Tagged: satellite

QO-100 Bullseye TCXO Ultra Stable LNB Now Available in our Store for $29.95 with Free Shipping

Back in March we posted about Othernet's release of their "Bullseye" TCXO ultra stable LNB for receiving QO-100 and other Ku-Band satellites. We have decided to now offer these for sale on our store as well.

They cost US$29.95 with free shipping to most countries. We are currently selling it over on our blog store and on our Aliexpress store. The Aliexpress store uses Aliexpress Standard Shipping which may be better for some countries like Poland, Ukraine, etc. As usual, please expect that there could be shipping delays at the moment due to the ongoing global pandemic. 

QO-100 / Es'hail-2 is a geostationary satellite at at 25.5°E (covering Africa, Europe, the Middle East, India, eastern Brazil and the west half of Russia/Asia) providing broadcasting services. However, as a bonus it has allowed amateur radio operators to use a spare transponder. Uplink is at 2.4 GHz and downlink is at 10.5 GHz. Most SDRs do not tune all the way up to 10.5 GHz, so an LNB (low noise block) is typically used, which contains the feed, an LNA, and a downconverter which converts the 10.5 GHz frequency into a much lower one that can be received by most SDRs.

In order to properly monitor signals on QO-100 an LNB with a Temperature Compensated Oscillator (TCXO) or other stabilization method is required. Most LNBs have non-stabilized crystals which will drift over time with temperature changes.  This means that the narrowband signals used on QO-100 can easily drift out of the receive band or cause distorted reception. It is possible to hand modify a standard Ku-band LNB by soldering on a replacement TCXO or hacking in connections to a GPSDO, but the Bullseye LNB is ready to use and cheap.

The Othernet TCXO Ultra Stable LNB for QO-100 and Ku-Band Satellites
The Othernet TCXO Ultra Stable LNB for QO-100 and Ku-Band Satellites

The official product details read:

The Bullseye LNB is the world's most precise and stable DTH/consumer Ku-band down converter. Even a VSAT LNBF costing hundreds of dollars more is no match for the performance of the Bullseye 10K LNB. Each unit is calibrated at the factory to within 1 kHz of absolute precision against a GPS-locked spectrum analyzer. Under outdoor conditions, the stability of the LNB is well within 10 kHz of offset. As a bonus feature, the  Bullseye 10K provides access to its internal 25 MHz TCXO through the secondary F-connector. This reference output can be used to directly monitor the performance of the TCXO over time. 

Features

  • Bullseye 10 kHz BE01
  • Universal single output LNB
  • Frequency stability within 10 kHz in normal outdoor environment
  • Phase locked loop with 2 PPM TCXO
  • Factory calibration within 1 kHz utilizing GPS-locked spectrum analyzers
  • Ultra high precision PLL employing proprietary frequency control system (patent pending)
  • Digitally controlled carrier offset with optional programmer
  • 25 MHz output reference available on secondary F-connector (red)

Specifications 

  • Input frequency: 10489 - 12750 MHz
  • LO frequency 9750/10600 MHz
  • LO frequency stability at 23C: +/- 10 kHz
  • LO frequency stability -20 - 60C: +/- 30 kHz
  • Gain: 50 - 66 dB
  • Output frequency: 739 - 1950 MHz (low band) and 1100 - 2150 (high band)
  • Return loss of 8 dB (739 - 1950 MHz) and 10 dB (1100 - 2150 MHz)
  • Noise figure: 0.5 dB

We note that an external bias tee power injector is required to power the LNB as it requires 11.5V - 14V to operate in vertical polarization and 16V - 19V to operate with horizontal polarization. The bias tee on the RTL-SDR Blog V3 outputs 4.5V so it is not suitable.

There has also been an excellent review by @F4DAV and a video review by Techminds which we show below.

Ultra Stable Bullseye LNB For QO-100 Es Hail2 10 kHz

Understanding PLLs and their Importance when Receiving/Transmitting on QO-100

Over on YouTube Andreas Speiss has uploaded a video that explains what the geostationary QO-100 satellite is, and explains about the parts needed to receive and transmit to it. In particular Andreas goes into depth explaining the low noise block (LNB), and the PLL inside it. A PLL or phase locked loop is a common design used in RF electronics as it allows us to increase the frequency of crystal oscillators.

