uls-tracker
Sign in
Confidence: Medium · Source: FCC ULS · As of 2026-09-14

KJ4WB callsign genealogy

Currently held by ZAWACKI, STEPHEN J

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 KJ4WB's current licensee, walking backwards.

  1. KB1AXactive· E
    Sypek, Michael SRIgranted 2023-09-07
  2. KB1YJBcancelled· E
    Sypek, Michael SRIgranted 2012-06-25cancelled 2013-11-09

Successor callsigns

Callsigns held now by people who previously held KJ4WB.

  1. W4SJZcancelled· A
    ZAWACKI, STEPHEN JFLgranted 2018-11-24cancelled 2020-06-20
← Back to KJ4WB License history →