3-tube receiver (T1602E)

Found in a 1949 Radio Electronics, this circuit employs vacuum tubes of the time. Power supply not provided.

Adjustable High Q Notch Filter (CB15815E)
We can implement this filter with more modern equivalent operational amplifiers, since the LM110 is...
LM3914 Overrange Indicator (CB24657E)
This circuit is from an October 1980 Radio Electronics magazine. The circuit indicates when the...
CMOS Two-Tone Siren (CB18974E)
This circuit can be used as a shield when its supply is 5 V. in this case we can exchange the...