Confidence: Medium · Source: FCC ULS · As of 2026-09-12
WP4SFM callsign genealogy
Currently held by CALDERON ACEVEDO, RAMON
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 WP4SFM'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 WP4SFM.
- CALDERON ACEVEDO, RAMONPRgranted 2022-03-25