Confidence: Medium · Source: FCC ULS · As of 2026-09-12
KP4FOC callsign genealogy
Currently held by First Class CW Operators Club Of Puerto Rico
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 KP4FOC's current licensee, walking backwards.
- WP4SXBcancelledFirst Class CW Operators Club Of Puerto RicoPRgranted 2023-07-11cancelled 2023-08-01
Successor callsigns
Callsigns held now by people who previously held KP4FOC.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign KP4FOC, oldest first.
- GUZMAN SR, GUSTAVO PR1990-04-10 → cancelled 2002-04-11
- First Class CW Operators Club Of Puerto Rico PR2023-08-01 active