Confidence: Medium · Source: FCC ULS · As of 2026-09-12
AC9MK callsign genealogy
Currently held by Ulrich, Thomas M
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 AC9MK's current licensee, walking backwards.
Successor callsigns
Callsigns held now by people who previously held AC9MK.
No current licensee on record previously held this callsign.