How an Amplifier works - amplifier with gain control

Gregory demonstrates how an amplifier works.

IF amplifiers in transmitter and receiver chains commonly need a way of gain control. When used if amplitude detector, these amplifiers have are called AGC - Automatic Gain Control - systems.

SSB radios are an example of linear systems that use IF amplifiers for overall amplitude control, maintaining linearity from end-to-end.

Amplifier for IF frequencies are used in cascade for high gain in many transceiver topologies. However, the gain needs to not exceed limits where saturation of the system occurs. The usage of IF amplifier in AGC loops controls the maximum gain, preventing saturation and non-linear behavior of others stages.

Support the channel, becoming a Patron: https://patreon.com/allelectronics

00:22 - Introduction 01:08 - Amplifier prototype 02:56 - Current controlled gain 04:04 - Circuit schematics 05:52 - How an amplifier works 08:28 - Amplifier variable gain 10:20 - Approximate gain 11:38 - Autotransformer 14:54 - Transistor biasing ... https://www.youtube.com/watch?v=ewYBc1jBDGM