Confidence: Medium · Source: FCC ULS · As of 2026-09-14
KO4SM callsign genealogy
Currently held by SIMPSON, EDGAR W
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 KO4SM's current licensee, walking backwards.
- Scarmoutzos, LouisSCgranted 2021-08-10cancelled 2021-10-15
Successor callsigns
Callsigns held now by people who previously held KO4SM.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign KO4SM, oldest first.
- SIMPSON, EDGAR W NY2001-11-28 → cancelled 2014-02-26
- Scarmoutzos, Louis SC2021-10-15 active