Confidence: Medium · Source: FCC ULS · As of 2026-09-12
KU5X callsign genealogy
Currently held by Mason, Michael R
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 KU5X's current licensee, walking backwards.
Successor callsigns
Callsigns held now by people who previously held KU5X.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign KU5X, oldest first.
- BOSANKO, GLEN A WI1996-09-16 → cancelled 2003-03-27
- Mason, Michael R CO2023-02-24 active