RK4FAJ — FT8 activity observed at SO8OO
Receiver-side FT8 activity involving RK4FAJ, decoded by SO8OO in southeastern Poland. 1,459 FT8 messages attributed to this token as transmitter, on 160m, 80m, 40m, 20m, across 53 UTC dates in the available aggregate history. Observed between 2026-06-13 and 2026-10-13.
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 1,459 FT8 messages attributed to RK4FAJ as the transmitting token by decoded message structure across 53 UTC dates in the available aggregate history. The largest monitored-band total was 40 m (49%), followed by 80 m (32%) and 20 m (14%). The busiest six-hour window was 15:00-21:00 UTC, containing 46% of decodes. Received S/N was mixed across SO8OO's weak, moderate and strong ranges; the estimated median was -11.8 dB.
Overview
Bands
Last attributed message: 2026-10-13 05:01 UTC
Observed FT8 message patterns
- Attributed sample
- 1,459 messages
- Active dates
- 53 UTC dates
- Estimated median S/N
- -11.8 dB
- Estimated 10th-90th percentile
- -19 to -1 dB
- Recurring-pattern threshold
- Met
SO8OO display ranges among successful decodes: weak (≤ -16 dB) 400, moderate (-15 to -9 dB) 536, strong (≥ -8 dB) 523.
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 RK4FAJ 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 RK4FAJ
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
- LO23 · 934 decoded messages
- SO8OO receiver locator
- KN09VW
- Locator-centre separation
- 1,639 km (approx.)
- Last such locator decoded
- 2026-10-13 05:01 UTC
Other locator fields attributed to this token: LO22 (6).
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 | RK4FAJ S/N | Counterpart | Counterpart S/N | Msgs | Capture |
|---|---|---|---|---|---|---|
| 10-13 04:59 | 40m | -22 / - | IU5VMC | - / -22 | 3 | ✓ Closing fragment |
| 10-13 04:53 | 40m | -14 / +8 | R3TKM | -13 / +3 | 5 | ✓ Full exchange observed |
| 10-13 04:51 | 40m | -15 / - | F4ELU | - / -9 | 3 | ✓ Closing fragment |
| 10-13 04:49 | 40m | -17 / -14 | R3DIH | -14 / -1 | 5 | ✓ Full exchange observed |
| 10-13 04:46 | 40m | -14 / - | US1EA | -24 / -3 | 5 | ✓ Full exchange observed |
| 10-13 04:45 | 40m | -18 / - | IU3ACL | - / - | 2 | ✓ Closing fragment |
| 10-13 04:41 | 40m | -15 / - | SV5AZK | -24 / -18 | 2 | Partial capture |
| 10-13 04:36 | 40m | -14 / - | IK2SYK | -15 / -9 | 4 | ✓ Closing observed |
| 10-13 04:34 | 40m | -10 / - | UB6LLI | - / -14 | 2 | ✓ Closing fragment |
| 10-13 04:33 | 40m | -12 / - | RA8CO | - / -12 | 2 | ✓ Closing fragment |
| 10-13 04:31 | 40m | -8 / - | UA9SY | - / -9 | 2 | ✓ Closing fragment |
| 10-13 04:29 | 40m | -12 / -17 | SV1ENG | -10 / -12 | 6 | ✓ Full exchange observed |
| 10-13 04:28 | 40m | -18 / - | UA3WG | -19 / -1 | 3 | ✓ Closing observed |
| 10-12 01:57 | 40m | - / -9 | 9H6C | -20 / - | 3 | Partial capture |
| 10-09 03:58 | 40m | - / - | SV1ENG | -2 / - | 5 | Partial capture |
| 10-09 03:55 | 40m | -18 / - | YU65AEC | - / -8 | 2 | Partial capture |
| 10-09 03:50 | 40m | -12 / -11 | R7OI | -11 / -13 | 17 | ✓ Full exchange observed |
| 10-08 15:16 | 40m | -12 / - | RA6FCU/P | - / - | 2 | Partial capture |
| 10-08 15:05 | 40m | -14 / +1 | RA6FCU/P | -1 / +3 | 8 | ✓ Full exchange observed |
| 10-08 14:18 | 40m | -18 / - | YC2BUZ | - / - | 3 | Partial capture |
| 10-08 14:05 | 40m | - / -4 | R80SAA | +1 / - | 2 | ✓ Closing fragment |
| 10-08 13:55 | 40m | - / -3 | R3DID | -14 / - | 2 | ✓ Closing fragment |
| 10-07 18:36 | 80m | -17 / -21 | R1BLO/P | -10 / -20 | 4 | Partial capture |
