JH5HDA — FT8 activity observed at SO8OO

DXCC entity inferred from callsign: Japan Most frequent locator attributed to this token: PM63

Receiver-side FT8 activity involving JH5HDA, decoded by SO8OO in southeastern Poland. 119 FT8 messages attributed to this token as transmitter, on 20m, across 11 UTC dates in the available aggregate history. Observed between 2026-06-06 and 2026-06-19.

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 119 FT8 messages attributed to JH5HDA as the transmitting token by decoded message structure across 11 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 (99%), so no unique busiest interval is claimed. Received S/N was mixed across SO8OO's weak, moderate and strong ranges; the estimated median was -16 dB.

Overview

119
Messages attributed
11
UTC dates decoded
29
Active 15-min windows
-16 dB
Estimated median S/N

Bands

First attributed message: 2026-06-06
Last attributed message: 2026-06-19 22:22 UTC

Observed FT8 message patterns

Attributed sample
119 messages
Active dates
11 UTC dates
Estimated median S/N
-16 dB
Estimated 10th-90th percentile
-22 to -11 dB
Recurring-pattern threshold
Met

SO8OO display ranges among successful decodes: weak (≤ -16 dB) 68, moderate (-15 to -9 dB) 48, strong (≥ -8 dB) 3.

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.

Most frequent locator attributed to JH5HDA

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
PM63 · 93 decoded messages
SO8OO receiver locator
KN09VW
Locator-centre separation
8,540 km (approx.)
Last such locator decoded
2026-06-19 22:22 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 UTCBandJH5HDA S/NCounterpartCounterpart S/NMsgsCapture
09-20 20:39 40m - / -15 RW3ZC +14 / - 2 Partial capture
09-19 21:32 40m - / -19 F4CVQ +10 / - 2 ✓ Closing fragment
09-19 21:13 40m - / -20 CN8NS -5 / - 2 Partial capture
09-18 20:55 40m - / -18 R3ST +4 / - 2 ✓ Closing fragment
09-15 20:20 40m - / -6 PI4DX +6 / - 2 ✓ Closing fragment
09-13 20:34 40m - / -19 R1BNJ -1 / - 2 Partial capture
09-13 20:17 40m - / -14 RK2A +2 / - 2 ✓ Closing fragment
09-12 20:19 40m - / -9 9A5E +9 / - 3 ✓ Closing fragment
09-10 21:02 40m - / -5 I0KJX -1 / - 2 ✓ Closing fragment
09-10 20:59 40m - / -14 GW0ARK -3 / - 4 ✓ Closing fragment
09-07 20:38 40m - / -11 4X1UF -9 / - 3 ✓ Closing fragment
09-07 20:29 40m - / -19 RY4ABB -5 / - 2 ✓ Closing fragment
09-06 21:21 40m - / -23 R8CKD -10 / - 2 ✓ Closing fragment
09-06 21:15 40m - / -24 DL6NDN 0 / - 2 ✓ Closing fragment
09-05 20:34 40m - / -15 OZ7KJ/P +10 / - 2 ✓ Closing fragment
08-28 23:22 20m - / +1 IK4HLQ -6 / - 2 ✓ Closing fragment
08-28 21:56 20m - / -19 IK4HLQ +6 / - 5 Partial capture
08-27 20:28 40m - / -17 SP9NR +17 / - 3 ✓ Closing fragment
08-26 22:19 20m - / -24 M0OVG -7 / - 3 Partial capture
08-26 22:11 20m - / -19 EA5OM +7 / - 4 ✓ Closing fragment
08-26 22:02 20m - / -16 9A3TY -11 / - 2 ✓ Closing fragment
08-26 22:01 20m - / -22 EA8AJ -2 / - 2 ✓ Closing fragment
08-26 21:04 40m - / -21 RK1B -6 / - 3 ✓ Closing fragment
08-26 20:53 40m - / - DL1GLO +5 / - 5 Partial capture
08-26 20:53 40m - / -15 RL3T +2 / - 3 ✓ Closing fragment
08-25 13:02 20m - / - ON7NQ -4 / - 5 Partial capture
08-22 21:42 20m - / -2 DA1EA +10 / - 2 ✓ Closing fragment
08-22 20:33 40m - / - M0LAD +7 / - 16 Partial capture
08-22 20:30 40m - / - DM5KK +7 / - 4 Partial capture
08-22 20:29 60m - / - DL8LE +1 / - 11 Partial capture
08-22 20:21 40m - / -16 R3PY -6 / - 2 ✓ Closing fragment
08-22 13:54 20m - / -11 ON4IQ +14 / - 2 ✓ Closing fragment
08-20 23:20 20m - / -18 TJ1GD -10 / - 2 Partial capture
08-20 23:01 20m - / -20 YO5OHY -12 / - 2 Partial capture
08-20 20:49 40m - / -18 HA3GO +8 / - 7 Partial capture
08-20 20:15 40m - / -13 SP8NR -8 / - 2 ✓ Closing fragment
08-20 13:11 20m - / -15 R4UA 0 / - 2 ✓ Closing fragment
08-19 20:28 40m - / -13 OE3GCU +1 / - 3 ✓ Closing fragment
08-17 21:18 40m - / -14 SP8NR -8 / - 3 Partial capture
08-17 20:32 40m - / -20 SN1A -11 / - 3 ✓ Closing fragment
08-17 20:17 40m - / -18 ON4AOI -2 / - 3 ✓ Closing fragment
08-17 20:16 40m - / - RQ6Z -4 / - 2 Partial capture
08-16 22:45 20m - / -25 PA3DP -8 / - 2 Partial capture
08-16 20:28 40m - / -13 ON4ASV 0 / - 2 ✓ Closing fragment
08-14 23:01 20m - / -19 S57LU -4 / - 3 Partial capture
08-14 20:17 40m - / -2 YO9BGU -10 / - 4 Partial capture
08-11 20:47 40m - / -9 OM3TWM -3 / - 2 Partial capture
08-10 21:53 20m - / -15 9A4N -4 / - 2 ✓ Closing fragment
08-10 21:03 20m - / -10 DK7NL +4 / - 2 Partial capture
08-07 22:29 20m - / -12 IU8FRE -19 / - 2 Partial capture

Recent FT8 messages decoded at SO8OO

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

40m
UTC    dB Audio  Message
202545  -4 2682  JH5HDA R1BNJ -19 (x3)
203330  +1 2491  JH5HDA R7ZY RR73
203730 -10  227  JH5HDA RU3KA RR73
202000  +8 2359  JH5HDA PI4DX -06 (x2)
205545  +6  988  JH5HDA R3ST -18 (x2)
211330  -7 1886  JH5HDA CN8NS -20 (x2)
213230  +6  372  JH5HDA F4CVQ -19 (x2)
203900 +13 2926  JH5HDA RW3ZC -15 (x2)
20m
UTC    dB Audio  Message
221145  +6 2482  JH5HDA EA5OM -19 (x3)
221915  -5  631  JH5HDA M0OVG -24 (x3)
132800 -17 1717  JH5HDA UA9QFF -04
215630  +6 1968  JH5HDA IK4HLQ -19 (x7)
224130 -19 1942  JH5HDA 9A3MRN RR73
60m
UTC    dB Audio  Message
202930  -1 1608  JH5HDA DL8LE JN68 (x11)
10m
UTC    dB Audio  Message
083815  -9 1593  JH5HDA LZ2CP R-06 (x2)
081245  -9 1430  JH5HDA R3OR -17 (x2)

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