JA5SLV — FT8 activity observed at SO8OO

DXCC entity inferred from callsign: Japan Most frequent locator attributed to this token: PM74

Receiver-side FT8 activity involving JA5SLV, decoded by SO8OO in southeastern Poland. 54 FT8 messages attributed to this token as transmitter, on 20m, across 5 UTC dates in the available aggregate history. Observed between 2026-06-06 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 54 FT8 messages attributed to JA5SLV as the transmitting token by decoded message structure across 5 UTC dates in the available aggregate history. The largest monitored-band total was 20 m (100%). Most decodes (98%) fell within the six-hour window 15:00-21:00 UTC. Received S/N was mixed across SO8OO's weak, moderate and strong ranges; the estimated median was -9 dB.

Overview

54
Messages attributed
5
UTC dates decoded
11
Active 15-min windows
-9 dB
Estimated median S/N

Bands

20m · 54
First attributed message: 2026-06-06
Last attributed message: 2026-08-28 16:19 UTC

Observed FT8 message patterns

Attributed sample
54 messages
Active dates
5 UTC dates
Estimated median S/N
-9 dB
Estimated 10th-90th percentile
-13 to -6 dB
Recurring-pattern threshold
Met

SO8OO display ranges among successful decodes: weak (≤ -16 dB) 0, moderate (-15 to -9 dB) 29, strong (≥ -8 dB) 25.

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 JA5SLV 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 JA5SLV

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
PM74 · 22 decoded messages
SO8OO receiver locator
KN09VW
Locator-centre separation
8,565 km (approx.)
Last such locator decoded
2026-08-28 16:19 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 UTCBandJA5SLV S/NCounterpartCounterpart S/NMsgsCapture
08-27 17:01 20m - / -25 DK9NP +14 / - 2 ✓ Closing fragment
08-27 16:26 20m - / - G5JCC -11 / - 5 Partial capture
08-27 16:23 20m - / - DF7HG -2 / - 2 Partial capture
08-27 16:22 20m - / - G5JCC -11 / - 3 Partial capture
08-27 16:08 20m - / -14 SV9/PD9VOG +17 / - 2 Partial capture
08-27 16:01 20m - / - EA5AI -6 / - 2 Partial capture
08-27 15:57 20m -11 / - OK2WN - / -9 2 ✓ Closing fragment
08-27 15:51 20m -8 / - R9FFT -20 / - 2 ✓ Closing observed
08-27 15:49 20m -8 / - UR4UM - / -15 2 ✓ Closing fragment
08-27 15:47 20m -6 / - R2BMP - / -19 3 ✓ Closing fragment
08-27 15:45 20m -6 / - HA0NDN - / -15 2 ✓ Closing fragment
08-27 15:44 20m -8 / -15 RU3GF -5 / -8 4 ✓ Full exchange observed
08-27 15:38 20m -7 / - F6EKI +20 / -18 7 ✓ Closing observed
08-26 16:42 20m - / -24 ON4DS +14 / - 2 ✓ Closing fragment
08-26 16:37 20m - / -15 G3VCQ +7 / - 2 ✓ Closing fragment
08-26 16:01 20m - / -7 EX7DY -10 / - 2 ✓ Closing fragment
08-25 16:55 20m - / -12 F8FUA +18 / - 2 ✓ Closing fragment
08-22 16:40 20m - / -14 G4FAL +4 / - 2 ✓ Closing fragment
08-22 16:27 20m - / -17 F1POK -13 / - 3 ✓ Closing fragment
08-20 16:53 20m -10 / -9 F4JVF +13 / -11 4 ✓ Full exchange observed
08-20 16:45 20m - / -13 DF1IH +6 / - 3 ✓ Closing fragment
08-19 16:53 20m - / - F1THK -4 / - 2 ✓ Closing fragment
08-16 21:43 20m - / -18 EI9IB -10 / - 2 ✓ Closing fragment
08-14 16:51 20m - / - ON4IQ -10 / - 2 Partial capture
08-12 15:47 20m - / -9 R3KCW -3 / - 4 ✓ Closing fragment
08-07 16:42 20m - / - ON7NQ -8 / - 6 Partial capture
08-07 16:31 20m - / - ON7NQ -7 / - 9 Partial capture
08-07 16:26 20m - / - PD3PAM -19 / - 3 Partial capture
08-07 16:24 20m - / - ON7NQ -8 / - 4 Partial capture
08-07 16:21 20m - / - LA3WMA -10 / - 2 Partial capture
08-07 16:21 20m - / - ON7NQ -11 / - 2 Partial capture
08-06 16:37 20m - / -9 G3RTE -15 / - 3 ✓ Closing fragment
08-06 16:36 20m - / -16 DG1RUG -2 / - 2 ✓ Closing fragment
08-04 16:10 20m - / -13 DL0HNF +10 / - 2 ✓ Closing fragment
07-18 16:33 20m - / - PD3RH -15 / - 2 Partial capture
07-17 17:02 20m - / -8 4Z1GY -10 / - 3 ✓ Closing fragment
07-15 17:01 20m - / -21 UT5MD -8 / - 4 ✓ Closing fragment
07-15 16:43 20m - / - F6CAX -10 / - 2 Partial capture
07-15 16:41 20m - / -7 E70SZ +5 / - 3 ✓ Closing fragment
07-15 16:26 20m - / -20 UT7UJ +15 / - 2 ✓ Closing fragment
07-11 16:46 20m - / -9 ON3NR -4 / - 2 ✓ Closing fragment
07-06 16:47 20m - / - DL8HXP -3 / - 6 Partial capture
07-06 16:05 20m - / -25 IU3VHR +4 / - 4 Partial capture

Recent FT8 messages decoded at SO8OO

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

20m 
UTC    dB Audio  Message
162245  -7 1820  JA5SLV G5JCC IO93 (x3)
162345  -2 1573  JA5SLV DF7HG JO53 (x2)
162615 -15 1820  JA5SLV G5JCC IO93 (x5)
170130 +16  591  JA5SLV DK9NP -25 (x2)
145115 -15 3001  CQ JA5SLV PM74 (x2)
162700  +7  664  JA5SLV EA7R -17

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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