This circuit uses an amplifier from National Semiconductor, uncommon nowadays. The numbers in parentheses are for the second channel. The circuit is suitable for old tape recorders.
This booster for listening to signals in the range from medium waves to 30 MHz was found in a 1998...
In the figure we show our first circuit that consists of a simple touch switch capable of driving a...
Using a 7400 we have a short-wave transmitter from 4 to 9 MHz, shown in the figure. The coil...