RA3ZDU — FT8 activity observed at SO8OO

DXCC entity inferred from callsign: European Russia Most frequent locator attributed to this token: KO90

Receiver-side FT8 activity involving RA3ZDU, decoded by SO8OO in southeastern Poland. 3,182 FT8 messages attributed to this token as transmitter, on 160m, 80m, 40m, 20m, 10m, across 51 UTC dates in the available aggregate history. Observed between 2026-06-06 and 2026-09-19.

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 3,182 FT8 messages attributed to RA3ZDU as the transmitting token by decoded message structure across 51 UTC dates in the available aggregate history. The largest monitored-band total was 20 m (50%), followed by 40 m (36%) and 10 m (11%). The busiest six-hour window was 00:00-06:00 UTC, containing 39% of decodes. Received S/N was mixed across SO8OO's weak, moderate and strong ranges; the estimated median was -8.2 dB.

Overview

3,182

Messages attributed

UTC dates decoded

318

Active 15-min windows

-8.2 dB

Estimated median S/N

Bands

160m · 3 80m · 109 40m · 1,152 20m · 1,581 10m · 337

First attributed message: 2026-06-06
Last attributed message: 2026-09-19 03:09 UTC

Observed FT8 message patterns

Attributed sample: 3,182 messages
Active dates: 51 UTC dates
Estimated median S/N: -8.2 dB
Estimated 10th-90th percentile: -18.5 to +4 dB
Recurring-pattern threshold: Met

SO8OO display ranges among successful decodes: weak (≤ -16 dB) 647, moderate (-15 to -9 dB) 928, strong (≥ -8 dB) 1,607.

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 RA3ZDU in decoded directed-looking exchanges:

F1IQH · France ×3 G4SRT · England ×2 IZ2CPO/QRP · Italy ×2 LA8OKA · Norway ×2 LZ6C · Bulgaria ×2 M3WHB · England ×2 ON8PB · Belgium ×2 RO6G · European Russia ×2 S51WB · Slovenia ×2 YO3RU · Romania ×2 YT3MD · Serbia ×2 RA4ADF · European Russia ×2

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 RA3ZDU

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: KO90 · 2,146 decoded messages
SO8OO receiver locator: KN09VW
Locator-centre separation: 1,223 km (approx.)
Last such locator decoded: 2026-09-19 03:09 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	RA3ZDU S/N	Counterpart	Counterpart S/N	Msgs	Capture
09-19 03:11	40m	- / -12	MI7XHT	-8 / -	3	Partial capture
09-19 03:08	40m	+3 / -15	CT2HEX	-11 / -4	5	✓ Full exchange observed
09-19 03:05	40m	-5 / -	EB1LA	- / -	2	Partial capture
09-19 03:03	40m	-9 / -	EA4IPN	- / -	3	Partial capture
09-19 03:02	40m	-6 / -	MI7XHT	- / -	2	Partial capture
09-19 03:01	40m	-5 / -1	EA8BS	-11 / -1	6	✓ Full exchange observed
09-19 02:59	40m	+4 / -	OA4ENG	- / -	3	Partial capture
09-19 02:54	40m	0 / -	NP4EB	- / -6	5	Partial capture
09-19 02:53	40m	+6 / +5	R4HNW	-5 / +3	6	✓ Full exchange observed
09-19 02:52	40m	+8 / -	LU1AW	- / -	2	Partial capture
09-19 02:51	40m	-2 / -15	TA5DOB	-15 / -2	5	✓ Full exchange observed
09-19 02:49	40m	0 / -	OT7K	- / -7	4	✓ Closing fragment
09-19 02:48	40m	+18 / -	DL3SC	- / -	2	Partial capture
09-19 02:47	40m	+12 / -	9Z4S	- / -	2	Partial capture
09-19 02:36	40m	- / -15	EA5GKL	-17 / -	2	✓ Closing fragment
09-19 02:30	40m	- / -19	RC6ZB	+17 / -	2	✓ Closing fragment
09-19 01:48	40m	- / -14	RW9WT	-12 / -	2	✓ Closing fragment
09-19 01:02	40m	- / -21	PT7YV	+4 / -	2	✓ Closing fragment
09-19 00:49	40m	- / -22	R1ZBR	-8 / -	3	✓ Closing fragment
09-15 04:07	40m	-6 / -8	R1QF/P	-20 / -3	2	Partial capture
09-15 03:18	40m	+10 / -	N3LAG	- / -	2	Partial capture
09-15 03:17	40m	+8 / -	YV5KG	- / -	2	Partial capture
09-15 03:15	40m	+2 / -	KC4DPT	- / -	4	Partial capture
09-05 07:34	40m	- / -17	SN40KZE	+10 / -	2	Partial capture
09-05 06:04	40m	-10 / -	SQ8V	- / -	6	Partial capture
09-05 06:01	40m	-14 / -	R6OBN	-15 / -15	3	✓ Closing observed
09-05 05:59	40m	-10 / -16	S57NCP	+4 / -	3	✓ Closing observed
09-05 05:53	40m	-10 / -	SQ8V	- / -	4	Partial capture
09-05 05:48	40m	-17 / -	R3BIS	- / 0	3	✓ Closing fragment
09-05 05:44	40m	- / -2	RA6SA	-7 / -	2	✓ Closing fragment
09-05 05:41	40m	- / +6	R3DIH	-4 / -	2	Partial capture
09-05 05:40	40m	-5 / -	PE2LRT	- / -	2	Partial capture
09-05 05:37	40m	-18 / -	SP9IZV	- / -	2	Partial capture
09-05 05:31	40m	-7 / -	PE2LRT	- / -	2	Partial capture
09-05 05:28	40m	-12 / -	RA3V	- / -10	2	✓ Closing fragment
09-05 05:25	40m	-16 / -	DJ6OI	- / -	2	Partial capture
09-05 04:36	40m	-9 / -8	SP9KDA	-15 / -	2	✓ Closing observed
09-05 03:54	40m	-6 / +4	R73SLET	-11 / 0	3	Partial capture
09-05 03:53	40m	-6 / -	OA4ENG	- / -	2	Partial capture
09-05 03:51	40m	-8 / -	EG3PDA	-14 / -18	3	✓ Closing observed
09-05 01:54	40m	- / -8	SO100PKP	-13 / -	2	Partial capture
09-05 01:27	40m	- / -9	RA9LT	-2 / -	2	✓ Closing fragment
09-03 00:12	40m	+2 / -10	AC2PB	-3 / -7	5	✓ Full exchange observed
09-03 00:06	40m	-5 / -	DH8KAM	- / -	8	Partial capture
08-30 08:56	20m	+10 / -	DL4DD	- / -	2	Partial capture
08-30 08:54	20m	+1 / -	PD5URK	- / -	4	Partial capture
08-30 08:46	20m	+3 / -	OH/DG2SBL	-7 / +1	6	Partial capture
08-30 08:44	20m	-4 / -10	OE9NET	-18 / -	3	✓ Closing observed
08-30 08:42	20m	-6 / -	PD4AVT	-10 / -14	4	✓ Closing observed
08-30 08:41	20m	-6 / +9	F4IOH/P	+13 / -	3	Partial capture

