Confidence: Medium · Source: FCC ULS · As of 2026-09-14
W0IOO callsign genealogy
Currently held by SEIER, WILLIAM D
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 W0IOO's current licensee, walking backwards.
- SEIER, WILLIAM DNEgranted 2007-10-02cancelled 2016-11-08
Successor callsigns
Callsigns held now by people who previously held W0IOO.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign W0IOO, oldest first.
- SEIER, EUGENE H NE2008-03-05 → cancelled 2016-07-25
- SEIER, WILLIAM D NE2016-11-08 active