Confidence: Medium · Source: FCC ULS · As of 2026-09-14
KK6ZO callsign genealogy
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 KK6ZO's current licensee, walking backwards.
- Ohashi, ZentaroCAgranted 2025-11-26cancelled 2026-03-24
Successor callsigns
Callsigns held now by people who previously held KK6ZO.
- COSTELLO, GUILLERMO ACAgranted 2017-06-06
All historical holders
Every license row we've seen with the callsign KK6ZO, oldest first.
- Ohashi, Zentaro CA2026-03-24 active
- —— → cancelled 1997-08-21