Confidence: Medium · Source: FCC ULS · As of 2026-09-12
N4GSX callsign genealogy
Currently held by Tolosky, Robert G
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 N4GSX's current licensee, walking backwards.
- Tolosky, Robert GFLgranted 2020-05-18cancelled 2020-06-05
Successor callsigns
Callsigns held now by people who previously held N4GSX.
- Markham, Brian PTXgranted 2024-01-06
All historical holders
Every license row we've seen with the callsign N4GSX, oldest first.
- Markham, Brian P MD2009-04-10 → cancelled 2014-04-04
- Tolosky, Robert G FL2020-06-05 active