operating signal for "request to communicate"
Connections
Morse code
Entity
call sign
Entity
Japan
Country
Australia
Country
United Kingdom
Country
French
Entity
radio
Entity
International Standard Book Number
Entity
Titanic
Concept
frequency
Entity
International Telecommunication Union
Entity
OCLC, Inc.
Entity
Universal Postal Union
Entity
amateur radio
Entity
frequency modulation
Entity
wireless communication
Entity
Q214266
Entity
ultra high frequency
Entity
very high frequency
Entity
shortwave radio
Entity