Confidence: Medium · Source: FCC ULS · As of 2026-09-12
KF4SS callsign genealogy
Currently held by Madderra, Robert 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 KF4SS's current licensee, walking backwards.
Successor callsigns
Callsigns held now by people who previously held KF4SS.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign KF4SS, oldest first.
- AMOS, ARTHUR E AL1988-03-29 → cancelled 2000-03-30
- Madderra, Robert L GA2025-04-11 active