Confidence: Medium · Source: FCC ULS · As of 2026-09-12
KN4UPL callsign genealogy
Currently held by Muller, Karl F
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 KN4UPL's current licensee, walking backwards.
The current licensee has not held any other callsign on record.
Successor callsigns
Callsigns held now by people who previously held KN4UPL.
- Muller, Karl FVAgranted 2019-06-04