Overvoltage Indicator (CB22007E)

Using a CA3130 operational amplifier, this circuit drives an LED when the voltage exceeds the value set in VR1.

Alarm (CB24803E)
This 555 IC circuit was found in June 1984 Radio Electronics magazine. This circuit detects a...
FET and Bipolar Preamplifier (CB13754E)
We found this circuit in a 1976 publication for radio amateurs. It was originally intended for use in...
Integrated Circuit MC1648 Transmitter (CB19456E)
The integrated circuit used in this small transmitter is not very common today. The coil has its...