KC3SDJ — FT8 activity observed at SO8OO

DXCC entity inferred from callsign: United States Most frequent locator attributed to this token: EN90

Receiver-side FT8 activity involving KC3SDJ, decoded by SO8OO in southeastern Poland. 27 FT8 messages attributed to this token as transmitter, on 40m, 20m, across 4 UTC dates in the available aggregate history. Observed between 2026-08-25 and 2026-09-10.

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 27 FT8 messages attributed to KC3SDJ as the transmitting token by decoded message structure across 4 UTC dates in the available aggregate history. The largest monitored-band total was 20 m (89%), followed by 40 m (11%). Several six-hour UTC windows tied for the largest share (67%), so no unique busiest interval is claimed. Received S/N was mixed across SO8OO's weak, moderate and strong ranges; the estimated median was -13 dB.

Overview

Messages attributed

UTC dates decoded

Active 15-min windows

-13 dB

Estimated median S/N

Bands

40m · 3 20m · 24

First attributed message: 2026-08-25
Last attributed message: 2026-09-10 05:05 UTC

Observed FT8 message patterns

Attributed sample: 27 messages
Active dates: 4 UTC dates
Estimated median S/N: -13 dB
Estimated 10th-90th percentile: -24 to -2 dB
Recurring-pattern threshold: Met

SO8OO display ranges among successful decodes: weak (≤ -16 dB) 9, moderate (-15 to -9 dB) 11, strong (≥ -8 dB) 7.

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 KC3SDJ in decoded directed-looking exchanges:

EB3CGQ · Spain F1PBZ · France F4HSB · France F5IXN · France IK4LZH · Italy PD1ADA · Netherlands RY7F · European Russia TN8GD · Republic of the Congo UW8SM · Ukraine ZL1VAH · New Zealand 4X5MZ · Israel DF5KX · Fed. Rep. of Germany

Most frequent locator attributed to KC3SDJ

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: EN90 · 5 decoded messages
SO8OO receiver locator: KN09VW
Locator-centre separation: 7,464 km (approx.)
Last such locator decoded: 2026-09-07 06:37 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	KC3SDJ S/N	Counterpart	Counterpart S/N	Msgs	Capture
09-21 06:16	40m	- / -9	F5NBU	+2 / -	3	✓ Closing fragment
09-21 06:16	40m	- / -10	F6FTB	-4 / -	5	✓ Closing fragment
09-10 05:08	40m	- / -	E75FM	-4 / -	9	Partial capture
09-10 05:06	40m	- / -13	R7DX	+6 / -	4	✓ Closing fragment
09-10 04:45	40m	- / -	E75FM	-1 / -	4	Partial capture
09-10 04:45	40m	- / -	IZ8XJJ	-10 / -	2	Partial capture
09-07 06:56	40m	- / -	IN3LTL	-10 / -	2	Partial capture
09-07 06:53	40m	- / -	F1BHB	-20 / -	2	Partial capture
09-07 06:52	40m	- / -19	DK4RH	-19 / -	3	✓ Closing fragment
09-07 06:42	40m	- / -	F4LZZ	-16 / -	2	Partial capture
09-07 06:41	40m	- / -	DL6LG	-7 / -	2	Partial capture
09-07 06:41	40m	- / -	9A4ZM	+2 / -	2	Partial capture
09-07 06:38	40m	- / -11	DG2EBG	-18 / -	4	Partial capture
09-07 06:38	40m	- / -4	PD0WL	-4 / -	2	✓ Closing fragment
09-07 06:36	40m	- / -	F4NJT	-17 / -	6	Partial capture
09-07 06:33	40m	- / -	DL6LG	-7 / -	2	Partial capture
09-07 06:31	40m	- / -	G0BLB	-6 / -	4	✓ Closing fragment
09-07 06:28	40m	- / -9	DF5KX	-11 / -	14	✓ Closing fragment
09-07 06:27	40m	- / -3	DL1EMV	-8 / -	7	✓ Closing fragment
09-07 06:27	40m	-24 / -3	F4EMG	-1 / -	4	✓ Closing observed
09-02 05:20	80m	- / -7	F6CTT	-4 / -	2	✓ Closing fragment
08-31 05:43	40m	- / -	IU1TLG	-20 / -	2	Partial capture
08-31 05:42	40m	- / -	DL3LBK	-12 / -	2	Partial capture
08-31 05:36	40m	- / -8	DL9KM	-3 / -	3	✓ Closing fragment
08-31 05:35	40m	- / -11	F4JZW	-5 / -	3	✓ Closing fragment
08-31 05:34	40m	- / -5	OK5AG	+5 / -	3	✓ Closing fragment
08-31 05:30	40m	- / -9	DL3OCF	+9 / -	3	✓ Closing fragment
08-31 05:25	80m	- / -6	F4GTB	-16 / -	2	✓ Closing fragment
08-31 05:22	80m	- / -	DO1BWS	-22 / -	2	Partial capture
08-31 05:19	80m	- / +1	F5NLY	-21 / -	3	✓ Closing fragment
08-31 05:16	80m	- / -	F4BYA	+1 / -	5	Partial capture
08-27 07:03	40m	- / -	F1IQH	-18 / -	2	Partial capture
08-27 06:47	20m	-18 / -6	F5IXN	+1 / -10	5	✓ Full exchange observed
08-27 06:45	20m	-22 / -7	RY7F	0 / -17	5	✓ Full exchange observed
08-27 06:44	20m	- / -	IT9LCC	-15 / -	5	Partial capture
08-27 06:38	20m	- / -	ON4JPE	+4 / -	2	Partial capture
08-27 06:38	20m	- / -5	PD1ADA	-4 / -	3	✓ Closing fragment
08-26 06:01	20m	- / -	ZL1VAH	-14 / -	2	✓ Closing fragment
08-26 05:29	40m	- / -	F4BYA	-13 / -	3	Partial capture
08-26 05:29	40m	- / -13	PA1PXL	-9 / -	2	Partial capture
08-25 21:42	20m	-10 / -	PD0DDA	- / -6	2	Partial capture
08-25 21:41	20m	-12 / -	TJ1GD	- / -	2	Partial capture
08-25 21:37	20m	-7 / -	SP5XMD	- / -11	5	Partial capture
08-25 21:35	20m	-4 / -	UW8SM	- / -	2	✓ Closing fragment
08-25 21:32	20m	-13 / +7	IK4LZH	-14 / +8	3	✓ Full exchange observed
08-04 03:32	40m	- / -	LZ3RG	-22 / -	4	Partial capture
07-25 05:59	20m	- / -	LZ3BS	0 / -	2	Partial capture
07-17 05:19	40m	- / +2	F4GWG	-20 / -	2	Partial capture
07-15 05:58	40m	- / -	F4FRC	-21 / -	2	Partial capture
07-13 19:50	20m	- / -	MM0UIO	-8 / -	5	Partial capture