Recent FT8 messages decoded at SO8OO

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

40m

UTC    dB Audio  Message
030515  +5 2579  OH/DL4XT RA3ZDU KO90
030545  -5 1471  EB1LA RA3ZDU KO90 (x2)
030645  -5 1471  CQ RA3ZDU KO90 (x3)
030800 -10 2249  RA3ZDU CT2HEX IM58
030815  +3 2250  CT2HEX RA3ZDU -04
030830 -11 2250  RA3ZDU CT2HEX R-15
030845  +3 2250  CT2HEX RA3ZDU RR73
030900 -11 2250  RA3ZDU CT2HEX 73
030915  +0 1009  HB9BWE RA3ZDU KO90
031100  -9 1047  RA3ZDU MI7XHT -12 (x3)

20m

UTC    dB Audio  Message
084630  +5 2803  OH/DG2SBL RA3ZDU KO90 (x3)
084845  -7 2803  RA3ZDU OH/DG2SBL +20
084900  +5 2803  OH/DG2SBL RA3ZDU R+01
085445  +1 2167  PD5URK RA3ZDU KO90 (x4)
085645  +8 2636  DL4DD RA3ZDU KO90 (x2)
085745  +6 2257  HA/G4RCR RA3ZDU KO90
085830  -8 1986  RA3ZDU F4IOH/P +10
085945  +1  896  II4KEMP RA3ZDU KO90
090115  +5 2354  IK0XBU/P RA3ZDU R+03

80m

UTC    dB Audio  Message
004315  +3 1582  <...> RA3ZDU KO90
004330 -13 1582  RA3ZDU <...> +19
004345  +1 1582  <...> RA3ZDU R-04
004500  -7 1500  IZ5HLP RA3ZDU KO90
004515  -7 1499  RA3ZDU IZ5HLP -14
004530  -7 1499  IZ5HLP RA3ZDU R-11
004545  -8 1499  RA3ZDU IZ5HLP RRR
004600 -10 1499  IZ5HLP RA3ZDU 73
004615  -6 1499  RA3ZDU IZ5HLP 73
004645  +0 1755  OK1AMF RA3ZDU KO90
004700  +4 1755  RA3ZDU OK1AMF -06
004715  +2 1755  OK1AMF RA3ZDU R-03
004730  +1 1755  RA3ZDU OK1AMF RR73
004745  +0 1755  OK1AMF RA3ZDU 73
004845  +5 2270  LY1DY RA3ZDU KO90

10m

UTC    dB Audio  Message
055345  -8  960  LZ3XM RA3ZDU KO90 (x3)
155715 -15 2416  RV9CME RA3ZDU 73
163145  -6 1508  RA3ZDU LZ2OG RR73
164615 -24 1459  RA3ZDU R7RAE RRR
170145 -13 1550  RA3ZDU DH4PAP -13 (x5)
171315  +5 2580  RA3ZDU DN9PBN +00 (x3)
082700 -24 1873  RA3ZDU R2BKT -09

160m

UTC    dB Audio  Message
191530 -17 1312  RA3ZDU R2EA/P +00 (x3)
192045 -22 1312  R2EA/P RA3ZDU R+01
192100 -16 1312  RA3ZDU R2EA/P RR73

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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