Confidence: Medium · Source: FCC ULS · As of 2026-09-14
KD4HAX callsign genealogy
Currently held by Klein, Joseph 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 KD4HAX's current licensee, walking backwards.
- Klein, Joseph SVAgranted 2017-09-26cancelled 2017-11-18
Successor callsigns
Callsigns held now by people who previously held KD4HAX.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign KD4HAX, oldest first.
- FRANKLIN JR, HENRY F TX2003-04-26 → cancelled 2015-04-28
- Klein, Joseph S VA2017-11-18 active