Confidence: Medium · Source: FCC ULS · As of 2026-09-12
K4OS callsign genealogy
Currently held by MARIHUGH, WILLIAM
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 K4OS's current licensee, walking backwards.
Successor callsigns
Callsigns held now by people who previously held K4OS.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign K4OS, oldest first.
- MARIHUGH, WILLIAM FL1996-01-18 → cancelled 2005-06-01
- Stokes, Thomas M FL2017-03-28 active