richardeberhardt
- Sep 30, 2022
- 4
- Joined
- Sep 30, 2022
- Messages
- 4
My goal is to learn enough electronics that I can diagnose my tape recorder (circa 1981) problem - there appears to be a problem with the amplification part of the circuit board.
I read a couple of overview books and decided that, before jumping into the tape recorder problem, I would start off by building a breadboard to replicate the design and implementation of a simple common emitter amplifier.
I chose these two YouTube videos for this purpose:
Theory
Implementation
This is my version of the breadboard

Testing Set Up
Oscilloscope is DSO Shell by JyeTech
Breadboard
Using the iPhone app Signal Gen
Power supply via Arduino
Results
Input Signal

Output Signal

The input measurement showed what I expected it to show.
The output measurement is not what I was expecting
The general shape of the wave is there, but the image is not stable
The measured frequency of the wave goes up - that looks wrong
The Vpp is higher on the output side than on the input side (23mV to 70mV)
Any help would be appreciated
Thanks,
Rich
I read a couple of overview books and decided that, before jumping into the tape recorder problem, I would start off by building a breadboard to replicate the design and implementation of a simple common emitter amplifier.
I chose these two YouTube videos for this purpose:
Theory
Implementation
This is my version of the breadboard

Testing Set Up
Oscilloscope is DSO Shell by JyeTech
Breadboard
Using the iPhone app Signal Gen
Power supply via Arduino
Results
Input Signal

Output Signal

The input measurement showed what I expected it to show.
The output measurement is not what I was expecting
The general shape of the wave is there, but the image is not stable
The measured frequency of the wave goes up - that looks wrong
The Vpp is higher on the output side than on the input side (23mV to 70mV)
Any help would be appreciated
Thanks,
Rich