JA4FDZ — FT8 activity observed at SO8OO
Receiver-side FT8 activity involving JA4FDZ, decoded by SO8OO in southeastern Poland. 85 FT8 messages attributed to this token as transmitter, on 40m, 20m, across 10 UTC dates in the available aggregate history. Observed between 2026-06-10 and 2026-08-27.
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 85 FT8 messages attributed to JA4FDZ as the transmitting token by decoded message structure across 10 UTC dates in the available aggregate history. The largest monitored-band total was 20 m (73%), followed by 40 m (27%). Several six-hour UTC windows tied for the largest share (100%), so no unique busiest interval is claimed. Received S/N was mixed across SO8OO's weak, moderate and strong ranges; the estimated median was -11 dB.
Overview
Bands
Last attributed message: 2026-08-27 20:55 UTC
Observed FT8 message patterns
- Attributed sample
- 85 messages
- Active dates
- 10 UTC dates
- Estimated median S/N
- -11 dB
- Estimated 10th-90th percentile
- -20 to -5 dB
- Recurring-pattern threshold
- Met
SO8OO display ranges among successful decodes: weak (≤ -16 dB) 18, moderate (-15 to -9 dB) 49, strong (≥ -8 dB) 18.
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 JA4FDZ 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 JA4FDZ
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
- PM64 · 35 decoded messages
- SO8OO receiver locator
- KN09VW
- Locator-centre separation
- 8,453 km (approx.)
- Last such locator decoded
- 2026-08-27 20:51 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 | JA4FDZ S/N | Counterpart | Counterpart S/N | Msgs | Capture |
|---|---|---|---|---|---|---|
| 09-18 20:36 | 40m | - / - | R3KGN | -3 / - | 3 | Partial capture |
| 09-18 20:19 | 40m | - / - | PA3KUS | -24 / - | 2 | Partial capture |
| 09-18 20:13 | 40m | - / -20 | F5NBU | +14 / - | 5 | ✓ Closing fragment |
| 09-18 20:01 | 40m | - / - | EB1LA | -14 / - | 4 | Partial capture |
| 09-18 19:52 | 40m | - / -14 | R6YG | -10 / - | 4 | ✓ Closing fragment |
| 09-18 19:52 | 40m | - / 0 | R7CD | -7 / - | 3 | ✓ Closing fragment |
| 09-18 19:49 | 40m | - / -18 | UR5UK | -9 / - | 2 | Partial capture |
| 09-18 19:44 | 40m | - / - | EB1LA | -4 / - | 6 | Partial capture |
| 09-18 19:44 | 40m | - / -14 | R2ASD | -8 / - | 2 | Partial capture |
| 09-18 19:44 | 40m | - / - | R7CD | +1 / - | 3 | Partial capture |
| 09-17 20:52 | 40m | - / - | RY3QAB | +6 / - | 2 | Partial capture |
| 09-17 20:51 | 40m | - / -9 | OH8KA | -4 / - | 3 | ✓ Closing fragment |
| 08-31 20:10 | 40m | - / -7 | RZ6AKF | +4 / - | 4 | ✓ Closing fragment |
| 08-31 20:09 | 40m | - / -14 | DL3KBB | +4 / - | 4 | ✓ Closing fragment |
| 08-31 20:09 | 40m | - / - | PA1GLD | +5 / - | 5 | Partial capture |
| 08-31 20:07 | 40m | - / -24 | IT9VCE | -3 / - | 3 | ✓ Closing fragment |
| 08-31 20:02 | 40m | - / -15 | OE1AVO | +1 / - | 3 | ✓ Closing fragment |
| 08-30 20:55 | 40m | - / - | PA7AK | -3 / - | 8 | Partial capture |
| 08-30 20:53 | 40m | - / - | SP3TD | -8 / - | 2 | Partial capture |
