Confidence: Medium · Source: FCC ULS · As of 2026-09-12
KO3Z callsign genealogy
Currently held by Nace, John 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 KO3Z's current licensee, walking backwards.
Successor callsigns
Callsigns held now by people who previously held KO3Z.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign KO3Z, oldest first.
- Nace, John H PA2007-12-20 → cancelled 2020-02-21
- WALTMAN, TODD J PA2020-03-13 active