Confidence: Medium · Source: FCC ULS · As of 2026-09-12
W4JDK callsign genealogy
Currently held by KNISLEY, JOHN D
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 W4JDK's current licensee, walking backwards.
- KNISLEY, JOHN DFLgranted 2006-09-06cancelled 2006-09-26
Successor callsigns
Callsigns held now by people who previously held W4JDK.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign W4JDK, oldest first.
- BUYCK JR, DAVID D SC1994-05-31 → cancelled 2006-06-01
- KNISLEY, JOHN D FL2026-07-17 active