Confidence: Medium · Source: FCC ULS · As of 2026-09-12
ND4K callsign genealogy
Currently held by JEFFERIES, THEODORE 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 ND4K's current licensee, walking backwards.
- PROBST, DAVID CGAgranted 2011-07-23cancelled 2016-10-21
Successor callsigns
Callsigns held now by people who previously held ND4K.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign ND4K, oldest first.
- JEFFERIES, THEODORE R FL2013-03-08 → cancelled 2014-10-02
- PROBST, DAVID C GA2026-07-25 active