Confidence: Medium · Source: FCC ULS · As of 2026-09-12
W4UDJ callsign genealogy
Currently held by BROWN, MARTHA A
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 W4UDJ's current licensee, walking backwards.
- BROWN, MARTHA ACOgranted 2008-05-08cancelled 2018-01-13
Successor callsigns
Callsigns held now by people who previously held W4UDJ.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign W4UDJ, oldest first.
- HEERTEN, LOUIS F AL1997-06-17 → cancelled 2001-06-24
- BROWN, MARTHA A CO2018-01-13 active