Confidence: Medium · Source: FCC ULS · As of 2026-09-12
K9RTB callsign genealogy
Currently held by White, Sean A
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 K9RTB's current licensee, walking backwards.
- White, Sean ACAgranted 2013-10-29cancelled 2014-03-11
Successor callsigns
Callsigns held now by people who previously held K9RTB.
- KLEIN, ROBERT CWIgranted 2016-01-05
All historical holders
Every license row we've seen with the callsign K9RTB, oldest first.
- KLEIN, ROBERT C WI1997-11-10 → cancelled 2006-03-24
- White, Sean A CA2024-07-02 active