What is purpose of mixing of signals in a heterodyne receiver?

To heterodyne means to mix to frequencies together so as to produce a beat frequency, namely the difference between the two. Amplitude modulation is a heterodyne process: the information signal is mixed with the carrier to produce the side-bands.

How do you calculate the image frequency of a superheterodyne receiver?

The image frequency is calculated as: fsi = fs + 2 I.F. Image frequency is given by fsi = fs + 2 I.F.

Why if is 455 kHz?

455 was chosen because it was below the 540 end of the AM broadcast band. The 5 on the end was because mixing products of stations spaced 10 apart would not get into the IF and the local oscillator radiation would fall between stations.

How do you signal a heterodyne?

They do this by mixing the television signal frequency, fCH with a local oscillator at a much higher frequency fLO, creating a heterodyne at the sum fCH + fLO, which is added to the cable.

Why is frequency needed?

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.

What is a superheterodyne receiver?

Armstrong called this new receiver (which used heterodyning to translate signals to a fixed, lower intermediate frequency for reception) the “superheterodyne” receiver, as shown in the block diagram in Figure 2. FIGURE 2. Architecture of Armstrong’s superheterodyne receiver.

What is the architecture of Armstrong’s superheterodyne receiver?

Architecture of Armstrong’s superheterodyne receiver. Designing an AM superhet receiver for the commercial broadcast band is a good way to better understand the operation of Armstrong’s superheterodyne receiver. The AM broadcast band contains 117 10 kHz-wide channels spaced between 530–1,700 kHz.

What is superheterodyne design?

Almost a century after its introduction — except for sophisticated approaches such as software radio that involve advanced digital signal processing techniques — Armstrong’s “superheterodyne” or “superhet” design reigns supreme in communications electronics.

How do I read a schematic diagram for a 6×2 receiver?

A schematic diagram like the one for the 6×2 receiver can seem very intimidating at first. The trick is to break down the circuit into its individual parts, and work on each part separately. Below you can either click on a link in the list or click on an area of the schematic diagram to take you to a page that discusses that individual circuit.