Confidence: Medium · Source: FCC ULS · As of 2026-09-12
KP4L callsign genealogy
Currently held by RUBIO, SERGIO R
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 KP4L's current licensee, walking backwards.
Successor callsigns
Callsigns held now by people who previously held KP4L.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign KP4L, oldest first.
- RUBIO, SERGIO R PR2008-11-20 → cancelled 2021-01-19
- NEGRON, GERARDO PR2021-02-06 active