Confidence: Medium · Source: FCC ULS · As of 2026-09-14
KC4SJW callsign genealogy
Currently held by Mason, Jeffrey A
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 KC4SJW's current licensee, walking backwards.
- Mason, Jeffrey AFLgranted 2020-05-14cancelled 2020-06-02
Successor callsigns
Callsigns held now by people who previously held KC4SJW.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign KC4SJW, oldest first.
- KELLER, JEFFREY L NC1990-08-07 → cancelled 2002-08-08
- Mason, Jeffrey A FL2020-06-02 active