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

K4SDM callsign genealogy

Currently held by SPRAGUE, DAVID M

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 K4SDM's current licensee, walking backwards.

  1. KN4DYEcancelled· G
    MATHEWS JR, STEPHEN DGAgranted 2017-06-14cancelled 2020-06-13

Successor callsigns

Callsigns held now by people who previously held K4SDM.

  1. NC4DCactive· E
    SPRAGUE, DAVID MFLgranted 2020-12-04

All historical holders

Every license row we've seen with the callsign K4SDM, oldest first.

  • SPRAGUE, DAVID M NC
    2011-01-04 → cancelled 2011-03-01
  • Mathews Jr, Stephen D GA
    2020-06-13 active
← Back to K4SDM License history →