Confidence: Medium · Source: FCC ULS · As of 2026-09-12
W4ZL callsign genealogy
Currently held by MULLER, FREDERICK J
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 W4ZL's current licensee, walking backwards.
Successor callsigns
Callsigns held now by people who previously held W4ZL.
No current licensee on record previously held this callsign.