Confidence: Medium · Source: FCC ULS · As of 2026-09-12
KO1Z callsign genealogy
Currently held by DORNFELD, ROBERT 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 KO1Z's current licensee, walking backwards.
Successor callsigns
Callsigns held now by people who previously held KO1Z.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign KO1Z, oldest first.
- DORNFELD, ROBERT J FL2008-12-04 → cancelled 2018-05-20
- Koziy, Robert J MN2020-06-09 active