Confidence: Medium · Source: FCC ULS · As of 2026-09-12
K6DRF callsign genealogy
Currently held by Filter, Douglas R
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 K6DRF's current licensee, walking backwards.
- Filter, Douglas RCAgranted 2018-04-06cancelled 2020-03-21
Successor callsigns
Callsigns held now by people who previously held K6DRF.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign K6DRF, oldest first.
- COSSAREK, HARRY D OR1999-05-03 → cancelled 2011-05-04
- Filter, Douglas R CA2020-03-21 active