20 MHz Oscillator (CB17506E)

This crystal oscillator generates a 20 MHz signal. Equivalent transistors such as BF494 and 2N2222 can be used. The stabilizing diodes can be 1N4148.

| Clique na imagem para ampliar |

Battery Voltage Indicator (CB15369E)
This circuit was found in the Intersil Databook. The integrated circuit used is uncommon today. R2 sets...
S meter (2) (CB1440E )
We find this circuit in a radio amateur publication of 1977. Its purpose is to measure the...
Three Tone Oscillator (CB13174E)
This circuit that can be used as a three-tone domestic bell has a traditional configuration that...