Confidence: Medium · Source: FCC ULS · As of 2026-09-12
AC4DA callsign genealogy
Currently held by BIRGENHEIER, LEO G
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 AC4DA's current licensee, walking backwards.
- AB4ZYno FCC ULS record on file
Successor callsigns
Callsigns held now by people who previously held AC4DA.
No current licensee on record previously held this callsign.