Everything you need to know to build sBITX – Farhan

VU2ESE – Ashhar Farhan has recently published the complete DIY guide to making his most anticipated homebrewer transceiver – sBitx. Homebrewer community worldwide was looking forward to buying Farhan – SDR Transceiver – sBITX, however, it seems buying a ready-made sBITX will take some time with hfsignal.com

In case, you don’t know – What’s sBitx?

The sBitx is a homebrewer’s SDR radio with integrated digital modes.

  • The maximum power output of 40 watts on 80M and 40M bands, goes down to 20 watts on 15M and 6 watts on 10M.
  • Based on a Raspberry Pi, a WM8731 codec and ordinary components are found in your junk box.
  • Uses a hybrid superhet architecture for high-performance design
  • You can build it for less than $100 in new parts in addition to the Raspberry Pi and Display.
  • The circuit is simple to build without any FPGAs and expensive parts
  • The software is hackable, and modular.

Complete Build Instructions

  1. Download circuit diagram and software from https://github.com/afarhan/sbitx
  2. Here is the Raspberry Pi Image for the sBitx. Download, unzip and burn it into a 32GB SD card.
  3. Read the Operating Manual

Underdstanding Hybrid SDR

The sBitx is an up-converting superhet with the IF at 40 MHz. This eliminates the need for multiple filters, one for each band of operation. As our frequencies of interest are below 30 MHz and the local oscillator is above 40 MHz, the image frequencies are well above 80 MHz. These are easily filtered by a simple low pass filter for the entire HF band. Central to the approach of the sBitx is that we can build a 25 kHz width crystal filter that has a very sharp image rejection. This is now possible with the easily available, low-cost 40 MHz fundamental mode crystals (ABM10AIG-40.000MHZ-2Z-T from Mouser.com).

 

In case you are now really serious to make this sBitx from VU2ESE You should read this first https://www.vu2ese.com/index.php/2022/07/20/the-sbitx-the-sdr-for-the-homebrewer to get started.

PS: This news is sourced from VU2ESE’s Latest Blog on sBitx

 

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