Confidence: Medium · Source: FCC ULS · As of 2026-09-12
KB4AA callsign genealogy
Currently held by Tirrell, Harry D
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 KB4AA's current licensee, walking backwards.
- Tirrell, Harry DTNgranted 2007-09-20cancelled 2014-01-28
Successor callsigns
Callsigns held now by people who previously held KB4AA.
- WALKER, PHILLIP MNDgranted 2005-08-30cancelled 2007-07-17
All historical holders
Every license row we've seen with the callsign KB4AA, oldest first.
- WALKER, PHILLIP M ND2005-03-02 → cancelled 2005-08-30
- Tirrell, Harry D TN2014-01-28 → cancelled 2026-03-07