Confidence: Medium · Source: FCC ULS · As of 2026-09-14
K0JOH callsign genealogy
Currently held by Gratz, John
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 K0JOH's current licensee, walking backwards.
- Gratz, JohnCOgranted 2018-01-22cancelled 2018-02-10
Successor callsigns
Callsigns held now by people who previously held K0JOH.
No current licensee on record previously held this callsign.