HF Air Traffic Frequencies

[alok]

I heard a mention by HF ATC on 5574Mhz ,8834 Mhz and other HF ATC freqs. a thing called "CELL PHONE CHECK" or "CELL CALL" ,followed by two different tones. The airline then verifies receiving this check.

What is this ?

Is it a real cell phone like we are all use too or some special HF cell phone ,used for what ?

Al

 

[nd5y]

That would be selcal (selective calling)
https://www.arinc.com/cf/store/catalog_detail.cfm?item_id=12
http://www.arinc.com/products/voice_data_comm/air_ground_radio_svc/international.html

 

[brandon]

Here is a good site to lookup selcal codes
Selcalweb home page & database search

 

[poikaa]

SelCal codes are used to "wake" up a squelched radio, this is so that the radio remains quiet as there is enough going on in the cabin and the pilot does need need the distractions. Several aircraft can use the same frequency this way with different SelCal codes.
Some history on this.... With business band frequencies on or near the CB radio frequencies SelCal was used in the same way, there were limited channels available. This goes back to about the late 1950s.

poikaa