Confidence: Medium · Source: FCC ULS · As of 2026-09-12
KO4MFS callsign genealogy
Currently held by Sheils, Michael F
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 KO4MFS's current licensee, walking backwards.
- Sheils, Michael FTNgranted 2019-12-03cancelled 2020-01-07
Successor callsigns
Callsigns held now by people who previously held KO4MFS.
No current licensee on record previously held this callsign.