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

WD4MRK callsign genealogy

Currently held by SHERER, MARK 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 WD4MRK's current licensee, walking backwards.

  1. W5MRKactive· E
    JOOSTEN, MARK MNMgranted 2024-05-11
  2. KD5CRDcancelled· E
    JOOSTEN, MARK MNMgranted 1997-11-17cancelled 2004-04-13

Successor callsigns

Callsigns held now by people who previously held WD4MRK.

No current licensee on record previously held this callsign.

← Back to WD4MRK License history →