Confidence: Medium · Source: FCC ULS · As of 2026-09-14
W7JSK callsign genealogy
Currently held by Karczewski, John S
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 W7JSK's current licensee, walking backwards.
- KAWANO, SEIJIINgranted 2017-08-25cancelled 2025-01-28
Successor callsigns
Callsigns held now by people who previously held W7JSK.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign W7JSK, oldest first.
- Karczewski, John S NV2012-01-14 → cancelled 2024-01-17
- KAWANO, SEIJI IN2025-01-28 active