I started a topic on this issue just a few weeks ago in the ATC-forum.
Why isn’t SELCAL used to contact us on 121,5?
A lot of pilots and ATCO's don't know that SELCAL works perfectly on VHF and thus also on 121,5! (read about it in the ATC-topic!)
A selcal signal is just an (audible) audio tone of a certain frequency! To send one you need a) an encoder and b) a transmitter. There is an app for android and iOs that works as a selcal encoder!
Play store selcal encoder
Selcal encoder for iOS
You simply tap the selcal code in the app, hold the mike very close to the loudspeaker, push the transmit button and tap execute in the app and there you have your selcal signal.
It really works!! (I tested it a few times
)
Listening to 121.5 over Europe is distracting to the primary job because of all the rubbish that people say on it.
With modern ATC suites, surely it wouldn't be that technologically difficult to add an option to the ATCO's screen to bring up a SELCAL option to call an aircraft. After all, if a geek can program a smartphone app in a few hours, surely a function could be dropped on to ATC center systems?
And heck, I would even hope that the ATCO tries the app on a smartphone before scrambling a fighter in a lost comm situation!!
It would be so useful!