Radio: Difference between revisions

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*BPF:
*BPF
:*LPF+HPF=BPF
:*What frequency range?
:*What frequency range?
:*How to implement?
:*How to implement? RL? RC? Do I need something more?


*Amplifier
*Amplifier
Line 9: Line 10:
:*What frequency range?
:*What frequency range?
:*How to implement?
:*How to implement?

*Oscillator:
*Oscillator:
:*Outputs a logic high and logic low. What is the best way to convert this to a co/sine wave (multiplex?)
:*Outputs a logic high and logic low. What is the best way to convert this to a co/sine wave (multiplex?)
Line 16: Line 17:
*Frequency Range:
*Frequency Range:
:*FM is most likely too high to create
:*FM is most likely too high to create
:*AM radio (car stereo) is about right. Find a station you want to tune to
:*AM radio (car stereo) is about right. Find a station you want to tune to. KFBK 1530?
:*AM is allowed +- 5kHz
:*96kHz of bandwidth (due to what the audio card can sample)
:*96kHz of bandwidth (due to what the audio card can sample)
:*SI570 can create a number of frequencies


*Notes to organize:
:*Switching Regulator
:*SI570, KN9YIG
:*Johnson counter
:*Jumper selectable band pass filter?
:*http://www.sdr-kits.net/USB/USB_Description.html
:*Softrock is taking up about 40mA, USB provides 100mA for USB2, and up to 500mA for a high-powered USB 2.0 bus.
:*Pick a logic family and stick with it: CMOS?
:*Quad Analog switch for the multiplexer (Sine/Cosine). 74(V)HC4066 is one of them
:*The 74VHC4066 doesn't go high enough. We need to use a Frequency Mixer instead, http://yu1lm.qrpradio.com/HF-VHF%20SDR%20receiver-part1-YU1LM.pdf

*Book questions
:*Example 9.12, work through the math please
:*Can oscillators produce sine waves without needing a square wave? Do we need to have potentiometers instead of resistors to make sine waves not clip?

*Class note questions
:*What does LO stand for? Local Oscillator
:*http://www.microwaves101.com/encyclopedia/mixerwaveforms.cfm

Latest revision as of 16:55, 8 April 2010

  • BPF
  • LPF+HPF=BPF
  • What frequency range?
  • How to implement? RL? RC? Do I need something more?
  • Amplifier
  • Do we need an amplifier? Is the incoming signal large enough?
  • LPF:
  • What frequency range?
  • How to implement?
  • Oscillator:
  • Outputs a logic high and logic low. What is the best way to convert this to a co/sine wave (multiplex?)
  • What value are we looking for?
  • Frequency Range:
  • FM is most likely too high to create
  • AM radio (car stereo) is about right. Find a station you want to tune to. KFBK 1530?
  • AM is allowed +- 5kHz
  • 96kHz of bandwidth (due to what the audio card can sample)
  • SI570 can create a number of frequencies


  • Notes to organize:
  • Book questions
  • Example 9.12, work through the math please
  • Can oscillators produce sine waves without needing a square wave? Do we need to have potentiometers instead of resistors to make sine waves not clip?
  • Class note questions