Confidence: Medium · Source: FCC ULS · As of 2026-09-12
KC9QIO callsign genealogy
Currently held by Olesinski, John S
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 KC9QIO's current licensee, walking backwards.
- Olesinski Jr, John SILgranted 2004-03-17cancelled 2009-08-18
Successor callsigns
Callsigns held now by people who previously held KC9QIO.
No current licensee on record previously held this callsign.