Confidence: Medium · Source: FCC ULS · As of 2026-09-14
KO4RDJ callsign genealogy
Currently held by ZAJAC, JOSEPH M
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 KO4RDJ's current licensee, walking backwards.
The current licensee has not held any other callsign on record.
Successor callsigns
Callsigns held now by people who previously held KO4RDJ.
- ZAJAC, JOSEPH MNCgranted 2021-06-29