Practice morse code with a straight key and this simple code practice oscillator. Like the old Boy Scout signal training sets of the 1930’s, this CPO produces both sound as well as light from the front and back. The CPO has adjustable volume and tone controls from 300-1000Hz along with a headphone jack for private listening. It can also drive a positive keying transmitter up to 30V/500mA with the key jack. The kit version has all SMT parts pre-soldered on, just solder the few remaining components and assemble the enclosure.