The minimum amount of power necessary to carry out the desired communication.
A radio that receives Frequency Modulated (FM) transmissions.
transmissions
Wavelength
Amplitute Modulation signals. a modulation(mixing)method used in early radio transmissions.in many countries, radio transmissions below 30 Mhz,are still using this method.short wave,medium wave transmissions,and some extent of VHF transmissions are possible in this method.
yes
Yes, they can monitor and decipher.
Earth would appear as a bright source of radio waves to extraterrestrial astronomers due to human-made radio transmissions. These transmissions, including radio broadcasts, satellite communications, and radar signals, create a radio "glow" around Earth that can be detected from great distances in space.
Pennine Radio Limited was created in 1958.
CONTACT! Example (US radio transmission): "Lima 6 this is Mike 6 we have contact over!" Further transmissions would follow...normally with audible gunfire in the background of the radio transmissions.
radio transmissions and observatory purposes
solar flares
The 509 RRG was an Army Security Agency unit [formerly called the 3rd Radio Research Unit] that did radio detection of Viet Cong radio transmissions.