Confidence: Medium · Source: FCC ULS · As of 2026-09-12
K4CSO callsign genealogy
Currently held by OSBORNE, CHARLES 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 K4CSO's current licensee, walking backwards.
- OSBORNE, CHARLES SNCgranted 1996-06-27cancelled 2000-06-17
Successor callsigns
Callsigns held now by people who previously held K4CSO.
No current licensee on record previously held this callsign.