08 21:22	40m	-14 / -	VE2KTF	- / -	3	Partial capture
09-08 21:01	40m	- / -	R4FBT	-4 / -	3	✓ Closing fragment
09-08 20:56	40m	- / -9	RA3GDV	+9 / -	2	✓ Closing fragment
09-08 20:48	40m	- / -17	R4FBT	-3 / -	20	Partial capture
09-07 21:29	40m	-2 / -	VK3JMA	- / -	2	Partial capture
09-07 21:25	40m	+3 / -	7Z1TT	- / -	2	Partial capture
09-07 21:07	40m	-3 / -	RK4FV	- / -17	4	Partial capture
09-07 21:04	40m	0 / -	UN8DAW	- / -16	4	✓ Closing fragment
09-07 20:59	40m	-4 / -16	A61FJ	-22 / -11	7	✓ Full exchange observed
09-06 21:16	40m	0 / -	R3MDA	- / -8	3	✓ Closing fragment
09-06 20:53	40m	+4 / -	R1BPW	- / -6	2	✓ Closing fragment
09-06 20:49	40m	-5 / -2	RG6ZF	-13 / -1	5	✓ Full exchange observed
09-06 20:47	40m	+2 / -	CN8NS	- / -	2	Partial capture
09-06 20:35	40m	-3 / -10	R3KIZ	-12 / -3	5	✓ Full exchange observed
09-06 20:32	40m	-3 / +3	4O7CC	-10 / -3	4	✓ Full exchange observed
09-06 20:28	40m	-4 / -	RD0L	- / -	2	Partial capture
09-06 20:02	40m	- / -1	LZ1DPP	-6 / -	2	✓ Closing fragment
09-06 19:52	40m	+4 / -	RX3DTN	- / -18	2	✓ Closing fragment
09-06 19:47	40m	0 / -6	R73SLET	-4 / -7	3	Partial capture
09-06 19:34	40m	-2 / -	RT1L	-1 / -	2	✓ Closing observed
09-06 19:28	40m	-6 / -	JH5AVM	- / -	2	Partial capture
09-06 19:23	40m	-1 / -	9H4JX	- / -8	3	✓ Closing fragment
09-06 19:22	40m	-2 / -4	RK3YWA	-12 / -9	5	✓ Full exchange observed

Recent FT8 messages decoded at SO8OO

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

40m

UTC    dB Audio  Message
195045  -3 1235  RA0AB S51UN JN75 (x5)
195915  +6  919  R8OAE S51UN JN75 (x5)
200200  -7  680  S51UN CT2HEX IM58
200215  +2  919  CT2HEX S51UN -13
200230  -5  680  S51UN CT2HEX R-17
200245  +5  919  CT2HEX S51UN -13
200300  -9  680  S51UN CT2HEX R-17

20m

UTC    dB Audio  Message
151615  +2 1973  S51UN F5PBG -02
152415  -2 2371  S51UN F6IJT -23 (x4)
154345  +3 1239  S51UN RA6FSV -16 (x2)
160545  -6 2021  S51UN RN6LDK RR73
161915  +2 2364  S51UN MW7KFZ -15
162615  +1  919  S51UN EA4GA -10
180200  +8  408  S51UN LZ1WV -11 (x5)

10m

UTC    dB Audio  Message
130900  +5 1863  S51UN UR4QWW KN77 (x3)
191445 -19 1777  EA8UP S51UN JN75
134345 -21 1980  RV3AMV S51UN 73
134545 -21 1980  DH2DAM S51UN RRR
134715 -20 1980  DL0FTT S51UN RRR
135145 -18 1722  RW3XB S51UN JN75 (x5)
095915 -17 2022  R5MA S51UN JN75 (x3)

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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