Confidence: Medium · Source: FCC ULS · As of 2026-09-14
K9DOT callsign genealogy
Currently held by Sobtzak, Samuel R
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 K9DOT's current licensee, walking backwards.
- Sobtzak, Samuel RWIgranted 2025-01-11cancelled 2025-01-31
Successor callsigns
Callsigns held now by people who previously held K9DOT.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign K9DOT, oldest first.
- MARQUARD, RUTH M IL2008-11-14 → cancelled 2021-02-13
- Sobtzak, Samuel R WI2025-01-31 active