Confidence: Medium · Source: FCC ULS · As of 2026-09-14
KR4KKK callsign genealogy
Currently held by Grinwis, John E
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 KR4KKK's current licensee, walking backwards.
- Grinwis, John EFLgranted 2025-12-04cancelled 2026-08-21
Successor callsigns
Callsigns held now by people who previously held KR4KKK.
No current licensee on record previously held this callsign.