Confidence: Medium · Source: FCC ULS · As of 2026-09-12
K5GSC callsign genealogy
Currently held by WILLIAMS, MARK S
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 K5GSC's current licensee, walking backwards.
- HOLMES, ROBERT JOKgranted 2013-05-21cancelled 2017-06-13
Successor callsigns
Callsigns held now by people who previously held K5GSC.
- WILLIAMS, MARK STXgranted 2001-06-05cancelled 2002-04-25
All historical holders
Every license row we've seen with the callsign K5GSC, oldest first.
- WILLIAMS, MARK S TX1999-05-26 → cancelled 2001-06-05
- HOLMES, ROBERT J OK2017-06-13 active