echo sounder - sonar for yachts

echo sounder elektor june 1984 F. Kuhnke and P.W. Flutters echo sounder sonar for yachts sonar is an acronym of sound navigation ranging MMV - rnonostable multivibrator FF flip-flop (bistable multivibrator) Figure 2. The block schematic is self-evident: the neon lamp has been replaced by a digital display. Underwater sound projector and hydrophone are housed in a common case, while the transmitter and receiver are contained in one IC. Furthermore, a "shallow depth" alarm has been provided. In the past, sounding, that is, measuring the depth of the sea bed, was carried out by a weighted line, the sounding-line. Nowadays, these are found almost ex- clusively on board yachts only. They con- sist of a ball of lead (the weight) and a line that has been marked suitably at regular intervals, so that when the lead touches the sea bed the depth can be read off the line. The big disadvantage of such a sounding-line is that it can only be used at low speeds and at shallow depths. The echo so...