ComTekk SELCAL 4.0

ComTekk SELCAL generates Aviation SELCAL or selective-calling tones using your computer's sound card.
Used by airlines and aeronautical radio operators to "page" specific aircraft during flight via HF or VHF radio. Quick installation and setup, simple to use.
SELCAL is an international signaling protocol which allows airline radio operators to contact specific aircraft over HF of VHF radio while in flight. The SELCAL decoder on board each aircraft is assigned a unique 4-letter code. This allows the receiver audio to be muted until that code is received, alerting the crew there is a radio call for them. This way, they do not have to be distracted by radio traffic intended for other planes.