Recent FT8 messages decoded at SO8OO

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

40m

UTC    dB Audio  Message
051000  -6 2909  KC3SDJ E75FM JN93
051030 -17 1291  KC3SDJ YO6QDY KN26
051030  -6 2909  KC3SDJ E75FM JN93 (x5)
061645  -2 2398  KC3SDJ F6FTB JN27
061645  +2 1331  KC3SDJ F5NBU JN28
061715  -3 2398  KC3SDJ F6FTB JN27
061715  +1 1331  KC3SDJ F5NBU R-09
061745  -5 2398  KC3SDJ F6FTB JN27
061745  +4 1331  KC3SDJ F5NBU 73
061815  -2 2397  KC3SDJ F6FTB R-10 (x2)

80m

UTC    dB Audio  Message
051630  +5 2810  KC3SDJ F4BYA JN19 (x3)
051900 -22 1822  KC3SDJ F5NLY JN08 (x2)
051930  +0 2809  KC3SDJ F4BYA JN19
052000 -19 1821  KC3SDJ F5NLY 73
052230 -11 1713  KC3SDJ F4GTB JN18
052230 -24 1566  KC3SDJ DO1BWS JO53 (x2)
052530 -14 1713  KC3SDJ F4GTB R-06 (x2)
052730  -4 2809  KC3SDJ F4BYA JN19
052045  -2 2603  KC3SDJ F6CTT -07 (x2)

20m

UTC    dB Audio  Message
064545 -17  547  KC3SDJ IT9LCC JM78
064600 -21 1044  RY7F KC3SDJ RR73
064615  +3 2421  KC3SDJ RY7F 73
064615 -15  547  KC3SDJ IT9LCC JM78 (x3)
064715  -3 1045  KC3SDJ F5IXN JN23
064715 -12 1746  KC3SDJ F4HSB 73
064730 -18 1044  F5IXN KC3SDJ -10
064745  +4 1045  KC3SDJ F5IXN R-06
064800 -17 1044  F5IXN KC3SDJ RR73
064815  +2 1045  KC3SDJ F5IXN 73
064915 +16  675  KC3SDJ F1PBZ RR73
064945  -5 1209  KC3SDJ F1IQH JN27
065015  +6 1043  KC3SDJ PD0DDA JO22

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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