Confidence: Medium · Source: FCC ULS · As of 2026-09-14
KD9WTF callsign genealogy
Currently held by Szewczyk, John W
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 KD9WTF's current licensee, walking backwards.
- Lange, Stephen LILgranted 2018-01-30cancelled 2018-02-27
Successor callsigns
Callsigns held now by people who previously held KD9WTF.
- Szewczyk, John WILgranted 2015-10-20
All historical holders
Every license row we've seen with the callsign KD9WTF, oldest first.
- Szewczyk, John W IL2014-05-06 → cancelled 2015-10-20
- Lange, Stephen L IL2018-02-27 active