What is the purpose of an FM receiver?
145146
FM Receiver receives a broadcast frequency that can play back in Stereo.....versus AM which can only playback in Mono (1 channel).
405837
You need to have recorded the power over a range of frequencies and ploted the Output over the Input. If the chirp signal can be extrapolated into its freqency components possibly you can compare the output to this, otherwise a new set of data points are required.
206010
you should use the same type of transmitter module as you are using for reciever
991778
Like color TV was added to B&W TV in the mid '60s, stereo was added to FM radio several years after FM broadcasting first began.\n\nIn recent years, stereo has likewise been added to AM broadcasting, at least by the FCC. There's no technical reason why stereo can't be added to an AM signal. However, AM lately has been relegated to mostly 'talk radio', instead of music, and very few stations/radio manufactureres have adopted it.\n\nIt's kinda like adding Dolby 5.1 to 8-track tapes...who cares?
989057
As always, the almighty wikipedia answers:\n\nThe superheterodyne receiver (or to give it its full name, the supersonic heterodyne receiver – usually these days shortened to superhet) was invented by Edwin Armstrong in 1918.\n\nThe super heterodyne principle, as used in radio receivers, allows certain obstacles in high-performance radio design to be overcome. Tuned radio frequency (TRF) receivers suffered from poor frequency stability, and poor selectivity, as even filters with a high Q factor have a wide bandwidth at radio frequencies. Regenerative and super-regenerative receivers offer better sensitivity but suffer from stability and selectivity problems.\n\nIn radios using the principle, all signal frequencies are converted typically to a constant lower frequency before detection. This constant frequency is called the intermediate frequency, or IF. In typical AM (Medium Wave) home receivers, that frequency is 455 kHz, for FM VHF receivers, it is usually 10.7 MHz.\n\nHeterodyne receivers "beat" or heterodyne a frequency from a local oscillator (within the receiver) with all the incoming signals. The user tunes the radio by adjusting the set's oscillator frequency. In a mixer stage of the receiver, the local oscillator signal multiplies with the incoming signal, producing beat frequencies both above and below the incoming signal. The mixer stage produces outputs at both the sum of the two input frequencies and at the difference. Either the higher or the lower (typically) is chosen as the IF, which is amplified and then demodulated (reduced to just audio frequencies through a speaker)....\n\nThe advantage to this method is that most of the radio's signal path has to be sensitive to only a narrow range of frequencies. Only the front end (the part before the frequency converter stage) needs to be sensitive to a wide frequency range. For example, the front end might need to be sensitive to 1–30 MHz, while the rest of the radio might need to be sensitive only to 455 kHz, a typical IF frequency.
10500
I think the previous answer is geared towards channel allocation and not bit rate vs bandwidth.  I will try to clarify the issue.\n\nFirst, you must understand how FM works and how a digital signal converts to FSK (frequency shift keying).  Therefore I will use a simple example.\n\nEach bit takes up some frequency.  For example, the bit '1' could take up 5 Hz carrier frequency on the bandwidth spectrum and '0' could take up 6 Hz on the bandwidth spectrum.  Therfore, there is a seperation of 1 Hz between bits.  \n\nIf I send a '1' followed by a '0' then on a meter I should see 5 Hz freqency and then a 6 Hz frequency back to back.  We could speed this up to infinity and therefore have these 2 frequencies transmitting all data at infinite speeds.\n\nIn the real world however, a '1' may fall around the 5 Hz frequency but not exactly on it.  It may be about 5 Hz.  Why around 5 Hz and not exactly on it everytime?  Because in the real world we have noise in transmission lines.  Noise can distort the frequency causing it to be a little less than 5 Hz or a little more than 5 Hz.  Imagine if the '1' bit is transmitted but on the receiving end it ends up receieved as 5.5 Hz.  What happens now?  It's not quite 5 Hz and it's not quite 6 Hz.  Noise caused it to move 0.5 Hz away from 5 Hz.  It is in the middle of 5 Hz and 6 Hz.\n\nNow the receiving end has to decide if this is '1' or '0'.  What are the odds the receiving end gets it right?  By slowing down the speed the 1s and 0s that are transmitted , you can hold steady the 5Hz or 6 Hz for that bit.  The faster you go, the less accurate the bit will fall exactly where it should on the frequency.\n\nSo, what are some possible solutions?  Well, you can slow the frequency down or make the frequency seperation larger.  For example, make a '1' be 5 Hz and make '0' be 10 Hz.  Now you have 5 Hz seperation between bits instead of 1 Hz seperation.  Now if the frequency of 5.5 Hz is received, the receiving end can determine that this should have been 5 Hz.  It's highly unlikely it was originally transmitted at 10 Hz.  Therefore, the receiving end detects a '1'.  \n\nBut what have you lost by doing this increase in frequency seperation?  You have taken up more bandwidth.  Every cable has only so much bandwidth and if you have several channels on a cable all transmitting at the same time, you need to limit the amount of bandwidth each channel takes up or you will run out.\n\nSo, therefore, since most companies don't want to backdown on speed to the consumer (you), then they upgrade their technology (i.e. cables) to higher bandwidth cables such as fiber optic cables.\n\nI hope this helped.  Others, please feel free to expand on this topic.  I've only discussed FSK modulation.  Other techniques such as PSK, ASK, QPSK, bit stuffing, NRZI, CRC, and FEC codes can improve bit rate over channels.\n\nYou can read more about bandwidth limits.  Shannon and Hartley came up with a theorem which still holds today and is used quite extensively.  I even know someone who worked with Shannon at Bell Labs back in the day.  Shannon's theorem is C = BW*log2(1+S/N) where C is the channel capacity in bits per second,  BW is bandwidth, S is the signal power and N is the noise power.\n\nWF\nTelecom Engineer
326662
This is (or was) referred to as "Band 2 VHF"  The other VHF bands being used for purposes other than public broadcast. VHF being "very high frequency", higher than HF (= Short-wave) but lower than UHF (Ultra high frequency, as used for example by normal television transmission) \nIf by "Why?", you mean "Why was this frequency selected for this purpose?" I have no expert knowledge, but presume it was a useful trade-off between the bandwidth required for FM audio transmission, and the area a transmitter could cover effectively.
