Uses of radio
One-way communication was often used in the navy – Morse code. AM radio uses something called amplitude modulation which means that the transmitted signal is made proportional to the sound amplitude captured (transduced) by the microphone – at the same time is the frequency the same. The transmission is thereby affected by lightning and other disturbing sources.
Two-way communication was often used in the Aircrafts during the Second World War with something called VHF AM.
Mobile phones connect to a local cell site that connects people with each other. If a person is at the end of a specific cell site and loses connection it will automatically find the next closes local cell site and the connection between the two phones won’t be lost.
Analog television send the picture in AM and FM. Today however the digital television has taken over the market almost entirely. The quality of the picture is not as good with analog television as it is with digital, this is because digital television could transmit much more data much faster which gives higher resolutions.
The best way to navigate nowadays is with satellites that has precision clocks. With radio a transmitter and a receiver could communicate to determine which position and heading a certain object has.
Radar means Radio Detection and Ranging and detects objects at a distance by sending out radio waves and measuring their bounces of objects. A standard radar updates the search area two to four times each minute. Sometimes radars use the “Doppler effect” to determine how fast objects move.
Radio frequency can generate heat. By mistake the microwave was invented to warm up food and today it’s one of the most used appliances at homes all over the world.
Before the internet armies used radio control to guide missiles and vehicles. This type of control wasn’t so successful with flying vehicles but very successful with locomotives and cranes.