Confidence: Medium · Source: FCC ULS · As of 2026-09-12
W0COS callsign genealogy
Currently held by FRANK, CARL T
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 W0COS's current licensee, walking backwards.
- Dunagan, Rick DCOgranted 2016-01-05cancelled 2016-07-29
Successor callsigns
Callsigns held now by people who previously held W0COS.
- WILLIAMS, MICHAEL RUTgranted 2024-08-06
All historical holders
Every license row we've seen with the callsign W0COS, oldest first.
- FRANK, CARL T MN1988-05-10 → cancelled 2000-05-11
- WILLIAMS, MICHAEL R UT2007-07-10 → cancelled 2014-07-08
- Dunagan, Rick CO2016-07-29 active