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

N4SDG callsign genealogy

Currently held by GRABOWSKI, HENRY 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 N4SDG's current licensee, walking backwards.

  1. N4CNDcancelled· A
    GRIM III, ORIS AGAgranted 2009-08-25cancelled 2016-02-17
  2. N3CNDcancelled· A
    GRIM III, ORIS AGAgranted 1997-08-01cancelled 1999-11-19

Successor callsigns

Callsigns held now by people who previously held N4SDG.

No current licensee on record previously held this callsign.

All historical holders

Every license row we've seen with the callsign N4SDG, oldest first.

  • GRABOWSKI, HENRY J FL
    1998-02-25 → cancelled 2010-02-26
  • GRIM III, ORIS A GA
    2025-11-27 active
← Back to N4SDG License history →