Confidence: Medium · Source: FCC ULS · As of 2026-09-12
AA9U callsign genealogy
Currently held by ZIMMERMAN, JOHN L
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 AA9U's current licensee, walking backwards.
- Williams, James HILgranted 2001-02-05cancelled 2001-05-08
Successor callsigns
Callsigns held now by people who previously held AA9U.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign AA9U, oldest first.
- ZIMMERMAN, JOHN L FL1989-02-14 → cancelled 2001-02-15
- Williams, James H IL2021-03-03 active