Confidence: Medium · Source: FCC ULS · As of 2026-09-12
WA7OOO callsign genealogy
Currently held by MARWICK, OSPIN B
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 WA7OOO's current licensee, walking backwards.
- MARWICK, OSPINWAgranted 2023-08-01cancelled 2023-10-11
Successor callsigns
Callsigns held now by people who previously held WA7OOO.
- BLUM, WILLIAM RMIgranted 2021-07-24
All historical holders
Every license row we've seen with the callsign WA7OOO, oldest first.
- BLUM, WILLIAM R WA2007-09-11 → cancelled 2011-10-04
- MARWICK, OSPIN B WA2023-10-11 active