ThumbNet Special RTL-SDR For Sale: TCXO, Type F Connector, R820T2

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Only $39.95 USD plus shipping ($7.4 USA incl. taxes, $10 international). Click add to cart to begin ordering. Shipping will be added at checkout.

***SORRY ALL UNITS SOLD OUT***

If you missed out stay tuned, as we will have something similar for sale by the end of August. Sign up to our mailing list to be notified when the new units are for sale.

We have very limited quantities of surplus ThumbNet RTL-SDR dongles to sell. These RTL-SDR’s are significantly improved over the standard model, yet sell for a lower cost compared to other similar offerings. They have the following features:

  • A 1 PPM Temperature Compensated Oscillator (TCXO). Near perfect frequency offset and very low drift due to temperature.
  • Type-F antenna connector. Much sturdier and more common than the MCX connector used on most dongles.
  • Uses the R820T2 tuner chip. Improved sensitivity over the standard R820T.

In addition to receiving a high quality TCXO RTL-SDR for a price lower than any similar offering on the market at the moment, you’ll feel good knowing that you are also supporting an educational organisation which is helping to engage students in technology and the sciences.

Why are we selling these?

The ThumbNet educational project required a high quality custom RTL-SDR dongle to give out to students. In order to produce a custom model like this they had to order very large quantities from the factory – about double what they actually needed. We are simply helping them sell off the unneeded surplus and we expect stock to last until about mid year. Note that apart from helping them provide a cart which links to their PayPal account, RTL-SDR.com is not affiliated with the ThumbNet project apart from a very small commission that will directly support this site.

Shipping

All orders will be shipped by ThumbNet who are based in the USA. Orders will be shipped out in a padded envelope within 2 business days. 

Domestic orders should be received within 7 business days from time of order, usually faster. For international orders delivery times will vary but they should arrive within 2-4 weeks (usually less, but possibly longer for some remote countries) depending on any customs or postage delays in your country. If you don’t receive your order within these time frames please contact info_AT_thumbsat.com.

Warranty

ThumbSat is offering six months warranty against manufacturing defects on these dongles.

If you have any queries about faults or problems with the ThumbNet receivers you can contact info_AT_thumbsat.com.

Larger Orders

If you wish to order over 25 units please email info_AT_thumbsat.com and ask for a quote.

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ThumbNet – A Low Cost Satellite Groundstation Network using modified RTL-SDRs

The ThumbNet project is a project that is aiming to provide low cost satellite receivers to students and any other interested communities in order to promote worldwide education in science, technology and engineering.

In addition to ThumbNet, there is also the ThumbSat project which hopes to launch it’s own satellites sometime next year. However, at the moment the focus is on ThumbNet where the team are currently building their ground station network by supplying customized RTL-SDR dongles to schools and interested communities all around the world for free.

Once the satellites are launched the receive stations will be used to download data from the ThumbSat satellites, creating a large network of receivers. To raise the incentive for participation, in the future they also hope to provide a small amount of money to each actively participating school or organisation. They write that the RTL-SDR’s could also be used for receiving other educational signals such as communications from the ISS. More information about the project can be found on their website www.thumbsat.com, and in this white paper (pdf).

As generic RTL-SDR dongles were not up to their specifications they decided to develop their own. Their RTL-SDR receivers are custom made to have a 1 PPM accuracy Temperature Controlled Oscillator (TCXO), a R820T2 tuner chip and a F-Type connector. The Type-F connector was chosen as they found that it was the most commonly found connector around the world and would be the easiest for students in remote areas to have access to.

If you are interested in getting one of these dongles and you meet their criteria (school or similar), you can either ask to participate in the ThumbNet program for free, or alternatively if you just want a dongle for your own use you can buy one through us. We have decided to help with the ThumbSat project by helping them advertise and sell off some of their surplus units through our blog.

In their official blurb ThumbSat writes:

Scoutek LTD, in the United Kingdom and ThumbSat Inc, in the United States are proud to have partnered together to provide an opportunity for schools and educational groups around the globe to promote radio science, technology, engineering and mathematics to their students and attempt to influence the next generation of scientists and engineers.  By donating small radio kits to each school or educational group, the project has already begun making a positive change in the lives of hundreds of students.

ThumbSat has been working with schools and educational groups around the globe and to date, more than 20 groups have committed to volunteering where students and staff members will operate the satellite monitoring stations as part of their science courses!  As a few examples, stations are being operated in diverse areas the Cook Islands, Christmas Island, Singapore, Ecuador, Tanzania and Botswana. One individual in Micronesia was operating the station by himself at 12 years old!

ThumbNet is open to anyone who is interested in participating and has a desire to setup and operate a small ground based radio listening station. No permits or licenses are required, since there is no transmission of any sort and no permanently installed antenna systems.

ThumbSat and Scoutek encourage education for everyone and is looking for anyone young, old, educated or uneducated, individuals or groups to participate.

Questions can be directed to [email protected], or by visiting the company websites: www.thumbsat.com or www.scoutek.com .

ThumbNet SDR Dongles
ThumbNet SDR Dongles with Wade, one of the people behind the project.

