Confidence: Medium · Source: FCC ULS · As of 2026-09-14
N4ZBK callsign genealogy
Currently held by SCHWARTZMAN, MITCHELL S
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 N4ZBK's current licensee, walking backwards.
- SCHWARTZMAN, MITCHELL SFLgranted 2021-03-23cancelled 2021-04-13
Successor callsigns
Callsigns held now by people who previously held N4ZBK.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign N4ZBK, oldest first.
- DUCHARME, JOHN O FL1990-08-21 → cancelled 2002-08-22
- SCHWARTZMAN, MITCHELL S FL2021-04-13 active