Confidence: Medium · Source: FCC ULS · As of 2026-09-12
K4OSJ callsign genealogy
Currently held by Barondes, Mark D
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 K4OSJ's current licensee, walking backwards.
- Barondes, Mark DVAgranted 2017-06-27cancelled 2017-12-29
Successor callsigns
Callsigns held now by people who previously held K4OSJ.
No current licensee on record previously held this callsign.