sBitx

sBitx – Developer’s Edition

The sBitx Article | Operating Manual | Circuit Diagrams and Software | Assembly Manual The sBitx Developer’s Edition was a limited run that sold out. Join the https://groups.io/g/bitx20 for announcements regarding future availability. The circuit and the software is all open source we encourage you to try scratch-building it. The sBitx is a 40 watts, fully open source, high performance HF SDR transceiver with in-built popular modes like the FT8, RTTY, PSK31, etc. 
Fully Assembled and tested sBitx with microphone

Performance from Simplicity

Performance doesn’t have to come with expensive components. A careful application of design principles over inexpensive and readily available parts and modules like the Raspberry Pi and ordinary transistors like the 2N2222s, results in a simple radio that is powerful and yet easily understood. Easy to understand, simple circuit that allows you to modify, enhance or experiment. None of the components cost more than a few dollars. Read the detailed sBitx design paper, download the Circuits and the Software. 

Hackable 

  • Entire development system is on the radio and preconfigured. Start editing the code and run build to see the changes. No need for any external computer to hack this radio.
  • Written in plain C language. If you can read Arduino code, you can code the sbitx too!
  • Simple User Interface encourages you to change the layout, create you own look and feel with your own buttons, screen layouts and macros.
  • Intuitive approach to SDR
  • Understand and learn to do DSP, SDRs. The sBitx’s approach  uses a conventional superhet architecture along with convolution SDR to build the simplest SDR architecture.

The Receiver

The receiver is a hybrid architecture that filters exactly 25 KHz of RF spectrum using an aggressive crystal filter, eliminating the image problems associated with phasing type of SDRs.
  • Passive FET mixer without early amplification with +28 dBm IIP3 
  • 6 pole, 25 KHz bandwidth crystal filter front-end suppresses opposite sideband by 70 db.
  • High dynamic range IF system to preserve all closed spaced signals of digital modes. 
  • General Coverage HF reception
  • Ring free Pass Band Tuning for working CW and SSB without fatigue
  • Audio Recording of brag tapes
  • Automatic decoding of in-built modes like FT8, RTTY, PSK31
  • AGC settings of Fast, Medium and Slow
  • Band stacking VFOs, 4 frequency/modes on each band

Transmitter

The transmitter is a powerful 40 watts output radio for when the going gets tough
  • The PA uses IRFZ24N transistors that can are easily replaced even if you blow them up
  • 40 watts on 80m and 40m, goes down to 20 watts on 15m and 6 watts on 10m
  • 3 section low pass filters for clean transmit output.
  • Two VFOs with split function, incremental tuning.
  • Speech compression for SSB
  • Better than 43 dbc suppression of spurious emissions

Brief Specifications

Frequency Receive; 100 KHz to 30 MHz, Transmit: 3500-4000, 7000-7300,10000-10150, 14000-14350, 18000-18200, 21000-21450, 24800-25000, 28000-29700 (KHz)
Power Output 40 watts on 80M and 40M, 30 watts on 30M and 20M, 20 watts on 17M and 15M, 10 watts on 12M, 6 watts on 10M
Power Consumption Receive: 1.5 A Transmit : 10 A
VFOs Two VFOs A and B, with split operation, tunable in steps of 100 KHz, 10 KHz, 1 KHz, 100Hz and 10 Hz. Direct frequency entry from the keyboardRIT : Receiver incremental tuning +/- 25 KHz Split operation: Cross band
Band stacking 4 frequencies/modes on each band, selectable by repeatedly pressing the band switch.
Modes  USB, LSB, CW, CW-Reverse, RTTY(45), PSK31, FT8 (with on-display decoding and sending) 2-Tone test signal for intermodulation testing and PEP measurements.
Logging Built-in logger with N1MM format macros, Auto incremental Exchange number of contesting.
Recording Record your QSOs int WAV format files
Third party apps Fldigi: FLdigi intergrated via xml-rpc. QRZ.com: Queries your contact’s callsign on qrz.com
Receiver Noise Figure: +15 dB, IIP3 : +28 dBm
Transmitter Upto 40 watts of variable output power Better than -43 dBc suppression of spurious signals Speech compression on SSB
Telnet  Connects to RBN and DX clusters from the radio
 

Buy the Fully Assembled sBitx ($499 USD)

Out of Stock

A fully tested and working sBitx with the original 7 inch Raspberry Pi display and 2 GB Raspberry Pi, all software installed and tested. Included:
  • Fully assembled, working sBitx with preloaded software
  • 7 inch, ten touch, official Raspberry Pi  capacitive display
  • Raspberry Pi 4, 2 GB version
  • 32 GB SD card with the preloaded sBitx, Fldigi software
  • High quality, laser cut, thick aluminum enclosure
  • Large heatsink eliminates the need for noisy cooling fan 
  • Microphone
  • DC power connector

Buy the Basic sBitx ($299) (without the Raspberry Pi, the Display and the Microphone)

Out of Stock

  • A fully tested and assembled sBitx without the Raspberry Pi, the Display and the Microphone that you will have to supply.
  • All the mounting screws, etc. required to mount the Raspberry Pi and the Display (see the Assembly Manual).
  • A 32 GB SD card loaded with the sBitx (to be plugged into the Raspberry Pi)