Who’s following me on Twitter probably knows some details. I believe this is my most expected article. Last year I came up with the idea to build a wideband SDR. It’s fun to monitor a wider spectrum and some signals. Sure, USRP is cool but too expensive for amateur usage. I had a few HackRF boards, so I ordered more…
Category: Radio & antennas
Housing for the 1PPS/Square clock 8 channel distribution amplifier
While experimenting with my clock distribution amplifier, I found that this board creates a lot of interference to my HackRF receivers. Plus, it’s not very convenient to work with a bare board. I decided to build metal housing for this board. This is just a little note about its construction and some nuances.
1PPS/Square clock 8 channel distribution amplifier
This is a “production” version of my 1PPS distribution prototype. Now, this device supports 1PPS and Square clock signal distribution for 8 consumers. The new device is designed with lower delays and flexible configuration in mind. You can find the schematic and all required production files below.
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…
Small satellite dish with rotator
Receiving and analyzing radio signals is fun. Receiving satellite signal is even better. A few years ago, I had a nice 3m satellite dish with a hydrogen line receiver. Now I have only a small balcony with limited antennas placement ability. I decided to build a custom 40 cm dish with a servo-based rotator. Sure, it’s impossible to receive weak…
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…
Mysterious Flat satellite antenna from China
A few months ago, I found a quite unusual satellite antenna on the well-known Chinese portal. The antenna was relatively small, completely flat, and declared as a Ku-band satellite TV antenna. I was really wondered what’s inside and how it works so I decided to buy one sample.
Reworking linear polarization satellite LNB into a circular polarized
In this article, I want to discuss different types of satellite LNB, polarization, and depolarization of waves. Also, I’ll show how to rework the LNB. Also, we will discuss a theory to figure out why this rework is working. The primary topic here is Ku-band LNB, but all this also works for the Ka-band and C-band.
Combining two HackRF SDR to see more
HackRF One is a popular SDR transceiver and a really nice piece of hardware. For a reasonable price, you can get fully open hardware to monitor radio signals in a wide range (20MHz – 6GHz, but really up to 7GHz). Boards support external clocking and can be easily customized. I believe there is only one concern about this board is…
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.