Confidence: Medium · Source: FCC ULS · As of 2026-09-14
KZ9T callsign genealogy
Currently held by Treffert, Thomas
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 KZ9T's current licensee, walking backwards.
- Treffert, ThomasCAgranted 2019-11-22cancelled 2020-01-24
Successor callsigns
Callsigns held now by people who previously held KZ9T.
- Mende, Darren PILgranted 2017-12-22
All historical holders
Every license row we've seen with the callsign KZ9T, oldest first.
- SAHR, DAVID R IL2003-09-23 → cancelled 2015-11-24
- Mende, Darren P IL2015-12-12 → cancelled 2017-12-22
- Treffert, Thomas TX2020-01-24 active