Confidence: Medium · Source: FCC ULS · As of 2026-09-14
KU4OI callsign genealogy
Currently held by DURFIELD, MARK A
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 KU4OI's current licensee, walking backwards.
- KB4BPLcancelledcancelled 1998-02-03
Successor callsigns
Callsigns held now by people who previously held KU4OI.
No current licensee on record previously held this callsign.