Confidence: Medium · Source: FCC ULS · As of 2026-09-14
KF4OZO callsign genealogy
Currently held by DERRICK, WILLIAM H
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 KF4OZO's current licensee, walking backwards.
- Derrick, Ronald WTNgranted 2010-06-04cancelled 2010-07-07
Successor callsigns
Callsigns held now by people who previously held KF4OZO.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign KF4OZO, oldest first.
- DERRICK, WILLIAM H TN2007-01-18 → cancelled 2008-08-23
- Derrick, Ronald W TN2020-06-09 active