Dave Richards AA7EE

• Testing Out Different Headsets with a Crystal Set and Assembling a Sound-Powered Headset
  Before building Jim W4LF’s Hobbydyne™ crystal set, I put together an impedance matchbox, for matching the detector diode to a variety of different headsets and earphones, so that I could determine the best ones to use. The world of serious crystal set listening was new to me, so I did some reading up. To give […]
• A Crystal Set Impedance Matchbox
  Growing up as the youngest of 4 boys, I was well positioned to receive all the hand-me-downs. Although that might sound as if I just ended up with second-rate stuff, that was not the case at all. I inherited a lot of great things from my older brothers. I couldn’t have cared less that they’d […]
• A Little WSPR Beacon (Aren’t They All Little?)
  I first tried WSPR out in 2009, with a Signalink USB interface attached to my FT-817 and PC. For anyone interested in QRP and QRPp, the process of being able to decode a signal that is up to about 34dB below the noise level is quite fascinating. Morse code, sent by way of CW, engages […]