CCIR Selcall

CCIR Selcall
Frequencies	30 MHz,800 MHz
Frequency Range	30 MHz - 800 MHz
Mode	NFM
Modulation	MFSK
ACF	—
Emission Designator	—
Bandwidth	5 kHz
Location	Worldwide
Short Description	CCIR selcall consists of CCIR-1, CCIR-2, and PCCIR, which are 5-tone selcall modes for VHF/UHF radios. CCIR-1 and CCIR-2 only differ in the tone duration, and PCCIR only differs in the group, reset, and repeat tone frequencies.
I/Q Raw Recording	—
Audio Sample

CCIRComité Consultatif International pour la Radio (Predecessor of the ITU-R) Selcall consists of CCIRComité Consultatif International pour la Radio (Predecessor of the ITU-R)-1, CCIRComité Consultatif International pour la Radio (Predecessor of the ITU-R)-2, and PCCIR, which are 5-tone selcall modes for VHFVery High Frequency (30-300 MHz)/UHFUltra High Frequency (300-3000 MHz) radios. CCIRComité Consultatif International pour la Radio (Predecessor of the ITU-R)-1 and CCIRComité Consultatif International pour la Radio (Predecessor of the ITU-R)-2 only differ in the tone duration, and PCCIR only differs in the group, reset, and repeat tone frequencies. CCIRComité Consultatif International pour la Radio (Predecessor of the ITU-R)-2 is also known as CCIRComité Consultatif International pour la Radio (Predecessor of the ITU-R)-7, because CCIRComité Consultatif International pour la Radio (Predecessor of the ITU-R)-2 is based on CCIRComité Consultatif International pour la Radio (Predecessor of the ITU-R)-7 recommendations; CCIRComité Consultatif International pour la Radio (Predecessor of the ITU-R)-1 is based on CCIRComité Consultatif International pour la Radio (Predecessor of the ITU-R)-1 recommendations. CCIRComité Consultatif International pour la Radio (Predecessor of the ITU-R) stands for Comité Consultatif International des Radiocommunications, which has now become the ITU-R.

Selcall (selective calling) is a type of squelch protocol used in radio communications systems, in which transmissions include a brief burst of sequential audio tones. Receivers that are set to respond to the transmitted tone sequence will open their squelch, while others will remain muted.

CCIRComité Consultatif International pour la Radio (Predecessor of the ITU-R)-1 has a 100 msmilliseconds (.001 of a second) tone duration per tone, where CCIRComité Consultatif International pour la Radio (Predecessor of the ITU-R)-2 has a 70 msmilliseconds (.001 of a second) tone duration. Both have 16 tones to choose from, but only send bursts of up to 5 tones. The bursts transmit right before a radio transmission. Each tone corresponds with either a number or letter, as denoted by the table below. This signal was primarily used in Europe, specifically the Swedish and Turkish police forces.

PCCIR[edit]

PCCIR shares the same tone frequencies as CCIRComité Consultatif International pour la Radio (Predecessor of the ITU-R)-1 and CCIRComité Consultatif International pour la Radio (Predecessor of the ITU-R)-2, but changes the frequency of tone for the Group (A), Reset (C), and Repeat(E) tones. PCCIR also lacks an F tone, so it only has 15 tones. Each tone has a 100 msmilliseconds (.001 of a second) duration.