Radio communications are an important element of emergency supply. Quite naturally, from their effectiveness almost everything depends on how rapidly are found in distress and how time will come help.
23 may 1928, leaving the shore Spitz-Bergen, rose into the air, heading North, the airship Italia. The expedition, led by Umberto Nobile, had to perform a vast program for the study of the Arctic. But on may 26, the radio communication with the airship suddenly ended. The day passed after day, and the expedition had not received any messages. It became clear that the airship crashed.
And now, June 3, 1928, in 19 hours and 30 minutes ham Schmidt from the far North of the village the ascension-Vohma received a telegram: "Itali… Nobile… Fran Uosef… SOS, SOS, SOS terri teno EhH".
The search crew «Italy» were equipped with 10-key expeditions from 6 States. 18 ships and 21 aircraft. Active participant in rescue operations was a Russian Alliance. According to the decision of the Russian government in the North was sent a powerful icebreaker Krasin icebreaker ships Sedov and Malygin. Russian expedition rescued all the rest after the crash of the airship people. Nobile was taken from the ice camp Swedish pilot Lundborg.
So, don’t be at the disposal of the Italians emergency radio transmitter, perhaps they would understand the tragic fate of many polar explorers of the past, forever disappeared in the middle of the Arctic silence.
In our days no ship, no plane, no big expedition does not go without an emergency radio transmitter.
There are many types of emergency radio stations, different in its design, dimensions, range of acts, etc. They provide two-way radio communication at a distance of hundreds of kilometers
For example, in the United States is extensively used manufactured by the company emergency radios AN/PRC-90, which provide two-way communication with the search aircraft flying at an altitude of 3000 m at the distance of 114 km (Robins, 1979). By using the West German radio office pilot in distress, can communicate at a distance of 160 km (Search and rescue, 1971). Portable radio R-855 Mind, used in Russian Called, is among the more successful models. Small size, small weight, comfortable, it is a reliable assistant in distress. To establish a link with the search aircraft (helicopter) extract NAE and extract the radio, connect a cable from the battery, and deploying the antenna to its full length, respexit buttons on the panel.
The distress signal is passed three times, just in sequence of: — three times, a combination of DE — once your call sign twice, latitude and longitude, double-word reception once. After each transmission, the radio is switched to the reception mode. In the 1st day after the tragedy need at times to repeat the signal for 10-12 minutes for the first of each hour, then quit the station is enabled to receive. In the following days after the transfer and three receiving station are advised to switch off, to save power. But as you will hear the sound of the aircraft engine or in the sky appears the plane or helicopter, the station need to quickly turn. A message about the disaster mixed with half to two-minute signal for the actuator. As-needed long-term work station in one mode, by pressing the appropriate button, delaying its release. With emergency shortwave radio group use are slightly different. Expanding the station, turn three times convey a message about the disaster in telephone and Telegraph modes. After each transfer run on admission for 3 minutes. In the 1st day after the occurrence of an emergency first every hour 10 — 12 minutes the machine signal . The rest of the time the station remains on at the reception. First the following day three passed the message about the disaster alternately in telephone and Telegraph modes with transition after each transmission to the reception for 3 minutes. First, every hour for 5 minutes gets automatic transmission signals , and then after five minutes of taking the station off. To power the radios used different batteries: mercury-cadmium, silver-cadmium, silver-zinc and other
When the temperature is +20° batteries provide station energy for 10 to 20 hours of continuous operation or 30 — 60 hours in two-way mode of communication. In the cooler months, the capacity of the battery miniaturized, and sometimes very significantly. That is why they are advised to keep under clothes, sleeping bag, etc. To provide two-way radio communication is very important to correctly choose the location for the transmitter. No need to stay close to steep mountain slopes, embankments, stone or concrete structures, high-voltage lines. It is ideal to transfer from the top of the mound, ridge mountains, the tops of the highest trees. In order to facilitate the search in distress, set Not enabled beacon — automatic device, bespreryvno transmitting broadcast tone-modulated signals. After the activation of the beacon can operate for 20 hours and more than. When released into the water he held afloat inflatable spherical shell. If necessary, the lighthouse, you can unmount, remove the radio from the shell and use it to conduct two-way radio communications with the search aircraft.