TTL Counter (CB21360E)

This counter from 0 to 9999 was found in English documentation. The power source must be 5V with at least 1A.

27 MHz receiver (CB19446E)
This receiver was obtained in a documentation from the 90's and is of the super-regenerative type....
Line Driver (CB24229E)
This circuit couples 600-ohm signals to a line of the same impedance consisting of an amplifier stage....
Tachometer with Direction of Rotation Indicator (CB11572E)
The circuit presented is from an old magazine having been translated and published in a national...