Confidence: Medium · Source: FCC ULS · As of 2026-09-14
KJ4YSA callsign genealogy
Currently held by Tooyama, Masatoshi
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 KJ4YSA's current licensee, walking backwards.
The current licensee has not held any other callsign on record.
Successor callsigns
Callsigns held now by people who previously held KJ4YSA.
- Tooyama, MasatoshiORgranted 2010-10-08cancelled 2022-10-12