Confidence: Medium · Source: FCC ULS · As of 2026-09-12
W1CJO callsign genealogy
Currently held by Oster, Charles J
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 W1CJO's current licensee, walking backwards.
- Oster, Charles JILgranted 2014-05-01cancelled 2014-05-20
Successor callsigns
Callsigns held now by people who previously held W1CJO.
No current licensee on record previously held this callsign.