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.

WWV Converter (CB9329E)
With this converter it is possible to tune the signals of the 15 MHz WWV.in AM receiver. WWV is...
100V Negative power supply (CB21182E)
This negative voltage source was found in a Popular Electronics from the 90's. The transformer has 120V...
Acoustic Pickup Preamplifier (CB13838E)
This circuit is from the Audio Handbook of the National Semiconductor of 1977. Its purpose is to...