Confidence: Medium · Source: FCC ULS · As of 2026-09-14
W3TBX callsign genealogy
Currently held by GRUMBINE, WILLIAM H
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 W3TBX's current licensee, walking backwards.
- Miller, Kathy MPAgranted 2008-10-09cancelled 2008-10-28
Successor callsigns
Callsigns held now by people who previously held W3TBX.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign W3TBX, oldest first.
- GRUMBINE, WILLIAM H PA1995-10-12 → cancelled 1998-11-09
- Miller, Kathy M PA2018-07-31 active