Confidence: Medium · Source: FCC ULS · As of 2026-09-12
WB4MAD callsign genealogy
Currently held by NIX, DONALD B
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 WB4MAD's current licensee, walking backwards.
- Derrico, MarkMIgranted 2021-03-15cancelled 2021-04-02
Successor callsigns
Callsigns held now by people who previously held WB4MAD.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign WB4MAD, oldest first.
- NIX, DONALD B SC2002-04-12 → cancelled 2014-04-15
- Derrico, Mark MI2021-04-02 active