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KC1SOW

Active2x3District 1

Competitive callsign — 1 application filed with the FCC.

License HolderKlemm, Mark S

License ClassGeneral

Min. Class RequiredTechnician

LocationDanville, NH

Grant DateSep 20, 2025

Expiration DateSep 20, 2035

KC1SOW is a highly sought-after 2x3 format amateur radio callsign. The license is currently held by Klemm, Mark S in Danville, NH. 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 Klemm, Mark S on Sep 2, 2025. KC1SOW has 6 recorded FCC license history events.

CW & Voice Analysis

Morse Code

-.- -.-. .---- ... --- .--

CW Weight: 47 units(Heavy (slower to send))

Voice Phonetics

Kilo Charlie One Sierra Oscar Whiskey

Readability: 7/10(Good readability)

License History

License IssuedSep 20, 2025
Vanity Callsign GrantedSep 20, 2025
License CanceledMay 30, 2025
License ModifiedJun 27, 2023
System-Generated GrantMar 3, 2023
License IssuedMar 3, 2023

Vanity Application Activity

Competing applications filed with the FCC for this callsign.

Klemm, Mark SFiled Sep 2, 2025
Not awardedFCC ↗

Search external databases

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FCC data as of Sep 3, 2026

KC1SOW FCC Vanity Status: 1 Competing Application & History