Confidence: Medium · Source: FCC ULS · As of 2026-09-14
K9JZM callsign genealogy
Currently held by COLLATZ, ARTHUR 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 K9JZM's current licensee, walking backwards.
- Collatz, Arthur SWIgranted 2007-10-01cancelled 2008-01-15
Successor callsigns
Callsigns held now by people who previously held K9JZM.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign K9JZM, oldest first.
- COLLATZ, ARTHUR G IL2001-11-07 → cancelled 2006-09-20
- Collatz, Arthur S WI2017-11-25 active