Confidence: Medium · Source: FCC ULS · As of 2026-09-12
K0DYY callsign genealogy
Currently held by Swallow, John A
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 K0DYY's current licensee, walking backwards.
- Swallow, John ACAgranted 2010-02-17cancelled 2011-03-01
Successor callsigns
Callsigns held now by people who previously held K0DYY.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign K0DYY, oldest first.
- MAYO, HORACE M MN1998-09-10 → cancelled 2010-09-11
- Swallow, John A CA2020-12-02 active