Confidence: Medium · Source: FCC ULS · As of 2026-09-14
KD9JMB callsign genealogy
Currently held by Babb, Jonathan
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 KD9JMB's current licensee, walking backwards.
- Babb, JonathanILgranted 2026-06-23cancelled 2026-07-21
Successor callsigns
Callsigns held now by people who previously held KD9JMB.
- Ringwood, Steve RWIgranted 2018-01-27
All historical holders
Every license row we've seen with the callsign KD9JMB, oldest first.
- Ringwood, Steve R WI2017-10-19 → cancelled 2018-01-27
- Babb, Jonathan IL2026-07-21 active