Confidence: Medium · Source: FCC ULS · As of 2026-09-12
W9OTC callsign genealogy
Currently held by KOLBERG, MATTHEW S
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 W9OTC's current licensee, walking backwards.
- KOLBERG, MATTHEW SILgranted 2014-11-14cancelled 2021-04-06
Successor callsigns
Callsigns held now by people who previously held W9OTC.
No current licensee on record previously held this callsign.