Confidence: Medium · Source: FCC ULS · As of 2026-09-14
KJ4ZGO callsign genealogy
Currently held by RIDDLE, ISAAC D
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 KJ4ZGO's current licensee, walking backwards.
- RIDDLE, ISAAC DVAgranted 2006-06-29cancelled 2010-11-18
Successor callsigns
Callsigns held now by people who previously held KJ4ZGO.
No current licensee on record previously held this callsign.