The complexity and sophistication of the electronic hardware required to recover composite baseband signals in the FM band is beyond the capability of most experimenters. However, modern digital signal processing software, capable PCs, and inexpensive software defined radio (SDR) hardware can now be easily combined to receive the information in these broadcasts. Learn how to combine this hardware, software, and your PC to build SDRs to receive FM radio broadcasts and more.
There are situations where a low output impedance to A headphones is required. This article discusses three different versions of headphone amps to fit your particular application: a stereo amp powered by the power line; a battery-operated mono amp for a crystal set; and a battery-operated amp for a ceramic cartridge.
I decided to make an electronic musical toy as a Christmas gift for my young son. I browsed the Web looking for inspiration and found the stylophone: a miniature analog stylus-operated keyboard that was invented in 1967 by Brian Jarvis. My unique take on it combines music and writing to make learning fun!
This project is a follow-on from my MIDI lyre project featured in the July-August magazine. I’m going to describe how to build a MIDI autoharp. Like the lyre, this is a MIDI controller, so it doesn’t make any sounds itself. Instead, it sends MIDI messages to an external synthesizer. It’s the synthesizer that makes the sounds.
The MIDI Replay stomp box is a powerful configuration and recording device for keyboard players, based on the wonderful MIDI protocol: the standard musical language of over 30 years.
This article explores the design challenges of this real-time system and covers topics such as task scheduling, buffers, parallel computing, dynamic memory management, response time analysis and menu system design.
When my wife and I moved into our current home a few years back, it didn’t have a doorbell. We live on a quiet cul-de-sac, so it really wasn’t a problem as we had few callers. After a while, I installed a wireless doorbell that lasted about three years. Recently, after writing the series of articles on “A Digital Analog — When a PIC Can Replace a 555,” I decided to make one using a PIC.
Magnetic loop antennas are becoming popular today because they can be very efficient for their size, do not need radials (even though most designs are vertically polarized), have useful takeoff angles, and can be easily rotated to peak or null a signal. Here’s how I designed a convenient setup for myself.