Confidence: Medium · Source: FCC ULS · As of 2026-09-12
NI4O callsign genealogy
Currently held by Stewart, Mary J
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 NI4O's current licensee, walking backwards.
- Stewart, Mary JFLgranted 2003-11-05cancelled 2007-03-17
Successor callsigns
Callsigns held now by people who previously held NI4O.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign NI4O, oldest first.
- PETREE, ISAAC C TN1995-11-28 → cancelled 1998-06-10
- Stewart, Mary J FL2017-01-21 active