I5SFU — FT8 activity observed at SO8OO

DXCC entity inferred from callsign: Italy Most frequent locator attributed to this token: JN53

Receiver-side FT8 activity involving I5SFU, decoded by SO8OO in southeastern Poland. 31 FT8 messages attributed to this token as transmitter, on 40m, 20m, across 9 UTC dates in the available aggregate history. Observed between 2026-06-06 and 2026-09-19.

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 31 FT8 messages attributed to I5SFU as the transmitting token by decoded message structure across 9 UTC dates in the available aggregate history. The largest monitored-band total was 40 m (97%), followed by 20 m (3%). Most decodes (100%) fell within the six-hour window 15:00-21:00 UTC. Most successfully decoded messages attributed to this token fell in SO8OO's moderate S/N range (65%); the estimated median was -11 dB.

Overview

Messages attributed

UTC dates decoded

Active 15-min windows

-11 dB

Estimated median S/N

Bands

40m · 30 20m · 1

First attributed message: 2026-06-06
Last attributed message: 2026-09-19 16:04 UTC

Observed FT8 message patterns

Attributed sample: 31 messages
Active dates: 9 UTC dates
Estimated median S/N: -11 dB
Estimated 10th-90th percentile: -15 to -5 dB
Recurring-pattern threshold: Met

SO8OO display ranges among successful decodes: weak (≤ -16 dB) 1, moderate (-15 to -9 dB) 20, strong (≥ -8 dB) 10.

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 I5SFU in decoded directed-looking exchanges:

DB6LL/P · Fed. Rep. of Germany F5RRS · France IK4POB · Italy

Most frequent locator attributed to I5SFU

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: JN53 · 13 decoded messages
SO8OO receiver locator: KN09VW
Locator-centre separation: 1,089 km (approx.)
Last such locator decoded: 2026-09-19 16:03 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	I5SFU S/N	Counterpart	Counterpart S/N	Msgs	Capture
09-19 16:03	40m	-8 / -	UB3ADO/P	- / -8	2	Partial capture
09-19 15:56	40m	-12 / -	3Z100PKP	- / -6	2	Partial capture
09-07 16:25	40m	- / -3	IK4POB	-7 / -	3	✓ Closing fragment
09-07 16:17	40m	-12 / -	YO2LFP	- / -9	2	Partial capture
09-07 16:10	40m	-15 / -	DK3WL	- / +1	2	Partial capture
09-07 16:06	40m	- / -	DK3WL	-2 / -	2	Partial capture
09-05 16:42	40m	-13 / -6	DB6LL/P	+3 / -	3	✓ Closing observed
08-16 15:51	40m	- / -7	F5RRS	-9 / -	2	✓ Closing fragment

Recent FT8 messages decoded at SO8OO

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

40m

UTC    dB Audio  Message
160630  -2 2543  I5SFU DK3WL JO50 (x2)
161015 -15 1104  DK3WL I5SFU +01 (x2)
161300  -4  857  I5SFU HF100PKP -03
161715 -12  939  YO2LFP I5SFU R-09 (x2)
162530  -6  938  I5SFU IK4POB -03 (x3)
162700 -14 1377  I5SFU DH1KJ JN48
155645 -11  305  3Z100PKP I5SFU R-06 (x2)
160345  -7  438  UB3ADO/P I5SFU JN53 (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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