This PLL explanation ties into the fact that most commercial LNBs available do not have a stable enough crystal oscillator to properly receive or transmit the narrowband amateur radio signals used on QO-100. A PLL can increase the frequency of a crystal, but it will also increase the frequency drift and jitter/phase noise of the crystal. He notes that in later videos he'll show how to modify the LNB to improve these factors. We note that a commercially available stable LNB is the Bullseye LNB which we have posted about previously.

QO-100 Satellite Receiving Technology. And Explanation of a PLL

Tutorial on Using xrit-rx to Receive Weather Images from Geostationary Satellite GK-2A

Over on his website VKSDR has recently released a tutorial about his Linux based xirt-rx software which allows RTL-SDR and other SDR owners receive weather images from the geostationary satellite known as GEO-KOMPSAT-2A (GK-2A). GK-2A is a Korean satellite, hence it is positioned over the Asia-Pacific region, covering Asia, Eastern Russia, Australia and New Zealand. 

To receive images from GK-2A you'll need an RTL-SDR, 2.4 GHz WiFi grid antenna and an L-band LNA. We have an earlier tutorial about receiving GK-2A and GOES geostationary L-band satellites that goes into more detail about the hardware required. 

VKSDR's xrit-rx software decodes the Low Rate Information Transmission (LRIT) signal from GK-2A which provides a 64kbps data stream and full disk images of the earth every 10 minutes. His tutorial explains the various image types that are transmitted, shows a few example images, and shows that some smooth animations can be created with the 144 images received over a day. The rest of the tutorial goes into the software setup, and explains the installation and configuration procedure.

We note that the latest version of xrit-rx now also comes with a nice web based dashboard that allows you to view the latest image, as well as the upcoming image schedule.

Full Disk Images Received from GK-2A via XRIT-RX
Full Disk Images Received from GK-2A via xrit-rxThe new web based dashboard for xrit-rx

The new web based dashboard for xrit-rx

A Few GOES Reception Tips and Info on Receiving EMWIN Data

Thank you to Carl Reinemann for writing in and sharing his website that contains a few tips that he's learned when setting up an RTL-SDR based receiver for GOES 16/17 weather satellite image reception.  As well as the tips, he's uploaded a nice set of images that show his setup, and several of the images he has received.

In addition, he's also noted how the default config files provided by goestools do not download EMWIN (Emergency Managers Weather Information Network) images. EMWIN images are not photos, but rather weather forecast and data visualizations that may be useful for people needing to predict or respond to weather. Over on his Github he's uploaded a modified version of goestools which has config files for EMWIN and other image products that might be of interest to some.

If you're interested, Carl Reinemann also has various bits of information about building APT/Meteor satellite RTL-SDR receivers on his main site too. Of interest in particular is his notes on creating wide area composites of NOAA APT images with WXtoIMG which we have posted about in the past.

Some EMWIN Images Received by Carl Reinmann's GOES receiver.
Examples of some EMWIN Images Received by Carl Reinemann's GOES receiver.

YouTube Series on Inmarsat Decoding with Scytale-C

Paul (microp11) is the programmer behind the Scytale-C Inmarsat decoder which has become very popular with RTL-SDR owners. With Scytale-C, and RTL-SDR and an appropriate L-band antenna and amplifier it is possible to receive STD-C NCS data from Inmarsat satellites. This is a public broadcast which contains information like search and rescue (SAR) and coast guard messages as well as news, weather, pirate activity and other incident reports. If you're interested, we have a tutorial available here which uses different software.

Paul has recently created a 6-part video series explaining Scytale-C and all it's features. As well as showing how to setup a Scytale-C decoder with the SDR# plugin in order to receive the STD-C text data via the UI, Paul's series goes into more depth showing how to review and inspect the raw data packets, how to monitor multiple Inmarsat channels at once using SDR# Spyservers and how to use the map feature for plotting coordinate and region data.

