audio circuits

audio circuits

Operating Modes : Digital Modes

• Ribbit digital text messaging mode for HF/VHF/UHF - Ribbit is a novel digital text messaging mode for VHF/UHF communications for recreational and emergency use which radically increases the density of information transmitted by spectrum used. It leverages the computing power of the modern smartphone to increase the capabilities of any Handy Talkie without requiring any additional hardware or cable. A Ribbit message is fixed in duration at 1250 milliseconds. It is sent over audio modulation with a 2kHz bandwidth centered on 1.5kHz. It is preceded by 400ms of white noise to open analog squelch circuits.
  [ Hits: 133 | Votes: 1 | Rating: 10 ]

• Transistor Audio Preamplifier Circuits - Design Guidelines for Bipolar Transistor Audio Preamplifier Circuits By Mike Martell N1HFX
  [ Hits: 1815 | Votes: 3 | Rating: 4.33 ]
• Design Guidelines for JFET Audio Preamplifier Circuits - Design Guidelines for JFET Audio Preamplifier Circuits By Mike Martell N1HFX
  [ Hits: 645 | Votes: 4 | Rating: 1 ]

• Designing Op Amp Audio PreAmplifiers - Design guidelines for Op Amp audio preamplifier circuits by Mike Martell N1HFX
  [ Hits: 1643 | Votes: 4 | Rating: 3.25 ]

• Interface for MS_DSP - Minimal interface circuits for receiver and transmitter audio, also for PSK31
  [ Hits: 1556 | Votes: 2 | Rating: 5.5 ]
• Sound Card Interface with Tone Keyer - An improved version of the audio interface commonly used to connect a computer soundcard to a transceiver\'s receive and transmit audio circuits
  [ Hits: 402 | Votes: 0 | Rating: 0 ]