Confidence: Medium · Source: FCC ULS · As of 2026-09-12
K6SFX callsign genealogy
Currently held by O'Brien IV, Edward 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 K6SFX's current licensee, walking backwards.
- O'Brien IV, Edward TCAgranted 2016-07-13cancelled 2016-09-07
Successor callsigns
Callsigns held now by people who previously held K6SFX.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign K6SFX, oldest first.
- MATSON, LESLIE B CA1996-04-11 → cancelled 2008-04-12
- O'Brien IV, Edward T CA2016-09-07 active