S21SDR — FT8 activity observed at SO8OO

DXCC entity inferred from callsign: Bangladesh Locator transmitted in a decoded message: NL53

Receiver-side FT8 activity involving S21SDR, decoded by SO8OO in southeastern Poland. 728 related FT8 messages, 3 CQ messages, observed on 80m, 40m, 20m, 10m, across 42 UTC dates. Heard between 2026-06-07 and 2026-08-22.

These are automated observations at the SO8OO receiver, not the station's official logbook. Times are UTC. Decoder S/N describes messages received at SO8OO; inferred entity and location data may be inaccurate for portable, remote or special-event operation.

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Overview

728

Related messages

CQ messages

UTC dates heard

-7 dB

Mean decoder S/N

Bands

80m 20m 40m 10m

First seen: 2026-06-07
Last seen: 2026-08-22 15:20 UTC

Frequent QSO partners observed at SO8OO

Stations S21SDR worked most often, as logged from our receiver:

RA3QUA · European Russia ×2 DK2LG · Fed. Rep. of Germany UR5ZHJ · Ukraine UA3GDJ · European Russia DL70ESSEN · Fed. Rep. of Germany UR1CCT · Ukraine E21AZ · Thailand LB1R · Norway M0BCT · England YO8PS · Romania DH1FA · Fed. Rep. of Germany RV6AVU · European Russia

Activity Heatmap

Locator transmitted by S21SDR

Approximate centre of NL53, decoded 2026-07-09 18:52 UTC. A transmitted locator is not proof of the operator's permanent location.

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	S21SDR S/N	Counterpart	Counterpart S/N	Msgs	Capture
08-18 18:00	40m	- / -15	DM5KM	+6 / -	4	Partial capture
08-18 17:57	40m	- / -	YO7ARZ	-7 / -	6	Partial capture
08-18 17:56	40m	- / -18	LB7ZG	-11 / -	4	Partial capture
08-18 17:56	40m	- / -15	RM5F	-5 / -	5	✓ Closing fragment
08-18 17:56	40m	- / -19	SP7IIT	-8 / -	7	✓ Closing fragment
08-15 16:06	40m	- / -14	UA3GDJ	-10 / -	2	✓ Closing fragment
08-11 16:21	20m	- / -	DL1R	0 / -	6	Partial capture
08-11 16:20	20m	- / -	IU4PSX	+2 / -	6	Partial capture
08-11 16:20	20m	- / -11	M0BCT	+2 / -	2	✓ Closing fragment
08-10 20:49	20m	- / -17	PE2AE	-8 / -	3	Partial capture
08-10 16:25	40m	- / -	SM0EUI	-15 / -	2	✓ Closing fragment
08-10 16:25	40m	- / -5	UR1CCT	+1 / -	2	✓ Closing fragment
08-09 19:08	20m	- / -19	TA1CCM	-19 / -	2	✓ Closing fragment
08-09 16:16	20m	- / -12	F8FUA	-6 / -	3	Partial capture
08-09 16:14	20m	- / -	DL8TV	+3 / -	3	✓ Closing fragment
08-09 16:04	40m	- / -	UR1CCT	+9 / -	2	Partial capture
08-09 15:01	20m	- / -	ON4CBK	-21 / -	3	Partial capture
08-09 14:50	20m	- / -	DG7JG	-16 / -	6	Partial capture
08-03 17:58	20m	- / -6	MD0CCE	-16 / -	2	✓ Closing fragment
08-03 17:56	20m	- / -	PD1ADA	-14 / -	6	Partial capture
08-02 19:18	40m	- / -	RY7F	-9 / -	2	Partial capture
07-30 20:51	40m	- / -	SP2LLP	-8 / -	8	Partial capture
07-30 20:49	40m	- / -	UW5KW	-10 / -	5	Partial capture
07-30 20:47	40m	- / -13	SM7DXE	-4 / -	3	✓ Closing fragment
07-30 20:44	40m	- / -23	RA3ZH	-20 / -	2	Partial capture
07-30 19:54	20m	- / -	F4NGR	-15 / -	5	Partial capture
07-30 19:53	20m	- / -	IZ2EID	-2 / -	20	Partial capture
07-30 19:44	80m	- / -19	UA4FKT	+12 / -	3	✓ Closing fragment
07-30 17:11	20m	- / -14	DL2RH	-8 / -	2	✓ Closing fragment
07-29 18:50	20m	- / -	GW5GDP	-15 / -	3	Partial capture
07-29 18:45	20m	- / -	IU1LCK	+2 / -	2	Partial capture
07-22 19:45	40m	- / -17	US2UM	-7 / -	3	Partial capture
07-22 19:43	40m	- / -23	DD7EE	-4 / -	5	✓ Closing fragment
07-22 19:43	40m	- / -25	DK7ZT	-20 / -	3	Partial capture
07-22 15:41	20m	- / -10	E21AZ	-2 / -	4	✓ Closing fragment
07-20 20:03	80m	- / -	UA4FKT	+8 / -	2	Partial capture
07-20 19:58	40m	- / -	UA9CR	-13 / -	2	✓ Closing fragment
07-20 19:55	40m	- / -	S51DD	-5 / -	3	Partial capture
07-20 19:55	40m	- / -	RK3IR	-12 / -	4	Partial capture
07-20 19:54	40m	- / -	SP2FWC	+7 / -	7	Partial capture
07-20 19:54	40m	- / -24	SP5CJY	-16 / -	2	Partial capture
07-20 18:26	20m	- / -18	YO9CX	-16 / -	2	✓ Closing fragment
07-20 18:24	20m	- / -15	UA3SNB	-10 / -	2	✓ Closing fragment
07-18 19:10	20m	- / -22	PD0BOR	-11 / -	3	Partial capture
07-17 16:31	20m	- / -	F1PFU	-17 / -	3	Partial capture
07-17 16:29	20m	- / -	MI9PBM	+2 / -	3	Partial capture
07-16 16:30	20m	- / -7	RV6AVU	-8 / -	2	✓ Closing fragment
07-16 16:26	20m	- / -	RV6AVU	-5 / -	3	Partial capture
07-16 16:25	20m	- / -	EA5AOP	-16 / -	3	Partial capture
07-16 16:25	20m	- / -	UA6UEU	-16 / -	3	Partial capture

