Confidence: Medium · Source: FCC ULS · As of 2026-09-14
KF4YPP callsign genealogy
Currently held by MYTKO, WILLIAM S
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 KF4YPP's current licensee, walking backwards.
- Mytko, William SSCgranted 2020-11-12cancelled 2021-02-17
Successor callsigns
Callsigns held now by people who previously held KF4YPP.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign KF4YPP, oldest first.
- MYTKO, WILLIAM S SC2008-08-27 → cancelled 2020-08-28
- Mytko, William S SC2021-02-17 active