JA3MHV — FT8 activity observed at SO8OO

DXCC entity inferred from callsign: Japan Most frequent locator attributed to this token: PM85

Receiver-side FT8 activity involving JA3MHV, decoded by SO8OO in southeastern Poland. 159 FT8 messages attributed to this token as transmitter, on 20m, across 7 UTC dates in the available aggregate history. Observed between 2026-06-06 and 2026-08-21.

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 159 FT8 messages attributed to JA3MHV as the transmitting token by decoded message structure across 7 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 (64%), so no unique busiest interval is claimed. Most successfully decoded messages attributed to this token fell in SO8OO's strong S/N range (91%); the estimated median was -4 dB.

Overview

159
Messages attributed
7
UTC dates decoded
15
Active 15-min windows
-4 dB
Estimated median S/N

Bands

20m · 159
First attributed message: 2026-06-06
Last attributed message: 2026-08-21 15:10 UTC

Observed FT8 message patterns

Attributed sample
159 messages
Active dates
7 UTC dates
Estimated median S/N
-4 dB
Estimated 10th-90th percentile
-8 to +4 dB
Recurring-pattern threshold
Met

SO8OO display ranges among successful decodes: weak (≤ -16 dB) 0, moderate (-15 to -9 dB) 15, strong (≥ -8 dB) 144.

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 JA3MHV in decoded directed-looking exchanges:

Most frequent locator attributed to JA3MHV

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
PM85 · 85 decoded messages
SO8OO receiver locator
KN09VW
Locator-centre separation
8,586 km (approx.)
Last such locator decoded
2026-08-21 15:05 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 UTCBandJA3MHV S/NCounterpartCounterpart S/NMsgsCapture
09-20 21:45 40m - / -19 F5NBU +20 / - 3 ✓ Closing fragment
09-20 21:41 40m - / -13 OS4K -15 / - 4 Partial capture
09-18 15:59 80m - / - UX1AA -6 / - 3 Partial capture
09-18 15:55 80m - / -6 OH2XX -7 / - 2 ✓ Closing fragment
09-18 15:50 80m - / - UX1AA +1 / - 4 Partial capture
09-18 15:49 80m - / -8 OH4MDY -10 / - 2 ✓ Closing fragment
09-15 16:55 40m - / -9 RU4SS -12 / - 2 ✓ Closing fragment
09-15 16:52 40m - / - DJ0MAB -6 / - 3 Partial capture
09-15 16:49 40m - / -13 SP5MXZ -1 / - 3 ✓ Closing fragment
09-15 16:48 40m - / -18 UR5LKE -6 / - 2 ✓ Closing fragment
08-28 16:08 80m - / -21 UR4LRG +7 / - 2 ✓ Closing fragment
08-21 15:10 20m -2 / - BG5HKI - / -7 2 ✓ Closing fragment
08-21 15:09 20m -5 / - EB5CS - / -16 2 ✓ Closing fragment
08-21 15:08 20m -4 / - R2EA/P - / -11 2 ✓ Closing fragment
08-21 15:07 20m -4 / - OH1TK - / -7 2 ✓ Closing fragment
08-21 15:06 20m -4 / - ZS5HR - / -3 2 ✓ Closing fragment
08-21 14:58 20m - / - DL9IQ +2 / - 5 Partial capture
08-21 14:49 20m -2 / - 9J2MM - / - 27 Partial capture
08-14 15:52 20m -11 / - OE7KTI -18 / - 3 ✓ Closing observed
08-06 14:07 20m - / -8 F5SSQ -4 / - 4 ✓ Closing fragment
08-05 22:09 20m - / 0 7X5CY -4 / - 2 ✓ Closing fragment
08-05 15:47 20m - / +10 R4FDW -12 / - 3 ✓ Closing fragment
08-05 15:34 20m - / -3 GJ0KYZ +4 / - 2 Partial capture
07-14 15:49 20m - / - R7DX -24 / - 2 Partial capture
07-14 15:49 20m - / 0 UA9SAV -9 / - 2 ✓ Closing fragment
07-14 15:39 20m -9 / - TA3ZGR - / -15 2 Partial capture
07-14 15:36 20m - / - R6AO -20 / - 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
165230  -8 1642  JA3MHV DJ0MAB JN49 (x3)
165500 -12 2219  JA3MHV RU4SS R-09 (x2)
165730  -5  642  JA3MHV RN6M KN97
214015 -18 1728  JA3MHV HZ1TT -11
214115 -12 1881  JA3MHV OS4K -13 (x4)
214400  -3  606  JA3MHV II9IAGM -08
214500 +17 2704  JA3MHV F5NBU JN28 (x3)
80m 
UTC    dB Audio  Message
160800  +8  396  JA3MHV UR4LRG -21 (x2)
154930  -9  985  JA3MHV OH4MDY -08
155000  +2 2225  JA3MHV UX1AA KO70
155000 -12  985  JA3MHV OH4MDY RR73
155030  +3 2225  JA3MHV UX1AA KO70 (x3)
155530  -6  586  JA3MHV OH2XX -06 (x2)
155900  -7 2225  JA3MHV UX1AA KO70 (x3)
20m 
UTC    dB Audio  Message
150315  -4  833  9J2MM JA3MHV PM85 (x3)
150615  -3  833  ZS5HR JA3MHV -03 (x2)
150715  -5  833  OH1TK JA3MHV -07 (x2)
150815  -4  833  R2EA/P JA3MHV R-11 (x2)
150915  -6  833  EB5CS JA3MHV -16 (x2)
151000 -11  834  JA3MHV OE9NET JN47
151015  -1  833  BG5HKI JA3MHV R-07 (x2)
233100 -13  716  JA3MHV RR73; JA2GHP <TT1GD> -18
10m 
UTC    dB Audio  Message
145945 +11  814  JA3MHV SV7BAY -12

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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