741 Filter (CB24265E)

The 1 kHz tuned filter shown uses a 741 op-amp. The components can be re-scaled to suit the desired frequency.

Switch for Oscilloscope (CB22575E)
This circuit from a June 1957 Radio Electgronics is for oscilloscopes of the time with a maximum...
1-Transistor MW Radio (CB18531E)
This simple receiver for listening on a crystal phone tunes the range of medium waves. The circuit...
Two-Wave Radio (CB16395E)
This circuit in a receiver that allows the capture of distant stations with short waves. The...