We found this circuit in a Poptronics from 1998. The circuit can be extended to more competitors with another 4011. The power can be made with voltages from 6 to 12 V.
The figure shows how to use a varicap in a conventional tuning circuit. The circuit may be an...
The CUT frequency for this filter is determined by the capacitors. The µA4138 is a quad version of...
The TTL 74123 integrated circuit consists of a monostable that can be configured to generate...