Inmarsat-C decoder Scytale-C Part II

Receiving SMOG-P and ATL-1 Nano Satellites with an RTL-SDR

Thank you to Zoltan Doczi (HA7DCD) for submitting his tutorial that shows how to receive signals from the SMOG-P and ATL-1 nano satellites which were launched via Rocket Lab back in late 2019.

SMOG-P is a Hungarian nano satellite developed by BME University. It's payload consists of an on board spectrum analyzer that is designed to measure electromagnetic pollution (electrosmog) from space, and to also monitor the DVB-T spectrum. It currently holds the title of the world's smallest satellite in operation.  ATL-1 is another Hungarian satellite this time developed by ATL Ltd. Its mission is to test a new thermal isolation material in space and to monitor the DVB-T spectrum.

To receive telemetry from these satellites you can use a Raspberry Pi, RTL-SDR, Yagi, and optionally an LNA and filter. In his post Zoltan shows how to install the SMOG-P decoder, and provides a script that automatically decodes, uploads packets to the BME University server, and archives old IQ files and packets.

We note that if you wish to receive these satellites, now is the time to do so as these nano satellites are in a very low orbit and only have an orbital lifespan of only 6-8 months total.

SMOG-P and ATL-1 Satellite Ground Station Receiver Setup
SMOG-P and ATL-1 Satellite Ground Station Receiver Setup

Starlink Doppler Reflections Caught with an RTL-SDR

Over on YouTube William IU2EFA has been uploading multiple short "meteor scatter" videos. This involves using an RTL-SDR to briefly receive distant radio stations via the RF signal reflecting off the ionized trail left by meteors entering the atmosphere. However, in a similar fashion satellites orbiting the earth can also reflect distant radio stations. 

In one of his latest videos William caught a train of Starlink satellites reflecting the signal from the Graves radar in France. To do this he uses a 10 element VHF Yagi, and an RTL-SDR running with HDSDR and SpectrumLab. In the video you can see and hear the change in frequency caused by the doppler shift.

Starlink is a SpaceX project aiming to bring ubiquitous satellite internet to the entire world. Currently 358 Starlink satellites are in orbit, and the end goal is to have 12000.

IU2EFA Starlink 2020-03-22 06:39:00 UTC

A Seminar on Setting up and Understanding a SatNOGS Satellite Ground Station

At the 2019 TAPR Digital Communications Conference (DCC), Corey Shields (KB9JHU) and Dan White (AD0CQ) presented a comprehensive guide on setting up your own SatNOGS satellite ground receiver station. The video of the presentation has just recently been uploaded to YouTube by Ham Radio 2.0.

SatNOGS is an open source project that aims to make it easy for volunteers to build and run satellite ground stations (typically based on RTL-SDR and Raspberry Pi hardware) that automatically receive RF satellite data, and automatically upload that data to the internet for public access. This is very useful for low budget cubesats launched by schools and small organizations who don't have the resources to run a worldwide satellite ground station network. Without global ground stations the majority of data and telemetry collected by the satellite could be lost as it would only pass over the owners ground station once or twice a day with limited time and bandwidth to downlink data. SatNOGS volunteers with distributed ground stations placed all over the world provide a free solution for this problem. 

Setting up a SatNOGS station and understanding the data coming down can be a pretty involved project, so Corey and Dan's 3.5 hr presentation gently guides us through the steps required. The guide focuses most on the software side, and does not include information about building their open source Yagi antenna rotator which can be used to receive satellites with lower power weak signals. Instead they focus on using a simpler fixed QFH antenna which is still capable of receiving data from a majority of satellites.

Learn to build and operate your own SatNOGS ground station. The Sunday Seminar is somewhat like the "anchor" topic of the entire weekend of the TAPR Digital Communications Conference. In 2019 we had the privilege of hearing from Corey, KB9JHU and Dan AD0CQ from the SatNOGS Team and they are going to give us, in detail, instructions for setting up a home satellite station.

(2:38) Intro
(7:46) Section 1: Satellite Building 101
(1:14:50) Section 2: Using SatNOGS
(2:19:55) Section 3: API and Contributing
(2:51:55) Section 4: RF Stack and Decoders

SatNOGS Ground Station Building Guide from TAPR DCC 2019