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