This circuit was found in a 90s Popular Electronics. The circuit uses components from that time, intended to receive signals in the range of 150 to 250 kHz.
This circuit was originally designed with the operational 747 which is rare today. However, the...
This circuit was found in a 1975 technical publication. The circuit can be designed with 741...
The TDA2613 is the mono version of the TDA1521A and has pinouts compatible with an integrated...