Confidence: Medium · Source: FCC ULS · As of 2026-09-12
KO4SH callsign genealogy
Currently held by DONALDSON, WILLIAM 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 KO4SH's current licensee, walking backwards.
- N4STDno FCC ULS record on file
Successor callsigns
Callsigns held now by people who previously held KO4SH.
No current licensee on record previously held this callsign.