Confidence: Medium · Source: FCC ULS · As of 2026-09-12
AI4JS callsign genealogy
Currently held by Madderra, Bob L
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 AI4JS's current licensee, walking backwards.
- Madderra, Bob LGAgranted 2004-12-10cancelled 2005-03-23
Successor callsigns
Callsigns held now by people who previously held AI4JS.
- Madderra, Robert LGAgranted 2025-04-11