Confidence: Medium · Source: FCC ULS · As of 2026-09-14
N4JKU callsign genealogy
Currently held by FRANGIADAKIS, MARTHA H
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 N4JKU's current licensee, walking backwards.
Successor callsigns
Callsigns held now by people who previously held N4JKU.
- SHELDON SR, JOSEPH MNCgranted 2022-02-11
All historical holders
Every license row we've seen with the callsign N4JKU, oldest first.
- FRANGIADAKIS, MARTHA H FL1994-06-22 → cancelled 2006-06-23
- SHELDON SR, JOSEPH M NC2020-06-16 → cancelled 2022-02-11