Confidence: Medium · Source: FCC ULS · As of 2026-09-12
WS9O callsign genealogy
Currently held by Walder, Stephan
The FCC publishes a previous_call_sign on
every amateur license — a self-link to the licensee's prior callsign.
Following those links produces the chain below.
Previous callsigns
Older callsigns held by WS9O's current licensee, walking backwards.
Successor callsigns
Callsigns held now by people who previously held WS9O.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign WS9O, oldest first.
- BEATTY, WALTER E IN2000-03-03 → cancelled 2002-01-27
- Walder, Stephan NC2025-11-20 active