These TV channels are called VHF (very high frequency). Other channels called UHF (ultra high frequency) utilize an even higher frequency range of 470 to 1000 MHz. The TV video signal is AM, while the TV audio is FM.

AM was adopted for the transmission of the video part of a TV signal because AM is the least wasteful of the radio frequency spectrum, which is a precious commodity in a wireless environment. FM, though, because of its relative noise-free reception, is used to transmit the audio part of the television signal.

AM broadcasting is radio broadcasting using amplitude modulation (AM) transmissions. It was the first method developed for making audio radio transmissions, and is still used worldwide, primarily for medium wave (also known as “AM band”) transmissions, but also on the longwave and shortwave radio bands.

During the tv transmission , Frequency modulation (FM ) is used for audio transmission and amplitude modulation (AM ) is used for picture transmission. Answer: In Television transmission, FM is used for audio transmission and AM is used for video transmission.

With FM, the frequency (the number of times each second that the current changes direction) of the carrier signal is varied. FM signals have a great advantage over AM signals. Both signals are susceptible to slight changes in amplitude. With an AM broadcast, these changes result in static.

The decline in AM audio was due more to regulation than to method of modulation. One aspect of radio not understood by most listeners is the concept of occupied bandwidth, or the amount of spectrum that a station uses to transmit its signal.

Most AM radio stations are required by the FCC’s rules to reduce their power or cease operating at night in order to avoid interference to other AM stations. However, during nighttime hours the AM signals can travel over hundreds of miles by reflection from the ionosphere, a phenomenon called “skywave” propagation.

Although the heyday of AM radio has passed, it remains an integral part of many lives as a means of communication in third-world countries, or simply tuning in for local news and weather. Amplitude modulation (AM) is by far the oldest form of modulation known.

They’ve been using it since radio started getting widely used in aircraft, and IN ORDER FOR ALL AIRCRAFT TO BE ABLE TO TALK TO ALL TOWERS they have stuck with the same frequency range, channels, and modulation type. Very simply – Using AM will allow even a distant signal to be heard.

This means that it is illegal to listen to anything other than general reception transmissions unless you are either a licensed user of the frequencies in question or have been specifically authorized to do so by an authorized person.

If you wish to talk to the pilot of another airplane, use the air-to-air frequency of 122.75 MHz. It is not considered good etiquette to fill other frequencies with pilot-to-pilot chats. VOR frequencies are between 108.0 and 117.975 MHz, immediately below aviation communication frequencies beginning at 118.0.

The Baofeng radios, notably the UV-5R, UV-5RA, and UV-5RE, did not comply to these rules and on March 13, 2013 the FCC Enforcement Bureau received a complaint alleging that these models were capable of transmitting on land mobile frequencies using external controls and operating at power levels above those specified by …

One of the reasons the Baofeng UV-5R radios may be so inexpensive is they are not aimed at a specific Niche, therefore they save money on big advertisements and promotions like the ham radio equipment manufacturers like Yaesu Icom and kenwood. They also do not test and advance any technology.

There isn’t any “Baofeng ban”. Baofeng makes several other models that are FCC certified for things like GMRS, MURS and Part 90 (public safety and commercial Land Mobile Radio Services). Using non-certified transmitters on those bands is a federal crime.