Confidence: Medium · Source: FCC ULS · As of 2026-09-14
KO4DXR callsign genealogy
Currently held by Holleman, Matthew 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 KO4DXR'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 KO4DXR.
- Holleman, Matthew JGAgranted 2020-07-28cancelled 2022-01-08