Confidence: Medium · Source: FCC ULS · As of 2026-09-14
KU9N callsign genealogy
Currently held by Costello, William 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 KU9N's current licensee, walking backwards.
- Costello, William MILgranted 2013-11-25cancelled 2013-12-14
Successor callsigns
Callsigns held now by people who previously held KU9N.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign KU9N, oldest first.
- SPARKS, LAYTON IN1997-11-14 → cancelled 2009-11-17
- Costello, William M IL2013-12-14 → cancelled 2026-03-07