Confidence: Medium · Source: FCC ULS · As of 2026-09-12
WP4MHZ callsign genealogy
Currently held by CASTILLO RODRIGUEZ, CARLOS
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 WP4MHZ's current licensee, walking backwards.
- CASTILLO RODRIGUEZ, CARLOSPRgranted 2018-01-08cancelled 2018-01-26
Successor callsigns
Callsigns held now by people who previously held WP4MHZ.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign WP4MHZ, oldest first.
- CASTILLO RODRIGUEZ, CARLOS PR1993-08-10 → cancelled 2005-08-11
- CASTILLO RODRIGUEZ, CARLOS PR2018-01-26 active