Confidence: Medium · Source: FCC ULS · As of 2026-09-12
KY4IO callsign genealogy
Currently held by PIZER, MARK 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 KY4IO's current licensee, walking backwards.
- PIZER, MARK HNCgranted 2019-06-24cancelled 2021-06-28
Successor callsigns
Callsigns held now by people who previously held KY4IO.
No current licensee on record previously held this callsign.