Confidence: Medium · Source: FCC ULS · As of 2026-09-12
K6SDZ callsign genealogy
Currently held by Santos, Ryan M
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 K6SDZ's current licensee, walking backwards.
- Santos, Ryan MCAgranted 2024-09-10cancelled 2025-06-03
Successor callsigns
Callsigns held now by people who previously held K6SDZ.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign K6SDZ, oldest first.
- WATSON, THOMAS B CA1988-11-15 → cancelled 2000-11-16
- Santos, Ryan M CA2025-06-03 active