Confidence: Medium · Source: FCC ULS · As of 2026-09-09
KB4DOC callsign genealogy
Currently held by Zajac, Stephen J
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 KB4DOC's current licensee, walking backwards.
- Zajac, Stephen JSCgranted 2017-06-06cancelled 2024-09-24
Successor callsigns
Callsigns held now by people who previously held KB4DOC.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign KB4DOC, oldest first.
- MANLEY, THOMAS R WV2007-10-19 → cancelled 2020-01-07
- Zajac, Stephen J SC2024-09-24 active