Confidence: Medium · Source: FCC ULS · As of 2026-09-12
W1PRO callsign genealogy
Currently held by O BRIEN III, WILLIAM H
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 W1PRO's current licensee, walking backwards.
- O BRIEN III, WILLIAM Hcancelled 1998-12-09
Successor callsigns
Callsigns held now by people who previously held W1PRO.
No current licensee on record previously held this callsign.