What components is represent by the U1a - U1d?? can it be replaced by some random IC 14 pin or .... and what the sweep amplitude and noise amplitude component??
U1 is a four amplifier op-amp chip, there are loads to chose from depending on many factors it rather depends on what this circuit is being used for. The amplitude components are potentiometers.
If you going to build this circuit just remember that it doesn't show the power connections to U1 and these need to be connected.
Thx pwdixon. This circuit was use to build a cell phone jammer. About the potentiometers there are a lot of types for 1k Multi-turn right? is there any different between them? When i was about to buy them they give 3 choices for it.
Sorry but I don't feel I can be of any more assistance on this. Please be warned that in many countries including the UK phone jammers are regarded as illegal.