UD4F — FT8 activity observed at SO8OO

DXCC entity inferred from callsign: European Russia Most frequent locator attributed to this token: LO23

Receiver-side FT8 activity involving UD4F, decoded by SO8OO in southeastern Poland. 163 FT8 messages attributed to this token as transmitter, on 160m, 80m, 40m, 20m, 10m, across 13 UTC dates in the available aggregate history. Observed between 2026-06-19 and 2026-09-21.

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 163 FT8 messages attributed to UD4F as the transmitting token by decoded message structure across 13 UTC dates in the available aggregate history. The largest monitored-band total was 10 m (64%), followed by 160 m (16%) and 80 m (12%). Several six-hour UTC windows tied for the largest share (64%), 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

163
Messages attributed
13
UTC dates decoded
29
Active 15-min windows
-11 dB
Estimated median S/N

Bands

160m · 26 80m · 20 40m · 7 20m · 6 10m · 104
First attributed message: 2026-06-19
Last attributed message: 2026-09-21 14:56 UTC

Observed FT8 message patterns

Attributed sample
163 messages
Active dates
13 UTC dates
Estimated median S/N
-11 dB
Estimated 10th-90th percentile
-20 to +6 dB
Recurring-pattern threshold
Met

SO8OO display ranges among successful decodes: weak (≤ -16 dB) 51, moderate (-15 to -9 dB) 45, strong (≥ -8 dB) 67.

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 UD4F 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 UD4F

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 · 26 decoded messages
SO8OO receiver locator
KN09VW
Locator-centre separation
1,639 km (approx.)
Last such locator decoded
2026-09-21 14:55 UTC

Other locator fields attributed to this token: LO22 (6) and LO33 (1).

