Confidence: Medium · Source: FCC ULS · As of 2026-09-12
WP4SDP callsign genealogy
Currently held by VALLEJO MARRERO, JULIO E
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 WP4SDP'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 WP4SDP.
- VALLEJO MARRERO, JULIO EPRgranted 2022-02-18