Homemade Upconverter for the RTL-SDR Running on a Cellphone Battery

Over on YouTube user ek6rsc has uploaded a video showing his home made upconverter for the RTL-SDR. His upconverter uses a diode mixer design with a low pass filter and 40 MHz oscillator which he obtained from a USB-WIFI adapter. Usually an upconverter is powered by a power plug or USB cable, but ek6rsc has powered his with a 3.7V 860ma cellphone battery. He writes that the battery lasts a long time and helps avoid interference caused by power adapters and the PC. Ek6rsc has also uploaded a second video showing the upconverter in action.

Up-converter for RTL-SDR 40MHZ Lo. & cellphone battery

How work Up-converter for RTL-SDR 40MHZ Lo. & cellphone battery

New ADS-B Mapping and Decoder App for Android from FlightAware

Flightaware.com is a web based online radar service for aircraft. The plane position data is obtained from contributors running ADS-B decoding hardware, such as a special ADS-B receiver box or simply an RTL-SDR dongle.

To increase the number of contributors, the team at FlightAware have released a new RTL-SDR compatible ADS-B decoder app for Android devices. The App is totally free and is also ad free. It can be downloaded from the Google Play store at https://play.google.com/store/apps/details?id=com.flightaware.android.flightfeeder. The intention of the app is to target users who may have an old Android device lying around, which can be put to good use in contributing data to FlightAware. More information about running the app can be found on their webpage.

When sharing data with FlightAware you are then eligible for a free enterprise account valued at $89.95 a month which allows you to access several advanced flight tracking features.

To use the app you’ll need an Android device, a USB OTG cable (ideally with external power port) and an RTL-SDR dongle. The USB OTG cable should ideally have an external power port and be powered from the mains with a power adapter as the battery can drain fast.

FlightAware ADS-B App
FlightAware ADS-B App

New ADS-B Decoder for the Airspy Released

Youssef, the main programmer of SDR# and creator of the Airspy software defined radio has just released a beta version of an ADS-B decoder for the Airspy. The software is called “ADSB Spy” and is similar in operation to ADSB# which is used with the RTL-SDR dongle. The increased sensitivity and lower noise floor of the Airspy should help ADS-B enthusiasts get longer ranges and more aircraft on their screen.

The beta version of ADSB Spy can be downloaded at http://www.airspy.com/downloads/adsbspy.zip.

ADSB Spy - An ADS-B decoder for the Airspy
ADSB Spy – An ADS-B decoder for the Airspy

New Web Based RTL-SDR Remote Control Software: YouSDR

Recently Kristian, a reader of our blog wrote in to let us know about a new software project he found that allows you to use your RTL-SDR remotely through a web interface. The web interface runs on Linux and uses mysql and the Apache server to work. Currently it can be used to access options for rtl_fm, rtl_tcp, dump1090 and can also be used to create an icecast audio stream.

The software can be downloaded from its Git at https://github.com/sixuniform/yousdr. The instructions on the GitHub page show how to set it up on a Raspberry Pi running Raspbian, but the instructions should also be valid for other Linux distributions. As the software is new the authors are welcoming any improvements and feedback.

Some similar web based RTL-SDR remote control software that you may be interested in includes WebRadio and rtl_fm_python.

The YouSDR web interface.
The YouSDR web interface.

Spyverter Sneak Preview

The Spyverter is being developed by the creators of the Airspy software defined radio to be a high performance upconverter. It is designed for use with the Airspy, but may also be compatible with other SDR devices too.

Compared to most other upconverters which use a diode ring mixer architecture, the Spyverter uses a different, as of yet undisclosed architecture. The main claimed advantages over other upconverters will be it’s low loss and high IIP3 performance, which means that the Spyverter will not saturate in the presence of strong signals as easily as other upconverters.

Recently a photo of a Spyverter alpha board was released, indicating that the Spyverter is getting close to release.

The Spyverter Alpha
The Spyverter Alpha

Also, a few months ago W9RAN posted a YouTube video about a prototype HF upconverter for the Airspy and we believe he was using an early version of the Spyverter.

Airspy HF Converter Sneak Peek by W9RAN

Direct Sampling 14 MHz Low Pass Filter and Galvanic Isolator for the RTL-SDR now for sale in Japan

Previously we posted about Japanese RTL-SDR experimenter Nobu and his work in prototyping a new 14 MHz low pass filter and galvanic isolator for use with the RTL-SDR. The low pass filter improves reception when using the RTL-SDR in direct sampling mode by reducing out of band interference and the galvanic isolator (isolation transformer) reduces computer and other noise when using the RTL-SDR with an upconverter.

The products can be bought from the Japanese Amazon store [Galvanic Isolator] [Low Pass Filter], however to purchase from outside of Japan you will need to use a third party shopping service available at http://agent.jzool.com/.

If you are interested in Nobu’s products, he also has direct sampling modified RTL-SDR dongles and dongles with 10 ppm crystals available, as well as his own upconverter for sale in Japan.

Galvanic Isolator
Galvanic Isolator
14 MHz Low Pass Filter
14 MHz Low Pass Filter