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.
I suspect you mean an "Intermediate Frequency transformer", or IF transformer. Superheterodyne (Or superhet) receivers convert the frequency of an incoming signal to a special frequency called the "Intermediate Frequency" or "IF". Most of the amplification takes place in the IF Amplifier which usually has several stages. Each of these stages is coupled to the next stage by a tuned transformer called an IF transformer. For AM receivers, the Intermediate frequency is usually 455 KHz, and for FM receivers it is usually 10.7 MHz. These transformers are usually about 20 turns of Litz wire on a plastic former with a dust-iron adjustable core. It sits in a little metal shield can.
for better output,and low impedance.!@
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.
NTSC TV IFs:video, 45.75MHzchroma, 3.58MHzaudio, 4.5MHz
The intermediate frequency in the superheterodyne receiver is chosen as the desired compromise between sensitivity and selectivity. 455kHz is used in AM broadcast applications, while 10.7mHz is used for FM. The IF stage is tuned for a steep skirt passband at that frequency, allowing only the desired heterodyned (shifted) input signal to make it through to the demodulator.
I've seen 455kHz, 10.7MHz and 70MHz intermediate frequencies. There is, however, no law that dictates the IF you run...some very sensitive receivers even use multiple IF stages.
The most common i.f. for a medium waveband receiver is 455kHz, and it has a bandwidth of 8kHz.
what is the reasion of using intermediate frequency in television system
41.11111ghz
In communications and electronic engineering, an intermediate frequency (IF) is a frequency to which a carrier frequency is shifted as an intermediate step in transmission or reception. [1] The intermediate frequency is created by mixing the carrier signal with a local oscillator signal in a process calledheterodyning, resulting in a signal at the difference or beat frequency. Intermediate frequencies are used in superheterodyne radio receivers, in which an incoming signal is shifted to an IF for amplification before final detection is done. The intermediate frequency stays the same for all signals, for example 455 kHz in an AM broadcast receiver.Conversion to an intermediate frequency is useful for several reasons. When several stages of filters are used, they can all be set to a fixed frequency, which makes them easier to build and to tune. Lower frequency transistors generally have higher gains so fewer stages are required. It's easier to make sharply selective filters at lower fixed frequencies.
If=lo-rf
intermediate frequency
Intermediate frequency transformers can be either step-up, step-down, or 1:1. The term "intermediate frequency" relates to the frequency of operation, and not to the voltage or current conversion ratios. An "intermediate frequency transformer" is a special purpose transformer used for filtration purposes in radio reception, rather than voltage or current conversion, though a step-up or step down turns-ratio may be used in the design.
intermediate frequency transformer (ift) acts as a band selective n/w. the ift which is 455 khz is then given to IF amplifiers which is then given to detector.
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.
AM (amplified modulation) radio contain the intermediate frequency transformer.it has IF to mixed the carrier signal into local oscillator signal in a process called heterodyning, resulting in a signal at the difference or beat frequency. Intermediate frequency are used in superheterodyne radio recievers, in which an incoming signals is shifted to an IF for amplication before final destination is done.