JA4HDO — reception at SO8OO

Signals decoded by SO8OO in southeastern Poland. FT8 and CW have separate histories; all times are UTC.

FT8 activity

DXCC entity inferred from callsign: Japan Most frequent locator attributed to this token: PM64

Receiver-side FT8 activity involving JA4HDO, decoded by SO8OO in southeastern Poland. 21 FT8 messages attributed to this token as transmitter, on 40m, 20m, across 2 UTC dates in the available aggregate history. Observed between 2026-06-06 and 2026-09-22.

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 21 FT8 messages attributed to JA4HDO as the transmitting token by decoded message structure across 2 UTC dates in the available aggregate history. The largest monitored-band total was 20 m (86%), followed by 40 m (14%). In this small sample, the estimated median decoder S/N was 0 dB; no usual signal pattern is inferred.

Overview

Messages attributed

UTC dates decoded

Active 15-min windows

0 dB

Estimated median S/N

Bands

40m · 3 20m · 18

First attributed message: 2026-06-06
Last attributed message: 2026-09-22 21:06 UTC

Observed FT8 message patterns

Attributed sample: 21 messages
Active dates: 2 UTC dates
Estimated median S/N: 0 dB
Estimated 10th-90th percentile: -16 to +3 dB
Recurring-pattern threshold: Not met

SO8OO display ranges among successful decodes: weak (≤ -16 dB) 3, moderate (-15 to -9 dB) 0, strong (≥ -8 dB) 18.

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. The sample does not meet the threshold for a recurring time or signal-pattern claim (20 attributed messages, three UTC dates and five distinct 15-minute windows).

Frequent counterpart tokens observed at SO8OO

Tokens most often paired with JA4HDO in decoded directed-looking exchanges:

4J3DJ · Azerbaijan UB3IBG · European Russia 5B4AMM · Cyprus 9A5CW · Croatia HB9ELE · Switzerland PI4DX · Netherlands SM7TZK · Sweden TF4M · Iceland

Most frequent locator attributed to JA4HDO

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: PM64 · 15 decoded messages
SO8OO receiver locator: KN09VW
Locator-centre separation: 8,453 km (approx.)
Last such locator decoded: 2026-09-22 21:05 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 UTC	Band	JA4HDO S/N	Counterpart	Counterpart S/N	Msgs	Capture
10-17 21:05	160m	- / -18	4J3DJ	-8 / -	2	✓ Closing fragment
10-03 21:44	40m	- / -12	UF5F	-7 / -	6	Partial capture
10-03 21:43	40m	- / -24	HB9ELE	-5 / -	5	✓ Closing fragment
10-03 20:53	160m	- / -11	UB3IBG	-6 / -	2	✓ Closing fragment
09-22 21:41	40m	- / -	MI7XHT	-10 / -	2	Partial capture
09-22 21:23	40m	- / -24	G5IAN	-1 / -	2	Partial capture
09-22 21:22	40m	- / -	HB9ELE	+6 / -	5	Partial capture
09-22 21:22	40m	- / -	M8ALE	-4 / -	4	Partial capture
09-22 21:04	40m	-18 / -17	SM7TZK	+6 / -	8	✓ Closing observed
09-22 20:57	40m	- / -	HB9ELE	+5 / -	5	Partial capture
09-22 20:53	40m	- / -13	9A5CW	+13 / -	5	✓ Closing fragment
09-22 20:53	40m	- / -	MI7XHT	-7 / -	3	Partial capture
09-21 20:48	160m	- / -19	DL1RWN	+6 / -	2	Partial capture
09-15 21:13	40m	- / -19	PI4DX	+9 / -	3	✓ Closing fragment

Recent FT8 messages decoded at SO8OO

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

160m

UTC    dB Audio  Message
204800  +6 2644  JA4HDO DL1RWN -19 (x2)
205300  -6  711  JA4HDO UB3IBG -11 (x2)
210530  -8  319  JA4HDO 4J3DJ -18 (x2)

40m

UTC    dB Audio  Message
214100  -7 2719  JA4HDO MI7XHT IO64 (x2)
214300  -3  936  JA4HDO HB9ELE JN47 (x3)
214430  -3 1982  JA4HDO UF5F KO98
214430  -8  936  JA4HDO HB9ELE R-24
214500 -13 1982  JA4HDO UF5F KO98
214500  -3  936  JA4HDO HB9ELE 73
214530  -9 1982  JA4HDO UF5F KO98 (x4)
211430 +17  607  JA4HDO 5B4AMM RR73
212600 -17 1617  JA4HDO IU8RFW JN70

CW

No CW receptions recorded for this callsign in the last 30 days.

Explore CW reception at SO8OO

FT8DB and SO8OO WebSDR are a hobby project maintained solo. ☕ Buy me a coffee