3-tube receiver 2 (T1603E)

Using known tubes, this receiver was found in a Radio Electronics from 1949. The circuit does not include the power supply.

Varicap Variable Frequency Oscillator (CB13088E)
The great advantage of the circuit shown in the figure is the fact that its frequency is...
Heat Detector (CB24901E)
The purpose of this heat detector is to find hot spots on a board or other locations. The sensor is...
Digital Voltage Indicator (CB25335E)
This indicator with the integrated circuits CA3162E and 3161E was published in the July 1990 issue...