Confidence: Medium · Source: FCC ULS · As of 2026-09-12
KD9CSJ callsign genealogy
Currently held by Boisen, Robert
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 KD9CSJ's current licensee, walking backwards.
- Boisen, RobertWIgranted 2014-11-18cancelled 2014-12-16
Successor callsigns
Callsigns held now by people who previously held KD9CSJ.
- Boisen, RobertWIgranted 2014-11-18cancelled 2017-04-11