KR4ISO
Cancelled2x3District 4
No competing applications on record.
License HolderKnudsen, Jonathan A
License ClassTechnician
Min. Class RequiredTechnician
LocationClarksville, TN
Grant DateJan 6, 2026
Cancellation DateFeb 7, 2026
Available for ApplicationsFeb 8, 2028
KR4ISO is a 2x3 format amateur radio callsign. It is currently registered to Knudsen, Jonathan A in Clarksville, TN. There are currently no competing vanity applications or pending FCC filings on record for this callsign. Add it to your watchlist to receive an immediate alert if another operator files a vanity application.
CW & Voice Analysis
Morse Code
-.- .-. ....- .. ... ---
CW Weight: 33 units(Moderate)
Voice Phonetics
Kilo Romeo Four India Sierra Oscar
Readability: 6/10(Good readability)
Available Feb 8, 2028 (522 days remaining)
Requires Technician license or higher to apply for this callsign format (2x3).
License History
- License CanceledFeb 7, 2026
- System-Generated GrantJan 6, 2026
- License IssuedJan 6, 2026
Vanity Application Activity
Competing applications filed with the FCC for this callsign.
No competing applications on record. Verify on the FCC ULS application search before filing.