Confidence: Medium · Source: FCC ULS · As of 2026-09-14
AJ4DU callsign genealogy
Currently held by Retzloff, Robin L
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 AJ4DU's current licensee, walking backwards.
- Retzloff, Robin LFLgranted 2007-07-02cancelled 2007-12-07
Successor callsigns
Callsigns held now by people who previously held AJ4DU.
- Retzloff, Robin LMIgranted 2017-12-27