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 UTCBandUD4F S/NCounterpartCounterpart S/NMsgsCapture
09-21 14:55 160m -14 / - KH8WW - / -19 3 ✓ Closing fragment
09-21 02:15 160m - / - PA3KUS -7 / - 2 Partial capture
09-21 02:09 160m +8 / - V26OC - / -22 10 ✓ Closing fragment
09-21 01:32 160m - / +1 RK8W -11 / - 2 Partial capture
09-21 01:31 160m +11 / - V26OC - / - 2 Partial capture
09-19 18:24 160m -9 / - RI1FJZ - / -12 3 ✓ Closing fragment
09-16 15:08 80m -13 / - KH8WW - / -19 3 ✓ Closing fragment
08-29 22:28 160m +2 / - RI1FJL - / -19 8 Partial capture
08-26 19:15 80m -2 / - RI1FJL - / -7 15 Partial capture
07-25 03:44 20m - / +5 YO4NF -8 / - 2 Partial capture
07-13 15:06 40m -8 / - RI1PC - / -5 3 Partial capture
07-13 15:01 40m -13 / - RI1PC - / -5 2 Partial capture
07-10 10:27 10m - / +7 PA0HCL -24 / - 2 ✓ Closing fragment
07-10 09:01 10m -10 / - DO1ID - / +7 2 Partial capture
07-10 09:00 10m -12 / - OZ7FOC - / -4 2 ✓ Closing fragment
07-10 08:51 10m -19 / - OE3ZIO - / -5 3 Partial capture
07-10 08:46 10m -18 / - DL1UDO - / -9 2 Partial capture
07-10 08:40 10m -17 / - G3VCQ - / +3 2 ✓ Closing fragment
07-09 09:51 10m -4 / - EA3EDU - / - 3 Partial capture
07-09 09:48 10m -5 / - DG6TOM - / -1 3 ✓ Closing fragment
07-09 09:47 10m -6 / - YU6DX - / +9 2 ✓ Closing fragment
07-09 09:46 10m -2 / - EA4FVT - / - 2 Partial capture
07-09 09:44 10m -6 / - EA5LZ - / +1 2 Partial capture
07-09 09:42 10m -6 / - EC1DIR - / +3 3 ✓ Closing fragment
07-09 09:41 10m -4 / - EA5LZ - / +4 2 Partial capture
07-09 09:38 10m -12 / - F5CUN - / +9 2 ✓ Closing fragment
07-09 09:36 10m -18 / - EA1IIF - / - 4 Partial capture
07-09 09:32 10m -16 / - CT7AUT - / -6 2 ✓ Closing fragment
07-09 09:28 10m -18 / - EA3RCK - / - 2 Partial capture
07-09 09:26 10m -22 / -1 IU3UNC -24 / -4 4 ✓ Full exchange observed
07-09 08:26 10m -16 / - OH5FI - / +1 2 ✓ Closing fragment
07-09 08:23 10m -10 / - DO7TTR - / -12 3 Partial capture
07-09 08:21 10m -8 / - YU1BV - / -1 2 ✓ Closing fragment
07-09 08:13 10m -20 / - S59A - / - 2 ✓ Closing fragment
07-09 06:01 10m - / - R6TA -8 / - 4 Partial capture
07-08 12:49 10m -20 / -20 DO6FM -12 / - 4 ✓ Closing observed
07-08 12:46 10m -18 / - EA3ISZ - / -12 2 Partial capture
07-08 12:43 10m -16 / - EA3ISZ - / -8 2 Partial capture
07-08 12:21 10m - / -20 DL8LE -14 / - 5 Partial capture
07-08 12:13 10m -11 / - OH3DJP - / 0 2 ✓ Closing fragment
07-08 12:02 10m -21 / - EB5HRZ - / +6 2 ✓ Closing fragment
07-08 11:58 10m -8 / - DO7BE - / -2 2 ✓ Closing fragment
07-08 11:53 10m - / -12 IK1UGX -12 / - 2 ✓ Closing fragment
07-08 11:46 10m -11 / - LA1HW - / -9 2 Partial capture
07-08 11:39 10m -15 / - DL2HRT - / -8 2 Partial capture
07-08 11:38 10m -18 / - EA5QS - / -3 2 ✓ Closing fragment
07-08 11:19 10m -18 / - EA5QS - / -7 2 Partial capture
07-08 11:13 10m -12 / -4 HB9DBM -6 / 0 3 ✓ Full exchange observed
07-08 11:07 10m - / - RL3K -15 / - 3 Partial capture
07-07 12:54 10m - / - DN9AD -17 / - 2 Partial capture

Recent FT8 messages decoded at SO8OO

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

160m 
UTC    dB Audio  Message
020945 +13  891  V26OC UD4F LO23 (x9)
021430  +3 1509  UD4F RM5F KO85
021530  -7  905  UD4F PA3KUS JO21 (x2)
145515 -10 1166  KH8WW UD4F LO23 (x3)
80m 
UTC    dB Audio  Message
191745  -9  368  RI1FJL UD4F LO23 (x3)
192100  +5 1016  UD4F 5B4VL -02
192145  -3  368  RI1FJL UD4F LO22 (x8)
150845 -15 1602  KH8WW UD4F -19 (x3)
20m 
UTC    dB Audio  Message
034245  +0 3035  CQ UD4F LO33
034315  +0 3035  VE4ZIM UD4F R-13
034400  -7 3035  UD4F YO4NF +05 (x2)
40m 
UTC    dB Audio  Message
145415 -14 2542  RI1PC UD4F -14 (x7)
10m 
UTC    dB Audio  Message
084115 -15 1796  G3VCQ UD4F RR73
084600 -17 1564  DL1UDO UD4F -09 (x2)
084930  -4  583  <...> UD4F -01
085145 -18 1570  OE3ZIO UD4F -05 (x3)
085345  -6  605  SP9JMZ UD4F +04
085945 -17 1381  OK2VX UD4F +12
090045 -12 1281  OZ7FOC UD4F -04
090145 -11  837  DO1ID UD4F +07 (x2)
090245 -11  837  OZ7FOC UD4F RR73
102745 -24 1563  UD4F PA0HCL R+07 (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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