Confidence: Medium · Source: FCC ULS · As of 2026-09-11
KB4MTZ callsign genealogy
Currently held by MARTINEZ, JULIO D
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 KB4MTZ's current licensee, walking backwards.
- MARTINEZ, JULIO DCAgranted 2013-01-22cancelled 2015-10-09
Successor callsigns
Callsigns held now by people who previously held KB4MTZ.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign KB4MTZ, oldest first.
- LLOYD JR, WILMER W VA1997-02-10 → cancelled 2009-02-11
- MARTINEZ, JULIO D CA2015-10-09 active