This is the circuit of the commercial Japanese megaphone of the 60s model DM-218. The circuit uses a compression speaker (horn) and is powered by 4 large batteries. The output power is 2 W.
This circuit was found in an old British publication from 1976. It must be powered with 5 V and...
This midrange filter for sound systems was found in the May 1988 issue of Radio Electronics...
January 2017 - Mouser Electronics already has in stock the Epson TCXO TG2016 crystal oscillators for use...