The first picture is of a rebuilt version of the CA3306 circuit.
Next I tried a TLC5510. The results were a bit noisy as seen in the next picture.
A picture of the TLC5510 screen. The noise might not be the fault of the A to D converter. The noise was cured by synchronizing the clocks.
TDA8703 Analog to Digital converter being tested. At first it did not work until I increased the power from 4.2 volts (from USB) to 5 volts via an AC adapter.
I found a way to synchronize the clocks and thus reduce the amount of glitches! Here is the video.
Here is a Youtube video showing the TLC5510 running without the clock glitches.
Here is a video showing a completed Arduino Oscilloscope with working selection switches.