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

N0XXX callsign genealogy

Currently held by CASS, MARK H

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 N0XXX's current licensee, walking backwards.

  1. KF0SLZcancelled· T
    Cass, MarkKSgranted 2024-11-22cancelled 2024-12-10

Successor callsigns

Callsigns held now by people who previously held N0XXX.

  1. KN6JBactive· E
    Breitbach, JimCAgranted 2024-04-05
  2. N0BBCexpired· T
    Gudknecht, JoelMNgranted 2014-01-24cancelled 2026-03-07

All historical holders

Every license row we've seen with the callsign N0XXX, oldest first.

  • CASS, MARK H KS
    1997-01-31 → cancelled 2005-07-28
  • Gudknecht, Joel MN
    2007-03-23 → cancelled 2014-01-24
  • BREITBACH, Jim CA
    2016-07-16 → cancelled 2024-04-05
  • Cass, Mark KS
    2024-12-10 active
← Back to N0XXX License history →