Confidence: Medium · Source: FCC ULS · As of 2026-09-12
N4OZ callsign genealogy
Currently held by KLAUS, HOWARD V
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 N4OZ's current licensee, walking backwards.
- Grebert, Michael JTNgranted 2011-01-31cancelled 2011-07-15
Successor callsigns
Callsigns held now by people who previously held N4OZ.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign N4OZ, oldest first.
- KLAUS, HOWARD V CA1999-06-24 → cancelled 2011-06-25
- Grebert, Michael J TN2021-11-27 active