Recent FT8 messages decoded at SO8OO

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

20m

UTC    dB Audio  Message
162145  +3 2673  S21SDR DL1R JN58
162145  +5 2127  S21SDR IU4PSX JN54 (x2)
162245  -2 2673  S21SDR DL1R JN58
162245  +2 2127  S21SDR IU4PSX JN54
162315  -1 2673  S21SDR DL1R JN58
162315  +6 2127  S21SDR IU4PSX JN54
162415  -4 2673  S21SDR DL1R JN58
162415  -5 2103  S21SDR IU4PSX JN54
162445  +5 2673  S21SDR DL1R JN58
163045 -16 1780  S21SDR R4HLO LO43
154100 -18 2119  S21SDR BA5CW R-08
162815 -12  641  S21SDR R2AL KO85
171915  +4 1768  S21SDR IK4RUX JN54
172015 -17 1176  S21SDR RY3F RR73

10m

UTC    dB Audio  Message
122045  -5  633  S21SDR GJ0KYZ IN89
100715 -16 1976  S21SDR IW6MXV JN72

40m

UTC    dB Audio  Message
175815  -6  433  S21SDR RM5F KO85
175815  -6  360  S21SDR YO7ARZ KN14
175815  -9 2254  S21SDR SP7IIT R-19
175845  -7  360  S21SDR YO7ARZ KN14
175845  -4  433  S21SDR RM5F R-15 (x2)
175915  -6 2254  S21SDR SP7IIT R-19
175915 -10  359  S21SDR YO7ARZ KN14
175945  -7 2254  S21SDR SP7IIT 73
175945 -10  360  S21SDR YO7ARZ KN14 (x2)
180045  +8  358  S21SDR DM5KM -15 (x4)

80m

UTC    dB Audio  Message
185100 -18 2141  CQ S21SDR NL53                        a1
185115 +10 2140  S21SDR SA5ACL JO78
185130 -18 2141  CQ S21SDR NL53
185145 +10 2645  S21SDR HF5A JO92
185145  +6 2140  S21SDR SA5ACL JO78
185200 -17 2141  CQ S21SDR NL53
185215 -15 1948  S21SDR RN6LDK KN96
185215  +3 2140  S21SDR SA5ACL JO78 (x3)
200315 +11  516  S21SDR UA4FKT LO23 (x5)

Decoder S/N history by band

Daily averages across messages associated with this profile as decoded at SO8OO.