Confidence: Medium · Source: FCC ULS · As of 2026-09-12
W0OS callsign genealogy
Currently held by Grettum, James A
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 W0OS's current licensee, walking backwards.
- Grettum, James ANDgranted 2006-08-16cancelled 2007-06-26
Successor callsigns
Callsigns held now by people who previously held W0OS.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign W0OS, oldest first.
- HAWKINS, JACK W CO1997-02-24 → cancelled 1998-09-03
- Grettum, James A MN2017-05-19 active