4X5JK — FT8 activity observed at SO8OO

DXCC entity inferred from callsign: Israel Most frequent locator attributed to this token: KM71

Receiver-side FT8 activity involving 4X5JK, decoded by SO8OO in southeastern Poland. 1,415 FT8 messages attributed to this token as transmitter, on 80m, 60m, 40m, 20m, across 37 UTC dates in the available aggregate history. Observed between 2026-06-07 and 2026-09-06.

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 1,415 FT8 messages attributed to 4X5JK as the transmitting token by decoded message structure across 37 UTC dates in the available aggregate history. The largest monitored-band total was 40 m (49%), followed by 20 m (23%) and 60 m (18%). Most decodes (78%) fell within the six-hour window 18:00-00:00 UTC. Received S/N was mixed across SO8OO's weak, moderate and strong ranges; the estimated median was -13 dB.

Overview

1,415

Messages attributed

UTC dates decoded

173

Active 15-min windows

-13 dB

Estimated median S/N

Bands

80m · 140 60m · 252 40m · 699 20m · 324

First attributed message: 2026-06-07
Last attributed message: 2026-09-06 19:05 UTC

Observed FT8 message patterns

Attributed sample: 1,415 messages
Active dates: 37 UTC dates
Estimated median S/N: -13 dB
Estimated 10th-90th percentile: -19.4 to -5 dB
Recurring-pattern threshold: Met

SO8OO display ranges among successful decodes: weak (≤ -16 dB) 423, moderate (-15 to -9 dB) 678, strong (≥ -8 dB) 314.

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 4X5JK in decoded directed-looking exchanges:

IK4LZH · Italy ×3 R3DQK · European Russia ×2 DF8RU · Fed. Rep. of Germany ×2 DJ9BI · Fed. Rep. of Germany ×2 SM7JKW · Sweden ×2 IK1MJK/P · Italy ×2 RV3X · European Russia ×2 UB3KET · European Russia ×2 LY8O · Lithuania ×2 RN5AA · European Russia PA4G · Netherlands G0AGT · England

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 4X5JK

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: KM71 · 938 decoded messages
SO8OO receiver locator: KN09VW
Locator-centre separation: 2,325 km (approx.)
Last such locator decoded: 2026-09-06 19:05 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	4X5JK S/N	Counterpart	Counterpart S/N	Msgs	Capture
09-07 21:52	40m	- / -6	RJ6ON	+3 / -	2	✓ Closing fragment
09-07 21:39	40m	- / -10	SY1BKQ	-2 / -	4	✓ Closing fragment
09-07 21:38	40m	- / +3	YO3FRI	-12 / -	3	✓ Closing fragment
09-05 00:52	40m	-4 / -	RI1FJL	- / -5	4	✓ Closing fragment
09-05 00:51	40m	-16 / -	DK5HH	- / -15	2	Partial capture
09-05 00:49	40m	-18 / -	UB3KET	-14 / -13	3	✓ Closing observed
09-04 19:20	160m	- / -	SP2LLP	-2 / -	6	Partial capture
09-04 19:13	160m	- / -	SP2LLP	0 / -	6	Partial capture
09-04 18:57	160m	- / -	SP2LLP	-5 / -	3	Partial capture
08-31 22:52	40m	-18 / -	DL2DT	-9 / -	3	✓ Closing observed
08-31 22:47	40m	-10 / -	F4MBU	- / -5	2	✓ Closing fragment
08-31 22:41	40m	-8 / -	OH1ZE	- / -10	2	✓ Closing fragment
08-31 22:34	40m	-10 / -	PW8BR	- / -	9	Partial capture
08-31 20:43	40m	- / -6	S59YL	-6 / -	3	✓ Closing fragment
08-31 20:39	40m	-12 / -16	IU0DHV	-12 / -	3	✓ Closing observed
08-31 20:19	40m	-10 / -	OE6GBG	+7 / -13	3	✓ Closing observed
08-31 20:05	40m	- / -5	SP9BEM	0 / -	2	Partial capture
08-31 19:58	40m	- / -	ON5MX	-8 / -	3	Partial capture
08-31 19:55	40m	- / -17	OK2BXD	-8 / -	2	Partial capture
08-31 19:51	40m	- / -12	OK2BXD	-8 / -	3	✓ Closing fragment
08-31 19:43	40m	-10 / -20	F4MVX	-16 / -15	4	Partial capture
08-31 19:33	40m	- / -10	DF8RU	+6 / -	3	✓ Closing fragment
08-31 19:28	40m	- / -13	HB9FUR	-5 / -	3	✓ Closing fragment
08-31 19:01	40m	- / -19	EW2RA	+4 / -	2	✓ Closing fragment
08-31 18:49	40m	-15 / -16	SP5EAF	-8 / -9	3	✓ Full exchange observed
08-31 18:43	40m	- / -	PD1AQL	-10 / -	2	Partial capture
08-31 18:42	40m	- / -11	IK1MJK	-9 / -	3	✓ Closing fragment
08-31 18:29	80m	- / -22	UR3LM	+10 / -	4	✓ Closing fragment
08-31 18:18	80m	- / -	RL3AW	0 / -	2	Partial capture
08-30 22:09	20m	-18 / -12	CT2HSM	-5 / -16	9	✓ Full exchange observed
08-30 22:07	20m	-15 / -	SQ1MNC	+1 / +2	2	Partial capture
08-30 22:05	20m	-17 / -	KB1EFS	-1 / -9	2	✓ Closing observed
08-30 22:00	20m	- / -	CT2HSM	-3 / -	2	Partial capture
08-30 21:34	20m	- / -15	EA1AOC	-3 / -	5	✓ Closing fragment
08-30 21:31	20m	- / 0	IK4LZH	-13 / -	4	✓ Closing fragment
08-30 21:02	20m	+2 / -	YO4GGA	-10 / +6	4	✓ Closing observed
08-30 21:01	20m	- / -8	CT1ADT	-13 / -	2	Partial capture
08-30 20:28	40m	-5 / -	CT7ARQ	- / -	4	Partial capture
08-30 20:13	40m	- / -	HG0GU	-7 / -	2	Partial capture
08-30 19:58	40m	- / -	UR1CDL	-3 / -	2	Partial capture
08-30 19:40	20m	- / -	M6WRB	0 / -	2	Partial capture
08-30 19:34	20m	- / -20	M6WRB	-6 / -	4	Partial capture
08-28 20:13	80m	- / -10	UW2ZO	+8 / -	3	✓ Closing fragment
08-28 20:10	80m	- / -	PE1NAO	-18 / -	2	Partial capture
08-28 20:09	80m	- / -17	OH5KNL	-4 / -	2	Partial capture
08-28 20:07	80m	- / -	DA6IT	-8 / -	3	Partial capture
08-28 19:56	80m	- / -18	UR9QQ	-17 / -	4	Partial capture
08-28 19:41	40m	- / -	YO9ADN	-7 / -	3	Partial capture
08-28 19:38	40m	- / -	R7ZY	+6 / -	2	Partial capture
08-28 19:37	40m	- / +2	OZ1TRP	-12 / -	10	Partial capture

