Confidence: Medium · Source: FCC ULS · As of 2026-09-12
K4MBX callsign genealogy
Currently held by BUTLER, MICHAEL 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 K4MBX's current licensee, walking backwards.
- BUTLER, MICHAEL JNCgranted 2018-04-06cancelled 2018-04-27
Successor callsigns
Callsigns held now by people who previously held K4MBX.
No current licensee on record previously held this callsign.