W4MDU
Available1x3District 4
Competitive callsign — 2 applications filed with the FCC.
License HolderCRONIN, ROBERT M
License ClassTechnician
Min. Class RequiredGeneral
LocationCUPERTINO, CA
Grant DateMar 30, 1995
Expiration DateMar 30, 2005
Cancellation DateMar 31, 2007
Available for ApplicationsMar 31, 2007
W4MDU is a highly sought-after 1x3 format amateur radio callsign. The license is currently held by CRONIN, ROBERT M in CUPERTINO, CA. This callsign has attracted significant interest in the amateur radio community, with 2 vanity applications filed with the FCC. The most recent was submitted by DUNLAP, MICHAEL L on Aug 17, 2026. W4MDU has 1 recorded FCC license history event.
CW & Voice Analysis
Morse Code
.-- ....- -- -.. ..-
CW Weight: 30 units(Light (fast to send))
Voice Phonetics
Whiskey Four Mike Delta Uniform
Readability: 8/10(High readability)
This callsign is available now
Requires General license or higher to apply for this callsign format (1x3).
License History
- License ExpiredMar 31, 2007
Vanity Application Activity
Competing applications filed with the FCC for this callsign.