Confidence: Medium · Source: FCC ULS · As of 2026-09-12
K4ABJ callsign genealogy
Currently held by Heeder, David M
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 K4ABJ's current licensee, walking backwards.
- Heeder, David MFLgranted 2011-02-03cancelled 2018-10-30
Successor callsigns
Callsigns held now by people who previously held K4ABJ.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign K4ABJ, oldest first.
- BABCOCK, JAMES A NC1998-01-26 → cancelled 2010-01-27
- Heeder, David M FL2018-10-30 active