Difference between revisions of "HW-9 VFO"

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*** Receiver frequency include offset plus RIT
 
*** Receiver frequency include offset plus RIT
 
*** BFO frequency
 
*** BFO frequency
** Band pass filters to turn square waves to sine waves
+
** Low pass filters to turn square waves to sine waves
 
** 27 MHz crystal
 
** 27 MHz crystal
  

Revision as of 20:48, 26 September 2020

This is a work in process - Gathering pieces.

Features

  • Replace HW-9 internal VFO with a digital VFO
    • HW-9 VFO has legendary issues
      • Mechanical issues with vernier
      • Drift due to thermal
      • Lack of resolution
  • Fits within HW-9 VFO Box
  • Controls Tx/Rx/BFO frequencies with rotary encoder
    • 10 Hz steps
  • DD1306 OLED Display
    • I2C Interface
    • "Curved" display
  • Uses RIT control on HW-9
    • +/- 1 KHz RIT
  • Blue Pill Microprocessor
    • Arduino compatible
    • 3.3V
  • Understands band switch for MHz displayed
  • Si5351 Oscillator
    • I2C Interface
    • 3 Outputs
      • Transmit frequency
      • Receiver frequency include offset plus RIT
      • BFO frequency
    • Low pass filters to turn square waves to sine waves
    • 27 MHz crystal

Parts

Blue Pill Card

128x32 OLED

Rotary Encoder/Breakout Board

  • Includes pushbutton Switch
  • Needs R/C filter on output
  • Includes Pull-Up resistors

Si5351 FrequencyGenerator

  • 3 outputs
    • Tx
    • Rx
    • BFO

Low Pass Filters

  • 6 MHz

Libraries

Videos