uls-tracker
Sign in
Confidence: Medium · Source: FCC ULS · As of 2026-09-12

K6JSX callsign genealogy

Currently held by MARK, RUSSEL L

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 K6JSX's current licensee, walking backwards.

  1. KE8KTZcancelled· G
    Sawyer, JonathanMIgranted 2018-10-23cancelled 2018-11-10

Successor callsigns

Callsigns held now by people who previously held K6JSX.

No current licensee on record previously held this callsign.

All historical holders

Every license row we've seen with the callsign K6JSX, oldest first.

  • MARK, RUSSEL L CA
    1999-02-11 → cancelled 2011-02-12
  • Sawyer, Jonathan MI
    2018-11-10 active