Confidence: Medium · Source: FCC ULS · As of 2026-09-14
W1SFO callsign genealogy
Currently held by Mortenson, Richard M
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 W1SFO's current licensee, walking backwards.
- Mortenson, Richard MCAgranted 2004-02-23cancelled 2004-03-12
Successor callsigns
Callsigns held now by people who previously held W1SFO.
- Mortenson, Richard MCAgranted 2016-04-05