The circuit shown is from the National Semiconductor Linear Applications Handbook of 1994. using ADC0808. The circuit can handle data from up to 4 transducers with an 8-bit output.
This low noise preamplifier has a gain of 19 dB in the 30 MHz band. The circuit is from the 80s....
The transformer of this experimental circuit, which appears in other versions on the website, is...
This circuit is from a 1968 documentation using one of the first integrated circuits available at the...