About ComTekk SELCAL:
Software description
ComTekk SELCAL makes use of the computer sound card to generate Aviation SELCAL or selective-calling tones. This 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 all the radio traffic intended for other planes.
SELCAL (ARINC-714 standard or ICAO Annex 10) is a dual-tone (2x2) format like DTMF, but uses 16 different tone frequencies. Each digit or letter in the code sequence refers to an audio tone frequency. The first two digits comprise the first tone pair, and the last two digits determine the second pair of tone frequencies. Version 4.1 and later meets the Mark 4 specification with 32 tones.
CTSelcal includes a convenient auto-calibration system which compensates for errors in the sound card's timebase, ensuring accurate tones are produced. This is critical, as the tone frequencies must be very precise to be decoded by the aircraft's electronic decoder.
ComTekk SELCAL is one of the many software DSP tools for radio communications signaling offered by ComTekk Software.
SELCAL Resources
To request a SELCAL code for your aircraft, use the ASRI request form here: http://www.asri.aero/cf/selcal_request.cfm
SelcalWeb maintains an online code database, searchable by code: http://www.selcalweb.co.uk/
A pilot's tutorial of oceanic radio procedures, including HF SELCAL: http://zak.vatusa.net/tutor/oceanic_procedures_tutorial.htm
Notice: This software has not been certified by the FAA.
1. Credits
Author:
Brian R. Williams, NB5R
ComTekk Engineering, LLC
www.comtekk.com
ComTekk SELCAL was designed for ARTCC and aviation dispatchers to "page" certain aircraft, especially on overseas flights. Using a MS Windows-based PC and ComTekk Radio Interface, CTSelcal is a low-cost alternative to expensive hardware-based encoders, offering excellent performance and value. See ComTekk Web Site for recommended devices and radio interfaces.
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2. License
To view the License Agreement, click:
Start->Programs->ComTekk->CTSelcal->License