Recent FT8 messages decoded at SO8OO

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

40m

UTC    dB Audio  Message
005515  -5  445  CQ 4X5JK KM71 (x2)
005745 -15 1493  KU3R 4X5JK KM71
005815 -19 1493  CQ 4X5JK KM71
213800 -15 2325  4X5JK YO3FRI KN34 (x2)
213830 -19 2007  4X5JK F4DWE JN18
213900 -11 2325  4X5JK YO3FRI 73
213930  -3 2831  4X5JK SY1BKQ KM18 (x4)
215230  +1 2344  4X5JK RJ6ON -06 (x2)
215400 -13 2342  4X5JK DG5PW JO30

80m

UTC    dB Audio  Message
201315  +7 2125  4X5JK UW2ZO KN67 (x3)
201615  -4 1860  4X5JK YL3BU KO26 (x2)
181815  +3 1293  4X5JK RL3AW KO85 (x2)
182945  +7 2073  4X5JK UR3LM KN89 (x4)
183215  -2 2824  4X5JK IT9XTP JM68
225315  -7 1003  4X5JK W5GRP FN65
190545 -23 2356  CQ 4X5JK KM71
190700  +5  671  4X5JK EW8KO KO42

160m

UTC    dB Audio  Message
185715  -2 2101  4X5JK SP2LLP JO94 (x15)

20m

UTC    dB Audio  Message
220545  -1 2469  4X5JK KB1EFS RR73
220630 -14 2469  CQ 4X5JK KM71
220745  +1 2469  4X5JK SQ1MNC JO73
220800 -15 2469  SQ1MNC 4X5JK +02
220945  -4 2469  4X5JK CT2HSM IN50
221030 -17 2470  CQ 4X5JK KM71
221045  -8 2469  4X5JK CT2HSM IN50
221100 -17 2469  CQ 4X5JK KM71                         a1
221130 -17 2469  CT2HSM 4X5JK -16
221145  -7 2469  4X5JK CT2HSM R-12 (x2)
221300 -18 2469  CT2HSM 4X5JK -16
221315  -4 2469  4X5JK CT2HSM R-11 (x3)

10m

UTC    dB Audio  Message
132730  -1 2637  4X5JK F1PBZ -15
131730 -22 1306  4X5JK RN7B R-16

60m

UTC    dB Audio  Message
231045 -12 1583  4X5JK DL2YMG R+07
231100  -9 1583  DL2YMG 4X5JK RR73
231115 -14 1583  4X5JK DL2YMG 73
231130 -13 1583  CQ 4X5JK KM71 (x6)
231415 -10 1582  4X5JK OK1TRJ JN79
231430  -7 1583  OK1TRJ 4X5JK +00
231445  -4 1583  4X5JK OK1TRJ R-10
231530  -6 1583  CQ 4X5JK KM71 (x3)

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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