Confidence: Medium · Source: FCC ULS · As of 2026-09-12
KC9TCO callsign genealogy
Currently held by Eisenmann, Jonathan 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 KC9TCO's current licensee, walking backwards.
- Enger, Michael AWIgranted 2022-07-22cancelled 2026-03-21
Successor callsigns
Callsigns held now by people who previously held KC9TCO.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign KC9TCO, oldest first.
- Eisenmann, Jonathan A IL2010-09-23 → cancelled 2022-09-24
- Enger, Michael A IA2026-03-21 active