Confidence: Medium · Source: FCC ULS · As of 2026-09-12
KO0OL callsign genealogy
Currently held by ROBERTS, DOUGLAS E
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 KO0OL's current licensee, walking backwards.
- Lockhart, Heath DARgranted 2022-08-18cancelled 2023-11-14
Successor callsigns
Callsigns held now by people who previously held KO0OL.
- ROBERTS, DOUGLAS EOKgranted 2018-12-15
All historical holders
Every license row we've seen with the callsign KO0OL, oldest first.
- EXPLORER POST 1085 BSA IA2001-04-21 → cancelled 2013-04-23
- ROBERTS, DOUGLAS E OK2015-11-28 → cancelled 2018-12-15
- Lockhart, Heath D AR2023-11-14 active