JH3CUL — FT8 activity observed at SO8OO

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

Receiver-side FT8 activity involving JH3CUL, decoded by SO8OO in southeastern Poland. 151 FT8 messages attributed to this token as transmitter, on 20m, across 6 UTC dates in the available aggregate history. Observed between 2026-06-16 and 2026-08-31.

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 151 FT8 messages attributed to JH3CUL as the transmitting token by decoded message structure across 6 UTC dates in the available aggregate history. The largest monitored-band total was 20 m (100%). 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 -8 dB.

Overview

151
Messages attributed
6
UTC dates decoded
21
Active 15-min windows
-8 dB
Estimated median S/N

Bands

20m · 151
First attributed message: 2026-06-16
Last attributed message: 2026-08-31 15:55 UTC

Observed FT8 message patterns

Attributed sample
151 messages
Active dates
6 UTC dates
Estimated median S/N
-8 dB
Estimated 10th-90th percentile
-17 to -1 dB
Recurring-pattern threshold
Met

SO8OO display ranges among successful decodes: weak (≤ -16 dB) 29, moderate (-15 to -9 dB) 42, strong (≥ -8 dB) 80.

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 JH3CUL 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 JH3CUL

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 · 67 decoded messages
SO8OO receiver locator
KN09VW
Locator-centre separation
8,565 km (approx.)
Last such locator decoded
2026-08-31 15:54 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 UTCBandJH3CUL S/NCounterpartCounterpart S/NMsgsCapture
09-21 15:30 160m - / -12 RA3DA +6 / - 2 ✓ Closing fragment
09-16 17:57 80m - / -17 DL8OH +12 / - 2 ✓ Closing fragment
09-08 16:18 40m - / -9 RA6ZS 0 / - 4 ✓ Closing fragment
09-08 16:17 40m - / - RN6HGI +2 / - 2 Partial capture
09-08 16:17 40m - / -11 US1CR +3 / - 3 ✓ Closing fragment
09-08 16:13 40m - / - US1CR +5 / - 3 Partial capture
09-08 16:07 40m - / -14 Z68PX -8 / - 2 Partial capture
08-31 15:53 20m -10 / -19 EA5JLB -5 / -17 4 ✓ Full exchange observed
08-31 15:52 20m -11 / - EA7KLL - / - 2 Partial capture
08-31 15:05 20m -8 / -21 M9OHM -6 / -21 3 ✓ Full exchange observed
08-31 15:00 20m -11 / -11 CT7AUT -2 / -16 5 ✓ Full exchange observed
08-31 15:00 20m - / -24 M7TUP -9 / - 2 ✓ Closing fragment
08-31 15:00 20m - / -18 GB1FBS +12 / - 3 Partial capture
08-30 16:49 80m - / -17 YO4NT +8 / - 2 ✓ Closing fragment
08-30 07:13 10m - / - IU0VOG -23 / - 3 Partial capture
08-28 23:23 20m - / -3 LY5A -5 / - 2 ✓ Closing fragment
08-28 23:17 20m - / - <...> -20 / - 2 ✓ Closing fragment
08-28 15:10 20m -2 / - DD8VJ - / - 2 Partial capture
08-28 14:56 20m -3 / - HB9ITZ - / -24 6 ✓ Closing fragment
08-28 14:53 20m - / - IW1QBR -14 / - 2 Partial capture
08-28 14:49 20m -6 / -8 ON4IQ -2 / -9 6 ✓ Full exchange observed
08-28 14:40 20m 0 / - IK2EST - / - 2 Partial capture
08-28 14:37 20m -2 / - IK1ZOV - / -14 2 ✓ Closing fragment
08-28 14:35 20m +1 / - LZ1BT - / -13 4 ✓ Closing fragment
08-28 14:34 20m +1 / - DK5FN - / -11 3 ✓ Closing fragment
08-28 14:33 20m -3 / - HA3TBL - / -14 2 ✓ Closing fragment
08-28 14:31 20m -1 / - SA7ORA - / -23 3 ✓ Closing fragment
08-28 14:27 20m -9 / - SP7FID - / -8 3 ✓ Closing fragment
08-28 14:23 20m -8 / - EC5M - / -26 6 ✓ Closing fragment
08-28 14:19 20m -8 / +1 MM3RCR +19 / -16 8 ✓ Full exchange observed
08-28 14:12 20m -4 / -7 TA2PWR -14 / -18 12 ✓ Full exchange observed
08-28 14:11 20m -1 / - SA0WAE - / -20 3 ✓ Closing fragment
08-28 14:07 20m - / - F1JPG -5 / - 4 ✓ Closing fragment
08-28 14:07 20m - / -3 IZ8EYN +8 / - 2 Partial capture
08-28 14:04 20m - / -1 F5MXH -3 / - 3 ✓ Closing fragment
08-28 14:03 20m - / +6 R6AO +8 / - 2 ✓ Closing fragment
08-28 14:01 20m -2 / - DL5MKR - / -15 3 ✓ Closing fragment
08-28 13:57 20m -16 / - K9SQ - / - 2 Partial capture
08-28 13:52 20m -14 / - KC5OCH - / -19 2 ✓ Closing fragment
08-25 22:59 20m - / -11 EA7GUK +8 / - 2 ✓ Closing fragment
08-21 14:39 20m - / -11 OE2VEL +14 / - 2 ✓ Closing fragment
08-21 14:33 20m -7 / - DL3FH -1 / - 2 ✓ Closing observed
08-21 13:43 20m - / - DL1YS 0 / - 5 Partial capture
08-21 13:41 20m -6 / - MM7UHK - / - 3 Partial capture
08-21 13:37 20m -8 / - F9SS -3 / -13 6 ✓ Closing observed
08-21 13:36 20m -7 / - EW2ZC - / -7 5 ✓ Closing fragment
08-20 23:41 20m - / -8 II7MGBT -6 / - 2 Partial capture
08-20 23:37 20m - / -11 SV5BYP -4 / - 2 ✓ Closing fragment
08-20 23:33 20m - / -16 LZ2IP -16 / - 2 ✓ Closing fragment
08-12 15:41 20m -14 / -14 4Z1GY -14 / -8 4 ✓ Closing observed

