Shortwave Arduino Transmiter with SI5351 and Arduino

Shortwave Arduino Transmiter

This project is about a shortwave trasmitter from 3 MHz to 30 MHz. It uses the SI5351 oscillator from Silicon Labs controlled by Arduino. Also, you can use it with a crystal oscillator. In this case, you will not need the SI5351 devive and Arduino.

The software developed for this project can be freely distributed using the MIT Free Software model.

Copyright (c) 2020 Ricardo Lima Caratti.

Be a member of Facebook group DSP receivers for hobbyists

Content

• Preface

• Your support is important

• Schematics

• Arduino Sketch

• References

Preface

Recently I have been developing some Arduino libraries to control DSP receivers. The main motivation for building this shortwave transmitter is to be able to do experiments and tests during the development of the Arduino libraries for the SI473X, Si4844, AKC695X, KT0915 and others. My current location does not allow good shortwave broadcast reception most of the time. In this case, a small Shortwave (3 ~ 30 MHz) transmitter can be a good tool. Actually you can experiment other frequencies. If you intend to use the SI5351 oscillator version, you can modify the Arduino sketch and change that range.

This project is originally based on the Stefan0719 and SIMPLEST SHORTWAVE TRANSMITTER CIRCUIT EVER projects that use crystal oscillator or ceramic resonator. Instead of a static oscillator, this project also allows you to use a SI5351 signal generator that can be controlled by Arduino. The main idea is to be able to transmit on any frequency in the HF band (3 ˜ 30 MHz). As mentioned earlier, you can try other frequency ranges if you want. See video below.

Watching from Youtube

See also

The list below shows the Arduino Libraries I have developed to control DSP receivers.

• PU2CLR Si4735 Library for Arduino. This library was built based on “Si47XX PROGRAMMING GUIDE; AN332” and it has support to FM, AM and SSB modes (LW, MW and SW). It also can be used on all members of the SI47XX family respecting, of course, the features available for each IC version;

• PU2CLR SI4844 Arduino Library. This is an Arduino library for the SI4844, BROADCAST ANALOG TUNING DIGITAL DISPLAY AM/FM/SW RADIO RECEIVER, IC from Silicon Labs. It is available on Arduino IDE. This library is intended to provide an easier interface for controlling the SI4844.

• PU2CLR AKC695X Arduino Library. The AKC695X is a family of IC DSP receiver from AKC technology. The AKC6955 and AKC6959sx support AM and FM modes. On AM mode the AKC6955 and AKC6959sx work on LW, MW and SW. On FM mode they work from 64MHz to 222MHz.

• PU2CLR KT0915 Arduino Library. The KT0915 is a full band AM (LW, MW and SW) and FM DSP receiver that can provide you a easy way to build a high quality radio with low cost.

There is a Facebook group called Si47XX for Radio Experimenters where the purpose is exchanging experiences with projects based on Silicon Labs SI47XX IC family. You will be welcome to the group Si47XX for Radio Experimenters. You can also be a member of group.ioSI47XX for hobbyists

Your support is important

If you find some error or if you want suggest something else to this project, please, let me know. Thank you!

Schematics

A simple transmitter consists of an audio source and a carrier signal (generated by a crystal or DDS). The audio signal is mixed with the signal generated by the oscillator and then transmitted. The audio source can be a microphone or an audio output from any device like a smartphone, computer, CD player, FM receiver etc. The citcuits below show two very basic shortwave circuit. They provide very low power output and they can reach barely around 2 meters.

The schematic below is based on Stefan0719 and can be used with crystal oscillator. Use it if you want to work with a static frequency (8MHz, 12MHz, 13.56MHz etc).

If you intend to work with random frequencies between 3 and 30 MHz or other ranges, use the following circuit.

The sketch for the circuit above can be found here

Photos

MIT License

Copyright (c) 2019 Ricardo Lima Caratti

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE ARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

References

• Original Project Schematic

• Simple shortwave transmitter

• SIMPLEST SHORTWAVE TRANSMITTER CIRCUIT EVER

• DIY Simple Short Wave Transmitter With XTAL Oscillator Steady Frequency

• 13.56Mhz shortwave transmitter

• A DDS VFO for Codan Transceivers

• Replacing Crystal Oscillator with DDS

• A Technical Tutorialon Digital Signal Synthesis