Confidence: Medium · Source: FCC ULS · As of 2026-09-12
K4FZH callsign genealogy
Currently held by Holmstock, Fred Z
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 K4FZH's current licensee, walking backwards.
- Holmstock, Fred ZFLgranted 2023-03-13cancelled 2023-05-06
Successor callsigns
Callsigns held now by people who previously held K4FZH.
- CHARLETON, KENNETHAZgranted 2018-06-19
All historical holders
Every license row we've seen with the callsign K4FZH, oldest first.
- CHARLETON, KENNETH AZ2010-11-05 → cancelled 2018-06-19
- Holmstock, Fred Z FL2023-05-06 active