KC4OS
Active2x2District 4
Competitive callsign — 1 application filed with the FCC.
License HolderRYSNER, ROBERT F
License ClassAdvanced
Min. Class RequiredGeneral
LocationNAPLES, FL
Grant DateDec 16, 2025
Expiration DateFeb 12, 2036
KC4OS is a highly sought-after 2x2 format amateur radio callsign. The license is currently held by RYSNER, ROBERT F in NAPLES, FL. This callsign has attracted significant interest in the amateur radio community, with 1 vanity application filed with the FCC. The most recent was submitted by RYSNER, ROBERT F on Jan 25, 2016. KC4OS has 3 recorded FCC license history events.
CW & Voice Analysis
Morse Code
-.- -.-. ....- --- ...
CW Weight: 34 units(Moderate)
Voice Phonetics
Kilo Charlie Four Oscar Sierra
Readability: 7.5/10(High readability)
License History
- License RenewedDec 16, 2025
- License IssuedFeb 12, 2016
- Vanity Callsign GrantedFeb 12, 2016
Vanity Application Activity
Competing applications filed with the FCC for this callsign.
- RYSNER, ROBERT FFiled Jan 25, 2016Not awardedFCC ↗