Confidence: Medium · Source: FCC ULS · As of 2026-09-14
W9SU callsign genealogy
Currently held by KOSS, MICHAEL R
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 W9SU's current licensee, walking backwards.
Successor callsigns
Callsigns held now by people who previously held W9SU.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign W9SU, oldest first.
- KOSS, MICHAEL R IN2006-01-26 → cancelled 2011-03-28
- Indy United ARC IN2022-11-26 active