Confidence: Medium · Source: FCC ULS · As of 2026-09-14
K4MZR callsign genealogy
Currently held by OLIVENBAUM, JAMES E
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 K4MZR's current licensee, walking backwards.
- Shelton, Gregg AVAgranted 2015-09-01cancelled 2015-09-29
Successor callsigns
Callsigns held now by people who previously held K4MZR.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign K4MZR, oldest first.
- OLIVENBAUM, JAMES E TX1997-09-26 → cancelled 2009-09-29
- Shelton, Gregg A VA2025-08-13 active