Confidence: Medium · Source: FCC ULS · As of 2026-09-12
K4JTZ callsign genealogy
Currently held by Horn, Mark J
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 K4JTZ's current licensee, walking backwards.
- Horn, Mark JFLgranted 2023-07-07cancelled 2025-12-09
Successor callsigns
Callsigns held now by people who previously held K4JTZ.
No current licensee on record previously held this callsign.