Confidence: Medium · Source: FCC ULS · As of 2026-09-12
K4HMF callsign genealogy
Currently held by ARMSTEAD, GEOFFREY
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 K4HMF's current licensee, walking backwards.
- ARMSTEAD, GEOFFREYTNgranted 2011-08-25cancelled 2018-04-03
Successor callsigns
Callsigns held now by people who previously held K4HMF.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign K4HMF, oldest first.
- CASTRY, JOHN A FL1997-02-20 → cancelled 2009-02-21
- ARMSTEAD, GEOFFREY TN2018-04-03 active