Confidence: Medium · Source: FCC ULS · As of 2026-09-12
W3MSR callsign genealogy
Currently held by Rosenthal, Mark 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 W3MSR's current licensee, walking backwards.
- Rosenthal, Mark SMDgranted 2012-04-25cancelled 2012-05-15
Successor callsigns
Callsigns held now by people who previously held W3MSR.
- Rosenthal, Mark SMEgranted 2022-07-15