Electronic Morse Key (CB7313E)

This circuit was found in the magazine of radio amateurs 73 in a 90's edition. The components are current and the transistor is of general use.

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Crystal Colpitts Oscillator (CB13853E)
This circuit is from the National Semiconductor 1977 FET Databook. The FET can be BF245 or MPF102...
Adjustable time chaser (CB6794E)
This circuit was obtained in a 1967 Electronics World. The components are still common today, the...
Mini-Buzzer (CB459)
This circuit uses a piezoelectric transducer to produce sounds like a buzzer. Frequency is...