Confidence: Medium · Source: FCC ULS · As of 2026-09-12
NF4O callsign genealogy
Currently held by Mahan, John C
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 NF4O's current licensee, walking backwards.
- Mahan, John CALgranted 2019-11-27cancelled 2020-03-31
Successor callsigns
Callsigns held now by people who previously held NF4O.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign NF4O, oldest first.
- JONES, EARLE W FL1996-11-01 → cancelled 2005-11-10
- THATCHER, WILLIAM H FL2008-03-11 → cancelled 2020-03-12
- Mahan, John C AL2020-03-31 active