Dish antenna for the amateur radioastronomy

In the previous article I discribe low noise amplifier for the 21cm band. Today I wanna show you construction of the dish antenna where this amplifier can be used.

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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. Typically input stage is some kind of the amplifier with extremely low noise and high gain due to weakness of the space signals.
In this article I want to describe simple and cheap amplifier for the first stage of the receiver.

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Listening to aircrafts and receiving images from the satellites

In the previous article we discussed how to calculate and build simple Yagi-Uda antenna.
Now it’s time to play with this antenna and receive some interesting signals.

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144 MHz Yagi-Uda antenna

Yagi–Uda antenna is a directional and pretty effective antenna consisting of multiple parallel elements in a line, usually half-wave dipoles made of metal rods.

Best-known use of this type of antenna is as rooftop terrestrial television antennas, but it is also used for point-to-point fixed communication links and for long distance shortwave communication by shortwave broadcasting stations and radio amateurs.

In this article i will show how to build a simple 5 element antenna for 144 MHz band from widely available parts, and how to get some fun with it.

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