Confidence: Medium · Source: FCC ULS · As of 2026-09-12
KC9JKC callsign genealogy
Currently held by Sladek, John O
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 KC9JKC's current licensee, walking backwards.
- Sladek, John OILgranted 2006-02-16cancelled 2006-05-02
Successor callsigns
Callsigns held now by people who previously held KC9JKC.
- Sladek, John OILgranted 2006-02-16cancelled 2018-02-17