Confidence: Medium · Source: FCC ULS · As of 2026-09-12
W5DD callsign genealogy
Currently held by Nielsen, William B
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 W5DD's current licensee, walking backwards.
- Mihalko, Thomas JTXgranted 2020-02-06cancelled 2020-04-21
Successor callsigns
Callsigns held now by people who previously held W5DD.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign W5DD, oldest first.
- Nielsen, William B NM2010-01-15 → cancelled 2018-04-02
- Mihalko, Thomas J TX2020-04-21 active