Confidence: Medium · Source: FCC ULS · As of 2026-09-12
KM4NPX callsign genealogy
Currently held by Caldwell, Benjamin M
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 KM4NPX's current licensee, walking backwards.
- Caldwell, Benjamin MTNgranted 2014-09-15cancelled 2015-10-01
Successor callsigns
Callsigns held now by people who previously held KM4NPX.
- Caldwell, Benjamin MGAgranted 2019-12-13