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A mixer is a non-linear circuit that multiplies two signals together. If the inputs are sinewaves at frequencies f1 and f2 the output will contain signals at four different frequencies, f1, f2, f1 + f2, and f1 - f2. Some mixers may eliminate some of those outputs and post filtering can remove any other unwanted components. This is the way AM and SSB are typically generated.
Modulation is a more general concept, and depending on the type of modulation you are doing, a mixer may or may not be involved in the modulation process.
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Tell you what an intermediate frequency amplifier do?
The intermediate frequency (IF) amplifier lies between the mixer and the demodulator. The mixer shifts the input radio frequency (RF) signal into the range of the IF amplifier. The IF amplifer is a band pass amplifier, so only RF signals that are the IF frequency distance away from the local oscillator in the mixer can pass through to the demodulator. This process is called the superhetrodyne process.
What is difference between self excited mixer and separately excited mixer?
location of local oscillatorself - oscillator is integral to mixerseparate - oscillator is a physically separate stage
What is the purpose of a local oscillator in mixer?
A local oscillator is a device that generates a sinusoidal signal with a frequency such that the receiver is able to generate the correct resulting frequency, or intermediate frequency (IF), for further amplification and conversion into audio detection. There is one local oscillator in a single conversion super heterodyne receiver where heterodyning or mixing is used to generate beat frequencies, which may be the sum or the difference of two frequencies. The local oscillator is usually adjustable and in step with the increment or decrement in the receiver frequency. For instance, if the receiver is tuned to 1,455 kilohertz (kHz) as radio frequency input (RF-in), the local oscillator frequency (LOF) may be set to 1,910 kHz for a so-called high side injection. The two signals are fed to an electronic device known as the mixer, which derives LOF - RF-in = IF or 455 kHz, which suggests why amplitude modulation (AM) broadcast receivers have about four stages of low-power amplifiers tuneable to 455 kHz.
How much does a concrete mixer cost?
A concrete mixer costs between $1,000 for a entry level model to over $10,000 for industrial models. These mixers are used extensively in construction.
Why intermediate frequency are constant?
The frequency spectrum has been distributed for various purposes. Otherwise, the people may use the frequencies of their choice & there will be wide range of interference. So, in order to ensure proper reception of signals, the standards have been fixed for the transmission of frequencies & also for the intermediate frequency because if the intermediate frequency is varied the overall frequency value will also vary. The intermediate frequency value should be so designed that it should not lie within the range of mixer stage. Otherwise, there is the production of noise signal due to the interference of mixer frequency & intermediate frequency. Also, the intermediate frequency should not be too high. Otherwise, it will reduce the selectivity of the receiver because of increase in bandwidth. Considering all these factors 455 khz is the most suitable intermediate frequency value for an AM receiver.
Tell you what an intermediate frequency amplifier do?
The intermediate frequency (IF) amplifier lies between the mixer and the demodulator. The mixer shifts the input radio frequency (RF) signal into the range of the IF amplifier. The IF amplifer is a band pass amplifier, so only RF signals that are the IF frequency distance away from the local oscillator in the mixer can pass through to the demodulator. This process is called the superhetrodyne process.
When would a mixer in an AM superhet receiver output be zero?
The mixer output should be a signal at the IF frequency ... generally 455 KHz in an AM radio. It's the difference-frequency between the onboard local oscillator and the frequency of whatever's coming down from the antenna. Expect no RF energy from the mixer when there's no RF energy in the passband of the RF amp section ahead of the mixer ... i.e. nothing being received. If the RF section is wide open across the band, or there IS no RF section and the antenna goes straight to the mixer, and there's no mixer output, then this indicates that either you're on the far side of the moon receiving nothing across the whole AM band, or else your antenna input is grounded and the mixer is shielded.
Does a frequency modulator or mixer change the frequency of an existing wave or does it just generate a new wave with a different frequency?
A mixer produces new waves with new frequencies. In order to accomplish that, it mixes the incoming signal with a locally generated signal, and passes both of them through a non-linear device, like a diode or an amplifier intentionally biased in a non-linear region. The output of any non-linear device is => the original signals at the original frequencies, => plus a new signal at the sum-frequency, => plus another new signal at the difference-frequency. So it doesn't change the frequencies of the original signals. It uses non-linear techniques to create new signals, with frequencies that are mathematically related to the original ones, in a way that can be tightly controlled. Mathematically, a modulator can be understood as accomplishing exactly the same process.
What is function of an oscillator?
A local oscillator is an electronic device used to generate a signal normally for the purpose of converting a signal of interest to a different frequency using a mixer. This process of frequency conversion, also referred to as heterodyning, produces the sum and difference frequencies of the frequency of the local oscillator and frequency of the input signal of interest. These are the beat frequencies. Normally the beat frequency is associated with the lower sideband, the difference between the two.
What is the difference between dough mixer and dough kneader?
a dough mixer combines the ingredients. a dough kneader kneads the dough, preparing it for baking
What is the difference between a good mixer board and a OK mixer board?
Features, realiability and build quality. Pricetag is usually a good hint.
What is the difference between mixer and agitator?
There are slight differences between a mixer and agitator. A mixer has large paddles that thoroughly mix the contents, while an agitator just shakes the contents of the hopper back and forth for less thorough combining.
What is difference between self excited mixer and separately excited mixer?
location of local oscillatorself - oscillator is integral to mixerseparate - oscillator is a physically separate stage
What is the difference between a live mixer and a recording mixer?
A live mixer and a recording mixer are practically the same under small budgets, a live mixers role is to take all the mics and mix them down to a speaker mix with effect sends etc, a recording mixer has to have as many outputs as inputs, for example you want to be able to chance a channel and record it seperatly so you can mix them down. there is not much difference really.
What are the 4 parts to a receiver?
radio frequency amplifier intermediate frequency( If strip) in a superheterodyne radio mixer /demodulator Audio amplifier
What is the purpose of a local oscillator in mixer?
A local oscillator is a device that generates a sinusoidal signal with a frequency such that the receiver is able to generate the correct resulting frequency, or intermediate frequency (IF), for further amplification and conversion into audio detection. There is one local oscillator in a single conversion super heterodyne receiver where heterodyning or mixing is used to generate beat frequencies, which may be the sum or the difference of two frequencies. The local oscillator is usually adjustable and in step with the increment or decrement in the receiver frequency. For instance, if the receiver is tuned to 1,455 kilohertz (kHz) as radio frequency input (RF-in), the local oscillator frequency (LOF) may be set to 1,910 kHz for a so-called high side injection. The two signals are fed to an electronic device known as the mixer, which derives LOF - RF-in = IF or 455 kHz, which suggests why amplitude modulation (AM) broadcast receivers have about four stages of low-power amplifiers tuneable to 455 kHz.
What does fs mean on mixer?
fs may refer to sampling frequency which is the frequecy used to sample an analog signal.