903759
if you have a seperate receiver
995173
Use an RF Spectrum Analyzer to detect and locate any device emitting a radio signal.  Spectrum analyzers tend to be extremely expensive and might have a lengthy learning curve if you're not familiar with radio physics.  There might be cheaper ways, but I doubt there is any other way that is as reliable as a spectrum analyzer.
1045168
All radio signals travel just beyond the horizon if they are not absorbed or blocked.  Lower frequency signals (below the MUF(Maximum Useable Frequency)) are reflected off the earth's ionosphere and travel back down to earth well beyond the horizon.  This may repeat to allow signals to travel around the world.  Most commercial FM signals frequencies are higher than the MUF and just travel into space.  Meteors and weather events can reflect or duct high frequency signals beyond the horizon  on occasion.
903171
Basic information used in AM is amplitude: that's the size from top to crest of the electromagnetic wave used to carry signal from the radio station to your receiver set. This amplitude varies  according to sound. \nIn FM it's the frequency : that's the degree to which waves in the electromagnetic wave  are compressed together. for example, tighly compressed wave represent a high pitch (violin) , low compress a bass sound...\nEither are used as coding techniques to get the signal into a wave sent from emitter to receiver in communications
27846
Modulation is used in communications because the frequency of the signal must be high enough to travel through the air over great distances.  The power necessary to send a low frequency signal, such as your voice, hundreds of meters away would be too much.  Increasing the frequency by modulating onto a carrier frequency allows us engineers to decrease the required power to send that same message.  Hope this helps.
151211
The voice / music is modulated (FM: Frequency or AM: Amplitude), once the signal is modulated it is amplified and trasmitted to an Antenna that amplifies the signal again in order to reach your radio device.\nYour radio take that signal from the air (it has been atenuated while travling in the air), de-modulate the signal and extract the voice/music to be amplified so you can listen what is being played at radio station...\nThis is the basics, but there are many things involved in a broadcast process...
481454
ADF's detect an electric field and a magnetic field which are perpendicular in space and their amplitudes vary sinusoidally with time. The magnetic field induces a voltage into the windings of the ADF loop antenna. By measuring the phase difference between the windings the ADF is able to determine the direction of the beacon. \n\nPutting beacons around the house and using ADF to navigate turns out to be expensive and inefficient as GPS and proximity sensors are available and work better.
285555
Satellites use non-linear amplifiers to relay signals back to earth.  Using AM for any type of transmission through the satellite would heavily distort the AM signal and make the signal have very poor quality.\n\nVideo, or more accurately TV signals used to be exclusively distributed via satellite using FM because of its constant envelope characteristic made them largely impervious to the amplitude distortions caused by the non-linear amplification of the satellite.  \n\nHowever, increasingly more video (TV) transmissions are using digital transmission schemes.  Here the baseband TV signal is digitized into some bit format and the bits are used to phase-modulate (PM) the carrier. When PM is digitally modulated it is known as Phase Shift Keying or PSK. This also has a constant envelope characteristic like FM and PM making it suitable for the non-linear amplification of the satellite.\n\nSatellite amplifiers are becoming more and more powerful as the technology improves.  They also are becoming more linearized.  This is allowing digital transmissions to utilize a combination PSK and AM technique known as APSK or sometimes, QAM (Quadrature Amplitude Modulation).  Using these techniques requires the satellite amplifiers to be used at much less than their full power, so they are linear and do not cause large amplitude distortions.  This is done because these newer techniques allow more bits/sec to be transmitted on the satellite channel.  This allows higher quality video (HDTV for example) or just more video signals per satellite channel.
212368
Oscillation and Modulation of waves produces FM Radio waves. Here is a site which has some good and simple circuits. But remember Transmitting Radio Waves without a license is illegal in most countries..
150565
They are two ways of modulating a carrier wave to carry digital, i.e. binary, information.  In ASK the amplitude of the signal is varied between two levels to indicate a one or zero (on/off keying is a special case of ASK where one of the amplitudes is chosen to be 0).  In FSK the frequency is varied to indicate ones and zeros.  Both are applied in broadcast radio communications and wired data transmissions.  FSK is less suceptible to interference, like FM signals in general.