This 10 A solid state relay was found in a 1980s documentation. It can work as a shield and implemented with modern equivalent transistors.
We found this circuit in an old documentation for hams. In it we have the way to use a varicap to...
Found in an 80's documentation this circuit uses an integrated from the uncommon era today. Other...
This circuit is stabilized by a thermistor or NTC with a resistance between 2 and 5k. The signal is...