Confidence: Medium · Source: FCC ULS · As of 2026-09-12
K8COS callsign genealogy
Currently held by Costantino, John J
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 K8COS's current licensee, walking backwards.
- Costantino, John JOHgranted 2024-06-27cancelled 2024-07-23
Successor callsigns
Callsigns held now by people who previously held K8COS.
No current licensee on record previously held this callsign.