uls-tracker
Sign in
Confidence: Medium · Source: FCC ULS · As of 2026-09-12

N9FO callsign genealogy

Currently held by OSINSKI, 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 N9FO's current licensee, walking backwards.

  1. WD8NZPcancelled· E
    OSINSKI, MARK AWIgranted 2016-06-07cancelled 2024-06-25

Successor callsigns

Callsigns held now by people who previously held N9FO.

No current licensee on record previously held this callsign.

All historical holders

Every license row we've seen with the callsign N9FO, oldest first.

  • Creek, James L IL
    2012-03-14 → cancelled 2024-06-05
  • OSINSKI, MARK A WI
    2024-06-25 active