As a first dabble into amateur radio projects, I decided to build a Morse code practice oscillator. I searched around for a suitable schematic that my scrap-bin could supply all the parts for. In the end I settled on a simple 555 based circuit from the ARRL, found here. The circuit produces a square wave […]
Several well known audio/electronics distributors sell inline XLR audio attenuators. Typical values sold are -10 and -20dB. I had a need for -30dB so took one apart to change the internal resistors. The theory of operation is that since balanced audio has two equivalent signals of opposite phase, a resistor tying hot and cold together […]