Astable 555 (CB21101E)

This 50% duty cycle configuration was found in a Popular Electronics from the 1990s. The operating frequency is given by C1.

Sensitive VHF Wavemeter (CB4119E)
This circuit is more sensitive than the previous one (CB4118E) for using a full wave detector. The...
Active Low Pass Filter (CB6726E)
This circuit was obtained in an American publication of 1970, making use of components of the...
Remote thermometer (CB9487E)
We found this circuit in a 90s Linear Technology documentation. The circuit uses components from...