S21IM — FT8 activity observed at SO8OO

Observed FT8 message patterns

Attributed sample

23 messages

Active dates

2 UTC dates

Estimated median S/N

-19 dB

Estimated 10th-90th percentile

-23 to -15 dB

Recurring-pattern threshold

Not met

SO8OO display ranges among successful decodes: weak (≤ -16 dB) 19, moderate (-15 to -9 dB) 4, strong (≥ -8 dB) 0.

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 S21IM in decoded directed-looking exchanges:

Most frequent locator attributed to S21IM

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

NL53 · 18 decoded messages

SO8OO receiver locator

KN09VW

Locator-centre separation

6,563 km (approx.)

Last such locator decoded

2026-06-13 15:24 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.

Recent FT8 messages decoded at SO8OO

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

UTC    dB Audio  Message
173745  +1 2538  S21IM ON5RZ JO21 (x12)
184145 -18 2004  S21IM YB6XFI NJ93 (x3)

UTC    dB Audio  Message
220330  +7 2148  S21IM 9A4ZM JN86 (x3)