Electronics, Radio & antennas

Cheap single-component RF filters.

Low, Band and High – pass filters are one of the major components when working with RF. Depending on the application, filters can reduse out noise and unwanted signals, or to limit a transmit signal to a pre-specified frequency band in order to prevent interfering with other signals around. Here I want to describe how to build simple and cheap…

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Electronics, Networking, Software

RS-485 practice and theory

Just built two RS-485 adapters (version 2) and decided to write little note about  RS-485 bus (and differential line) theory plus perform some testing of the devices. This material mostly interesting for newbies. In the end of this article you can find a funny way to test this devices đŸ™‚

Electronics

Isolated USB to RS485 adapter version 2

This is a second version of the usb to RS485 adapter. Please read this article about the first version. New device is built with ISO3082 and requires less components. Also this device can provide more reliability in some situations.

Astro tools, Electronics, Radio & antennas

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

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

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Allsky camera, Astro tools, Electronics, Software

Autonomous Allsky camera with Raspberry PI. Part 3: shooting night sky in FITS using QHY5-IIM camera

This is a third part of the Allsky cycle. Please read previous articles to get complete information about this project: Part 1. Autonomous Allsky camera with Raspberry PI: overview. Part 2. Autonomous Allsky camera with Raspberry PI: powering and lightning protection This time I will show my utility and script for shooting night sky and processing of the images.

Electronics

Isolated USB to RS485 adapter

RS485 is a standard for use in serial communications systems. Electrical signaling is balanced, and multipoint systems are supported. This communication standard is used in a wide range of computer and automation systems. RS-485 is used as the physical layer underlying many standard and proprietary automation protocols used to implement Industrial Control Systems, including the most common versions of Modbus…

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Allsky camera, Astro tools, Electronics

Autonomous Allsky camera with Raspberry PI. Part 1: overview.

Allsky (or weather) camera is one of the most important part of the modern observatory. It’s very important to monitor sky condition during night observations, especially when observatory is remote controlled or should be fully automatic. Different vendors provides different solution. But all they are share the same problems: very high prices, lack of autonomy (PC is required) and lack…

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