Confidence: Medium · Source: FCC ULS · As of 2026-09-12
N4SDF callsign genealogy
Currently held by EARNEST, CHARLES B
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 N4SDF's current licensee, walking backwards.
- KI4WMBcancelledTHE CHARLES E KILBOURNE MEMORIAL AMATEUR RADIO SOCIETYGAgranted 2007-06-14cancelled 2007-07-13
Successor callsigns
Callsigns held now by people who previously held N4SDF.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign N4SDF, oldest first.
- EARNEST, CHARLES B NC1988-02-23 → cancelled 2000-02-24
- THE CHARLES E KILBOURNE MEMORIAL AMATEUR RADIO SOCIETY GA2017-10-27 active