This is a simple tubed mixer from the 50's. The circuit does not include the power supply and has 3 inputs with independent controls. The tubes are double and the inputs are high impedance.
A modulated (flashing) siren using the four gates of the 4001 integrated is shown in the figure....
May 2017 - Mouser Electronics already has Microchip's new MCP14A0451 and MCP14A0452 integrated...
Mouser Electronics has in stock Texas Instruments Buck controllers LM5145 to operate with voltage...