Rf Amplifier Circuit Am Radio

Noise figure is about 7 db at resonant frequency.

Rf amplifier circuit am radio.

There are no electrolytic capacitors and the three capacitors used can be ceramic or mylar. Am fm radio frequency amplifier this am fm radio frequency amplifier is built with only a few components. The amplified signals are fed to antenna input of the am radio receiver for better reception. It is there to select the wanted frequency and reject some of the unwanted frequencies.

It has about 25 db gain in the frequency rang 88 108 mhz. The 10 meters 27mhz cw radio amplifier is equiped with vn66af transistor produced by siliconix wich has some blf245 fm 88 108 mhz rf amplifier p. The amplifier works well when it is connected to the rest. Trouble shooting an rf stage is fairly straight forward.

Using a signal generator a modulated signal is applied to the antenna terminals and if the stage is working properly the amplified signal will appear in the plate circuit across the interstage transformer t 2 to be passed on the converter stage. The working of the circuit is simple. You can employ 1 4 watt resistors or even 1 2 watt resistors which are easier to manage. Mirror frequency rejection is between 5 db to 9 db.

An input amplifier for a fm radio receiver with rf selection 88 108 mhz has been designed in the radio project. The preamplifier circuit provides a gain higher than 10 in the lw and mw range. The rf amplifier is one of the key areas of any superheterodyne radio receiver and its performance can govern many aspects of the performance of the receiver as a whole. Which makes the project simple and direct.

L1 is wound on the same core as l2 which couples the input signal through c2 to the transistor q1. The rf amplifier circuit and tuning is the first area of the radio receiver that the signal encounters when it enters the radio. Figure 2 19 is the schematic diagram of a typical rf amplifier that is used in an am radio receiver. The circuit can also work for short wave sw range depending on the quality of practical implementation.

However such a receiver need not have an transistor rf amplifier circuit following this tuned circuit. Transistor rf amplifier circuit. In the final part of this chapter you will be shown some typical rf amplifier circuits.