Confidence: Medium · Source: FCC ULS · As of 2026-09-14
KZ4MKJ callsign genealogy
Currently held by Jacobs, Mark 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 KZ4MKJ's current licensee, walking backwards.
- Jacobs, Mark WFLgranted 2021-05-11cancelled 2021-06-02
Successor callsigns
Callsigns held now by people who previously held KZ4MKJ.
No current licensee on record previously held this callsign.