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Confidence: Medium · Source: FCC ULS · As of 2026-09-12

N4RRM callsign genealogy

Currently held by MUDERSBACH, RONALD A

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 N4RRM's current licensee, walking backwards.

  1. KO4SUTcancelled· T
    Heid, RyanSCgranted 2021-08-23cancelled 2021-10-13

Successor callsigns

Callsigns held now by people who previously held N4RRM.

  1. AB9TMcancelled· E
    MUDERSBACH, RONALD AWIgranted 2008-12-18cancelled 2009-06-13

All historical holders

Every license row we've seen with the callsign N4RRM, oldest first.

  • MUDERSBACH, RONALD A WI
    2008-12-18 → cancelled 2009-04-07
  • Heid, Ryan C SC
    2021-10-13 active
← Back to N4RRM License history →