| 08-30 20:52 | 40m | - / - | R3SN | -10 / - | 2 | Partial capture |
| 08-30 20:50 | 40m | - / -12 | IU1TLK | +1 / - | 3 | ✓ Closing fragment |
| 08-30 20:43 | 40m | - / - | S56UVB | +3 / - | 4 | Partial capture |
| 08-27 20:50 | 40m | -10 / -19 | M0XUE | -5 / -19 | 10 | ✓ Full exchange observed |
| 08-27 20:48 | 40m | -8 / -12 | YT1DDL | -6 / -22 | 4 | ✓ Full exchange observed |
| 08-27 20:44 | 40m | - / - | EA5FGC | -6 / - | 2 | Partial capture |
| 08-27 20:44 | 40m | -10 / -22 | YO3APJ | 0 / -15 | 8 | ✓ Full exchange observed |
| 08-27 20:42 | 40m | - / -16 | R7ZY | 0 / - | 3 | ✓ Closing fragment |
| 08-27 20:40 | 40m | - / -15 | SV1DKR | -3 / - | 4 | ✓ Closing fragment |
| 08-27 20:38 | 40m | -10 / -9 | ON6DL | -10 / -13 | 4 | Partial capture |
| 08-27 20:36 | 40m | -13 / - | PD2XX | - / - | 2 | Partial capture |
| 08-27 20:36 | 40m | - / - | R7ZY | 0 / - | 2 | Partial capture |
| 08-27 20:34 | 40m | - / -13 | G6PWS | -12 / - | 3 | ✓ Closing fragment |
| 08-22 20:53 | 40m | - / +3 | F1PBZ | -1 / - | 3 | Partial capture |
| 08-22 20:53 | 40m | - / - | HA5IKS | -9 / - | 2 | Partial capture |
| 08-22 20:46 | 40m | - / -15 | TA3NK | -7 / - | 6 | ✓ Closing fragment |
| 08-22 20:39 | 40m | - / - | F1IQH | -10 / - | 2 | Partial capture |
| 08-21 20:44 | 40m | - / -16 | DL7HS | +8 / - | 3 | ✓ Closing fragment |
| 08-21 20:41 | 40m | - / -17 | EA5OL | -1 / - | 4 | ✓ Closing fragment |
| 08-20 20:47 | 40m | - / -12 | ON4IQ | +18 / - | 3 | ✓ Closing fragment |
| 08-20 20:41 | 40m | - / - | ON/PA1POS | -4 / - | 4 | Partial capture |
| 08-20 20:41 | 40m | - / - | 9A7BB | -4 / - | 4 | Partial capture |
| 08-20 20:29 | 40m | - / - | F4ENK | +3 / - | 2 | Partial capture |
| 08-20 20:29 | 40m | - / - | DF8AA | -9 / - | 3 | Partial capture |
| 08-20 20:29 | 40m | - / -20 | SM0IJS | -10 / - | 2 | Partial capture |
| 08-20 20:23 | 40m | - / -12 | DJ1OJ | +10 / - | 5 | ✓ Closing fragment |
| 08-20 20:22 | 40m | - / -20 | SP2WEI | +4 / - | 2 | Partial capture |
| 08-20 20:20 | 40m | - / - | 4X5JK | -9 / - | 2 | ✓ Closing fragment |
| 08-20 20:15 | 40m | - / -13 | US7UR | +6 / - | 4 | ✓ Closing fragment |
| 08-20 20:10 | 40m | - / -21 | SP9CVY | -4 / - | 2 | ✓ Closing fragment |
| 08-20 20:07 | 40m | - / -16 | F5NIB | -2 / - | 15 | ✓ Closing fragment |
Recent FT8 messages decoded at SO8OO
Frequency values are decoder audio offsets in hertz, not RF frequencies.
UTC dB Audio Message 200200 -15 1469 JA4FDZ EB1LA IN73 (x2) 201300 +14 772 JA4FDZ F5NBU JN28 (x5) 201800 -9 1366 JA4FDZ PD7BB JO32 201900 -24 2234 JA4FDZ PA3KUS JO21 (x3) 203330 -8 1569 JA4FDZ IK6GPZ R-22 203630 -6 1525 JA4FDZ R3KGN KO90 (x3)
UTC dB Audio Message 204915 -14 1907 JA4FDZ SV5BYP 73 203215 -15 977 JA4FDZ ON4AZR JO21 205130 +0 682 JA4FDZ PA4O JO33 (x5) 205400 -10 752 JA4FDZ PD2JAM JO22 205400 -3 681 JA4FDZ PA4O R-12 200815 -11 1221 JA4FDZ DL3JJ R-15 (x3) 213630 -18 1993 5N0YEN JA4FDZ PM64 (x2) 214945 -14 2464 RI1FJL JA4FDZ PM64
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.
FT8DB and SO8OO WebSDR are a hobby project maintained solo. ☕ Buy me a coffee