Electronics, Radio & antennas

1PPS distribution circuit

1PPS is a great way to synchronize multiple devices and measure time intervals. A typical source of the 1PPS is a GPS receiver. This clock is disciplined by GPS atomic clock and has a reasonable precision. GPS receiver 1PPS output should have enough loading capability, but it’s a good idea to use a buffer. Especially when voltage level translation is…

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Electronics, Linux system development, Radio & antennas, Radioastronomy, Software

Satellite LNB controller with GUI interface

Satellite LNB are quite cheap and easy to get devices. There are different models for different bands (C, Ku, and Ka) with different characteristics like SNR, noise figure, etc. Typically those devices are used with TV Set-top boxes. More interesting is that LNB can be easily connected to an SDR receiver. LNB is a simple frequency down-converter with an output…

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Electronics, Radio & antennas

Cheap single-component RF filters

Low, Band, and High – pass filters are major components when working with RF. Depending on the application, filters can reduce output noise and unwanted signals or limit a transmit signal to a pre-specified frequency band to prevent interference with other signals. Here I want to describe how to build simple and cheap single-component (ceramic) filters for your DIY projects.

Astro tools, Electronics, Radio & antennas, Radioastronomy

Low noise and low cost amplifier for radio astronomy, 21 cm band

21 cm band, also known as the Hydrogen line, is one of the important bands in radio astronomy. Please read this Wikipedia article if you not familiar with the Hydrogen line. Nowadays, even radio amateurs can observe this signal from outer space, thanks to modern hardware. One of the most important parts of any receiver is the antenna and input…

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