Confidence: Medium · Source: FCC ULS · As of 2026-09-14
W9YIY callsign genealogy
Currently held by GUENNEWIG, WILLIAM F
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 W9YIY's current licensee, walking backwards.
- TIEMANN, CHARLESILgranted 2023-05-25cancelled 2024-06-04
Successor callsigns
Callsigns held now by people who previously held W9YIY.
- TIEMANN, CHARLESILgranted 2024-06-28
All historical holders
Every license row we've seen with the callsign W9YIY, oldest first.
- GUENNEWIG, WILLIAM F IL1994-11-21 → cancelled 2006-11-22
- TIEMANN, CHARLES IL2024-06-04 → cancelled 2024-06-28