Transmitting WSPR Reports

The WSPR (Weak Signal Propagation Reporter, pronounced ‘whisper’) radio transmission technique was developed to enable considerable distances to be spanned using low power and minimum bandwidth. This article shows how you too can transmit WSPR reports using the Elektor SDR Shield and free software.

The final instalment of the short series on opamp basics explores some of the more unusual features of operational amplifiers. Another topic is opamps with power outputs.

In many applications it is essential to use an opamp with extremely high impedance inputs. In these cases a standard bipolar device will not do the job, and instead we must use an opamp with FET (field-effect transistor) inputs.

Too many electronics enthusiasts harbour a certain reluctance to enter the world of microcontrollers and programming. It really is not so difficult, as we will show by introducing four low-cost boards. You will see the setup and how some simple demo programs can be run so that early success is guaranteed. To get things going we gave a low-cost Arduino board to Burkhard Kainka who is one of our long-time contributors to Elektor and a specialist in many fields of electronics. His son Fabian will be giving us the lowdown on the NodeMCU board — a platform designed especially for IoT applications.

Operational amplifiers are ubiquitous in electronics, being used in a wide range of applications in all sorts of configurations. There are numerous device families and types available, each with their own strengths and weaknesses. So here we will take a closer look at the details.

This concluding part of our series on the Elektor SDR Shield 2.0 [1] is also the start of a new beginning. This automatically tunable receiver with two controllable VFO outputs opens up countless new opportunities, several of which are discussed in the article.

The SDR Shield 2.0 introduced in ElektorLabs Magazine edition 4/2018 offers a broad range of opportunities, not only for broadcast reception but also for amateur radio applications. You can hear SSB signals, also listen to CW and numerous digital signals for which you will need additional software to be able to decode them.

Smartphones and tablets are increasingly displacing conventional PCs. Even in kids’ bedrooms, mobile devices are now standard equipment. However, can they also be used as platforms for electronic design, prototyping and development projects?

About two years have passed since the launch of the Elektor SDR Shield for creating a shortwave SDR using the Arduino [1]. Plentiful positive feedback and countless experiments have aroused the desire to provide greater connectivity onboard. SDR Shield 2.0 is now the basis for far more than simply a receiver. Applications range from a signal generator through shortwave transmitters all the way to forming a complete shortwave transceiver.First steps with G8JCFSDR As not all readers will be familiar with the original SDR Shield, we ought to describe its beginnings here briefly.

If you basically do electronics as a pastime, you are usually under the radar of the authorities. Only really big mistakes can have painful consequences. If your product unintentionally radiates a considerable amount of RF energy, you can expect to receive unpleasant questions. And if you build something that hurts someone, you can face criminal charges.