Confidence: Medium · Source: FCC ULS · As of 2026-09-12
N1OSU callsign genealogy
Currently held by MULLEN, JOHN 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 N1OSU's current licensee, walking backwards.
- WALTON, ERIC LOHgranted 2012-11-15cancelled 2015-11-21
Successor callsigns
Callsigns held now by people who previously held N1OSU.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign N1OSU, oldest first.
- MULLEN, JOHN J MA1993-03-23 → cancelled 2005-03-24
- Walton, Eric L OH2015-11-21 active