Home made HF QRP Transceiver

After 20 years  big pause as ham radio, in 2019 decided to start building a homemade 5 bands transceiver using classic superhet configuration.

Did not want to make a SDR, but insted a single 9 Mhz  IF using high end components and a modern touch screen display ontop of Raspberry Pi controller for I/O purposes.

After much trial and error, this is my current config:

  • CW only
  • 80 to 10 M 5 bands
  • 10 W RF constant output.
  • Internal speaker
  • Optical encoder for VFO knob
  • Si5351 as VFO generator
  • Secondary Si5351 as BFO shifting generator (using 2 outputs for same Si5351 will generate crosstalk signals which must be avoided)
  • Analog Device IF preamplifiers / mixers / fast logarithmic detector (AD603 , ADE 1-24, AD8310)
  • Audio variable DSP
  • Analog to digital converter (Raspberry Pi does not have ADC)
  • Arduino nano iambic keyer with BK capabilities.
  • USB interface for computer CAT controll (emulated Kenwood codes)
  • Python language since  Raspberry Pi is running Kivy OS python framework as O.S. (It has it’s own OpenGL videodriver for native 7 inches touch display).
  • USB/LSB/CW 9 Mhz cristal filters

Long story short : Nice piece of transceiver,could be updated via Github ( beta version),low noise profile,easy to operate and incredible receive performance.

Using  DAC controller and a dual gate mosftet for TX amplitude biasing  before PA stage, I have obtain 10 W constant output in all bands.

Total cost just about 500 Euro give or take.I would not recommend this build for beginners.

Will be updated to be Ci-V slave for Icom IC-7300  for diversity reception test (both connected to different antennas but  same headphones , one to left and secondary to right )

The AGC clipping sound has been fixed since but S-Meter is yet to be calibrated, not that I care too much about it. Afterall  not the S-Meter is hearing remote station.

Special thanks to:

  • My father for being my father and opening my eyes about reverse Euclid computing for Python Si5352  parameters
  • Charlie Morris     Zl2CTM  Youtube Channel
  • Jason Milldrum   NT7S       Jason website

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