Confidence: Medium · Source: FCC ULS · As of 2026-09-12
K3SDL callsign genealogy
Currently held by Colbert, R John
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 K3SDL's current licensee, walking backwards.
- Simpson, Daniel LMDgranted 2020-06-22cancelled 2021-07-09
Successor callsigns
Callsigns held now by people who previously held K3SDL.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign K3SDL, oldest first.
- Colbert, R John TX2008-12-02 → cancelled 2021-01-27
- Simpson, Daniel L MD2021-07-09 active