The first use for the diode was the demodulation of amplitude modulated ( AM ) radio broadcasts.

In AM modulation the receiver tracks the signal strength of the AM signal as the basis for demodulation.

There are forms of AM in which the carrier is reduced or suppressed entirely, which require coherent demodulation.

The software architecture identified standard interfaces for different modules of the radio: " radio frequency control " to manage the analog parts of the radio, " modem control " managed resources for modulation and demodulation schemes ( FM, AM, SSB, QAM, etc.

TV-guides tend to list nightly programs at the previous day, although programming a VCR requires the strict logic of starting the new day at 00: 00 ( to further confuse the issue, VCRs set to the 12-hour clock notation will label this " 12: 00 AM ").

This intense math program requires that students take summer classes, including Saturdays from 7: 00 AM to noon, taxing for even the most devoted among them.

They begged for mercy and Mr. Krupp gave them set of rules and requires them to spend every spare minute of their day, beginning at 6: 00 AM., catering to his every whim.

Digital Radio Mondiale has had much more success in creating an AM system, and one that could be much less expensive to implement than any proprietary HD Radio system, although it requires new frequency.

In the US, the Federal Communications Commission ( FCC ) requires AM / FM radio and TV stations without a Low Power FM ( LPFM ) license to transmit with at least 6000 Watts of power.

One map in particular (" 5 AM ") requires the cooperation of multiple players to access and complete.

Radios for shortwave reception generally have higher performance than those intended for the local AM or FM broadcast band, since dependable reception of shortwave signals requires a radio with increased sensitivity, selectivity, and stability.

Digital Radio Mondiale requires digital detection circuitry not present in conventional AM radios to decode programming.

simple: AM

A simple form of AM, often used for digital communications, is on-off keying: a type of amplitude-shift keying in which binary data is represented by the presence or absence of a carrier.

Though SSB uses substantially less bandwidth and power, it cannot be demodulated by a simple envelope detector like standard AM.

It is a compromise between AM and SSB, allowing simple receivers to be used but requiring almost as much transmitter power as AM.

One of the advantages of AM is that its signal can be detected ( turned into sound ) with simple equipment.

They may use simple modulation schemes such as AM or FM, or more complex techniques such as digital coding, spread spectrum, and so on.

Lenat claimed that the system was composed of hundreds of data structures called " concepts ," together with hundreds of " heuristic rules " and a simple flow of control: " AM repeatedly selects the top task from the agenda and tries to carry it out.

As a simple switch registering the presence or absence of radio waves, the coherer could detect the on-off keying of wireless telegraphy transmitters, but it could not demodulate complex waveforms of audio ( AM ) broadcasting, which began to be experimented with in the first years of the 20th century, which required the radio signal to be rectified.

Portable radios include simple transistor radios that are typically monoaural and receive the AM, FM, or short wave broadcast bands.

The same SDR that one minute is demodulating a simple AM broadcast may also be able to decode an HDTV broadcast in the next.

This simple change overcame the prevalent AM radio censorship of the era, and got the Shadows of Knight's cover version of the song onto the playlist of WLS, which had censored the original.

A simple stone cross with the inscription on the pedestal reads: " ROLAND ALLEN, CLERK IN HOLY ORDERS, 1868-1947, I AM THE RESURRECTION AND THE LIFE SAITH THE LORD "

Besides being simple, power-efficient and compatible with legacy equipment, AM and SSB permit stronger stations to override weaker or interfering stations, and don't suffer from the capture effect found in FM.

Known by the simple callsign WCKS, the station was forced to use WCKS-FM from 2004 through 2006 when AM radio station WNSI was acquired by the Gradick family and its callsign changed to WCKS.

The New York Times reported, " Characterized by a strong bass, a simple melody, and terse repetitive lyrics ...' Disco ,' as this music is called ... is becoming increasingly popular on AM and FM radio stations.

Using just a simple AM radio, one can easily hear signals from the most powerful stations propagating hundreds of miles at night.

Note that the RF signal modulation is inverted compared to the conventional AM: the minimum video signal level corresponds to maximum carrier amplitude, and vice versa.

RCA manufactured an AM broadcast transmitter employing a single class-C low mu triode with an RF efficiency in the 90 % range.

Since the final RF amplification is now concentrated in a single sideband, the effective power output is greater than in normal AM ( the carrier and redundant sideband account for well over half of the power output of an AM transmitter ).

The front end of an SSB receiver is similar to that of an AM or FM receiver, consisting of a superheterodyne RF front end that produces a frequency-shifted version of the radio frequency ( RF ) signal within a standard intermediate frequency ( IF ) band.

In radio applications, the AFSK-modulated signal normally is being used to modulate an RF carrier ( using a conventional technique, such as AM or FM ) for transmission.

For AM signals the tube also functions as a detector, rectifying the RF signal to recover the audio modulation ; for this reason the circuit is also called a regenerative detector.

A low-pass filter in the audio amplifier filters the quench and RF frequencies from the output, leaving the AM modulation.

On the standard AM broadcast band, transmission power is limited by 100 milliwatts of DC input power to the final RF stage, ( with restrictions on size, height and type of antenna ) or, alternatively, under 15. 221, if the AM transmission originates on the campus of an educational institution, the transmission can theoretically be any power so long as it does not exceed the field strength limits stated in 15. 209 at the perimeter of the campus, 24000 / f < sub > kHz </ sub > µV / m.

** RF transmitter maintenance-IOT UHF transmitters, solid state VHF transmitters, solid state MF transmitters ( AM radio ), tube type VHF and MF transmitters.

FT-107 supports SSB, CW, AM, and FSK modes ; all HF bands have a maximum 100 watt RF output.

The solar system uses both CPV ( SolFocus ) and PV ( Premier Power ) arrays and provides about 17 Kilowatts, or 33 % ( one third ), of the radio frequency ( RF ) power output from the 50KW transmitter ( although transmitter power requirements are up to twice the transmitted power of an AM station ).

Only one graffito escaped the purge, and still remains as of 2005 ; an electronic diagram for the RF output stage of a pirate AM radio station on the back of the bathroom medicine cabinet door.

RF shielding is also used to protect medical and laboratory equipment to provide protection against interfering signals, including AM, FM, TV, emergency services, dispatch, pagers, ESMR, cellular, and PCS.