This sophisticated remote field strength meter circuit was found in a 73 magazine for radio amateurs from the1990s. The circuit measures signals in the 1650 kHz range.
September 2017 - Microchip's MCP6411 operational amplifiers for frequencies up to 1 MHz are in...
We found this circuit in a 70s publication. Transistors are general-purpose types of the time. The...
This receiver circuit was found in a Hands On Electronics from the 90s. The circuit uses a PLL...