Confidence: Medium · Source: FCC ULS · As of 2026-09-12
W4SDR callsign genealogy
Currently held by SEMI DEDICATED RADIO CONTEST CLUB
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 W4SDR's current licensee, walking backwards.
- McElroy, Thomas HGAgranted 2007-06-19cancelled 2010-12-28
Successor callsigns
Callsigns held now by people who previously held W4SDR.
- K4DTXactiveFABER ALUMNI RADIO COMMUNICATIONS EXPERIMENTERSGAgranted 2018-09-18
All historical holders
Every license row we've seen with the callsign W4SDR, oldest first.
- SEMI DEDICATED RADIO CONTEST CLUB GA1998-11-18 → cancelled 2008-11-21
- McElroy, Thomas H GA2020-10-22 active