This circuit appeared in Amateur Radio Today in an issue and was found in a 1995 issue. The circuit is for the AM band up to 3 MHz. The transistors are general-purpose.
This circuit makes use of an operational amplifier from the 80's. The circuit can be implemented with...
When the power is cut off, this circuit keeps the flashlight on for a while, allowing it to be...
Using the CK722 this directional photometer was published in Radio Electronics magazine in July...