29BARRETT 4050 HF SDR TRANSCEIVER - OPERATING AND INSTALLATION MANUALSelective Call - SelcallSelcall (selective calling) is a digital signalling system based on the standardCCIR-493 for use on HF networks. It is a type of squelch protocol used inradio communications systems, in which transmissions include a brief burst ofsequential audio tones. Receivers that are set to respond to the transmittedtone sequence will open their squelch, while others will remain muted.Selcall Self IDsEach station in an HF network can be assigned up to 14 different Self IDs ofZKLFKWKHUHFDQEHDPL[WXUHRIIRXURUVL[GLJLW,'V LGHQWLÀFDWLRQ $VWDWLRQcan be called using any of these Self IDs.Selcall DecodeThe Transceiver has the ability to decode both OEM and International Selcallson any channel programmed as a Selcall channel. However, the call must beaddressed to the relevant ID (OEM or International).Calls for each format type will only be decoded if there is at least one Self ID ofthat format programmed into the Transceiver Self ID group.Selcall Transmit6HOFDOOIRUPDWVLQWUDQVPLWDUHFKDQQHOVSHFLÀF)RUH[DPSOHRQO\FDOOW\SHVprogrammed for the channel are permitted. This means International and CCIRformat calls can only be sent on channels that are programmed as Internationalor CCIR Selcall channels. OEM calls can only be sent on channels that are pro-grammed as OEM Selcall channels.Selective Call - TelcallTelcall uses this digital Selective Call system to send a telephone number from astation on an HF network to a base station equipped with a telephone inter-connect unit to initiate phone calls onto the PSTN.1RWH )RU6HOFDOODQG7HOFDOOIXQFWLRQVWRRSHUDWHWKH7UDQVFHLYHUPXVWEHÀWWHGZLWKthe Selcall or Telcall option and the channels enabled for Selcall operation.If Automatic Link establishment (ALE) is in use, refer to the Automatic LinkEstablishment (ALE) section on page 100.
