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

KG4JAM callsign genealogy

Currently held by McMahan, John 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 KG4JAM's current licensee, walking backwards.

  1. KQ4OHCcancelled· T
    McMahan, John ANCgranted 2024-02-01cancelled 2026-01-06

Successor callsigns

Callsigns held now by people who previously held KG4JAM.

No current licensee on record previously held this callsign.

All historical holders

Every license row we've seen with the callsign KG4JAM, oldest first.

  • CLEVELAND, MARK W IL
    2010-06-04 → cancelled 2022-08-16
  • McMahan, John A NC
    2026-01-06 active