Recent FT8 messages decoded at SO8OO

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

160m 
UTC    dB Audio  Message
153015  +5 2406  JH3CUL RA3DA -12 (x2)
80m 
UTC    dB Audio  Message
164930  +6 2118  JH3CUL YO4NT -17 (x2)
175745 +16 2812  JH3CUL DL8OH -17 (x2)
40m 
UTC    dB Audio  Message
160700  -7  588  JH3CUL Z68PX -14 (x2)
161300  +7 2631  JH3CUL US1CR KN59 (x5)
161730  +1 1031  JH3CUL RN6HGI LN14
161800  +5 2630  JH3CUL US1CR 73
161800  +3 1031  JH3CUL RN6HGI LN14
161830  -2  628  JH3CUL RA6ZS KN98 (x4)
20m 
UTC    dB Audio  Message
150215  -1 1527  JH3CUL CT7AUT R-11
150230 -11  614  CT7AUT JH3CUL -16
150245  -4 1527  JH3CUL CT7AUT R-05 (x2)
150515  -8 2508  JH3CUL M9OHM -21
150530  -8  614  M9OHM JH3CUL R-21
150545  -5 2508  JH3CUL M9OHM RR73
150545  -3 1689  <JH3CUL> AO90A
154845  -9 1091  EA7KLL JH3CUL PM74 (x2)
155330  -6 1140  JH3CUL EA5JLB -19 (x2)
155445 -12 1091  EA7KLL JH3CUL PM74
155515  -9 1091  EA5JLB JH3CUL R-17 (x2)
10m 
UTC    dB Audio  Message
150930 -12 2632  JH3CUL F4LZZ JN09
114045 -11 1344  JH3CUL DN9MNE JN58
114315  +9  454  JH3CUL DO1ID JO41 (x2)
114445  -5 1093  JH3CUL DL1IP -17
114900 -11 1653  JH3CUL DN9CA -11 (x2)
120045 -10 2195  JH3CUL PD2JAM RR73
120630 -10 3085  JH3CUL DL8MBN JN58
121545 -13  769  JH3CUL OZ5VO RR73
071300 -24 1678  JH3CUL IU0VOG JN61 (x3)
083130 -14  915  JH3CUL IU5NWT -14
083715 -17 1681  JH3CUL IK3ORD RR73

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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