| 10-07 18:31 | 40m | -6 / - | R6AEB | - / - | 3 | Partial capture |
| 10-07 17:11 | 80m | -6 / - | UA1CKA | - / - | 2 | Partial capture |
| 10-07 02:28 | 80m | - / - | DL5DQZ | -5 / - | 3 | Partial capture |
| 10-07 02:25 | 80m | -13 / -14 | UA9FMT | -14 / -12 | 4 | ✓ Full exchange observed |
| 10-06 14:09 | 40m | - / - | PA0WDN | -21 / - | 3 | Partial capture |
| 10-06 13:59 | 40m | -10 / - | UA4QK | - / - | 3 | Partial capture |
| 10-06 13:33 | 40m | -18 / - | 6L0LV | - / - | 2 | Partial capture |
| 10-06 13:18 | 40m | -12 / - | YD1EQN | - / - | 2 | Partial capture |
| 10-06 13:14 | 40m | - / -6 | UA3MLR | -17 / - | 3 | ✓ Closing fragment |
| 10-06 04:15 | 40m | -16 / -2 | R6OV | -14 / -6 | 10 | ✓ Full exchange observed |
| 10-06 04:11 | 40m | -20 / - | M0PJE/P | - / -17 | 5 | Partial capture |
| 10-06 04:09 | 40m | -8 / - | RN8C/M | - / - | 3 | Partial capture |
| 10-06 03:56 | 40m | -14 / - | R8KAW/P | - / -23 | 6 | ✓ Closing fragment |
| 10-06 03:44 | 40m | -8 / - | IT9ACJ/ISUB | - / -15 | 2 | Partial capture |
| 10-06 02:35 | 40m | - / - | CT3MD | -9 / - | 4 | Partial capture |
| 10-05 18:48 | 80m | -17 / -5 | RX3VF | 0 / -9 | 5 | ✓ Full exchange observed |
| 10-05 18:46 | 80m | -12 / - | R4RJ | - / -4 | 4 | ✓ Closing fragment |
| 10-05 00:54 | 80m | - / - | EB1LA | +12 / - | 2 | Partial capture |
| 10-05 00:53 | 80m | - / - | ON4MAP | -13 / - | 6 | Partial capture |
| 10-05 00:43 | 80m | -10 / -1 | RW9MZ | -5 / -3 | 6 | ✓ Full exchange observed |
| 10-05 00:39 | 80m | -9 / +2 | SX2LGT | -2 / -9 | 5 | ✓ Full exchange observed |
| 10-05 00:38 | 80m | -10 / -17 | DO4TYW | +1 / -22 | 17 | ✓ Full exchange observed |
| 10-05 00:36 | 80m | - / -15 | GM6URC | -2 / - | 2 | ✓ Closing fragment |
| 10-04 04:20 | 40m | -16 / - | RA6LTD | - / -7 | 3 | ✓ Closing fragment |
| 09-19 19:24 | 160m | -11 / - | RI1FJZ | - / -19 | 2 | Partial capture |
| 09-17 02:55 | 40m | -4 / - | W1RQ | - / - | 4 | Partial capture |
| 09-17 02:52 | 40m | -2 / - | R1OAX | - / -2 | 3 | ✓ Closing fragment |
Recent FT8 messages decoded at SO8OO
Frequency values are decoder audio offsets in hertz, not RF frequencies.
UTC dB Audio Message 022730 -10 1891 CQ RK4FAJ LO23 (x2) 022815 -1 1892 RK4FAJ DL5DQZ JO61 022830 -16 1891 CQ RK4FAJ LO23 022845 -3 1892 RK4FAJ DL5DQZ JO61 022900 -14 1891 CQ RK4FAJ LO23 022915 -10 1891 RK4FAJ DL5DQZ JO61 022945 -3 1182 RK4FAJ F5RAV JN09 171130 -8 2311 UA1CKA RK4FAJ LO23 (x2) 183645 -17 1787 R1BLO/P RK4FAJ LO23 (x2) 183730 -10 1787 RK4FAJ R1BLO/P -21 183745 -16 1787 R1BLO/P RK4FAJ R-20 154100 -10 2482 RK4FAJ RR73; UA3NFG <...> -08
UTC dB Audio Message 045430 -11 1948 CQ RK4FAJ LO23 (x10) 045930 -21 1946 IU5VMC RK4FAJ LO23 (x3) 050100 -20 1945 CQ RK4FAJ LO23 (x2)
UTC dB Audio Message 201015 +7 1821 RK4FAJ OK1TP -16 (x2) 201145 -15 1391 RK4FAJ R2SN RR73 201200 -22 1821 R2SN RK4FAJ 73 201230 -21 1822 RU3DBT RK4FAJ -12 201345 +6 1389 RK4FAJ RZ6BS KN96 (x2) 201430 -24 1822 RZ6BS RK4FAJ RR73 201530 -22 1822 RU3DBT RK4FAJ RR73 201830 -7 2499 RK4FAJ R6JAG -03 (x2) 201930 +7 899 RK4FAJ YO9HP -17 202215 -16 898 YO9HP RK4FAJ R-21 192415 -11 927 RI1FJZ RK4FAJ LO23 (x2)
UTC dB Audio Message 134215 +10 2915 RI0FA RK4FAJ -15 (x3) 144500 -7 2259 R6YBU RK4FAJ LO23 235300 -24 1464 YV6BXN RK4FAJ LO23 054245 -4 2537 R8QA/M RK4FAJ LO23 (x10)
UTC dB Audio Message 101730 -20 1796 RK4FAJ RA6AR R-22 145215 -21 1600 RK4FAJ RW6HP LN14 (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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