Low Cost Shielding Idea for Plastic RTL-SDRs

Generic RTL-SDRs that come with a plastic enclosure can be prone to picking up interference directly via the PCB itself. Higher end RTL-SDRs generally come with a metal enclosure.

Thanks to Alan R. for submitting a low cost idea he's come up with for shielding his plastic RTL-SDR dongles. Alan writes:

I’ve used this attached method with quite a bit of success for shielding the RTL dongle. It’s just a fizzy orange tube with two holes drilled at each end and some sticky metal insulating tape, which can be bought at any DIY store. Once the USB adapter and RTL dongle are inside they fit snuggly and any standard printer cable with reasonable length works well. Usually this allows for shorter coax connections which again helps keep the signal to noise level reasonable. I opted for a USB with a ferrite core at either end and I also added one to the coax - just because.

If you leave the antenna detached and tune in to any FM radio station you get a strong signal, and as soon as you put the RTL-SDR inside the insulated tube the signal stops. Needless to say if you plug the antenna in then the FM radio comes through with a strong signal. It certainly helps cut down a lot of FM broadcast noise (cheaply!)

I’m not using any band stop / band pass / pre amps and currently I’m receiving loud and clear satellite transmissions - NOAA / Meteor 2. I can even grab the telemetry from AO-73 Funcube with no problems. As the USB is shielded too and is away from the computer it also helps. Plugging the dongle directly into the computer tends to pick up a lot of unwanted noise.

The only thing to watch is it can get a little hot, so some common sense when using it (especially on a hot day). The other advantage is the weather proofing should you get caught in rain!

 

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The South Indian SDR User Group

Thank you to Balaji for writing in and sharing news about the growing South Indian SDR Users Group. The group have already held several virtual events where a variety of speakers have presented various topics on SDRs and related research. The recorded talks are available on their YouTube channel and include a variety of local Indian and international presenters.

About Us: The South Indian SDR User Group (SI-SDR-UG) was founded in January 2021, and is a community of people, from novices to experts, spanning industry, academia, and government, who are interested in the design and implementation of Software-Defined Radio (SDR) technology and systems. This includes such diverse areas such as RF, digital signal processing (DSP), wireless communications, operating systems, computer networking, software development and optimization, machine learning, and radio hardware. The mission of our community is to facilitate the exchange of ideas and enable greater collaboration within the SDR community in India. We host a regular technical workshops and gatherings, and we also run a dedicated Slack workspace for the community. We have a YouTube channel for recordings of past events, and a GitHub page for any relevant code. Our Twitter feed contains announcements about events and other news relevant to the community. We are not focused or tied to any one single software tool, hardware platform, commercial vendor, or specific technology. The SI-SDR-UG is non-profit, and the people on the organizing committee are all volunteers. We are based in Bangalore, but we invite people from all throughout India, as well as from outside India, to join our community. Please reach out to us on Slack or by email if you have any questions or comments. Thank you!

Website:https://www.softwaredefinedradio.in/
Slack:https://si-sdr-ug.slack.com/
YouTube:https://www.youtube.com/channel/UCy04XwXPMDVUucWYYvwg-Yg
Twitter:https://twitter.com/akashvani2021
Gmail: [email protected]

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Metal Case Upgrade for the SDRplay RSP1A Back in Stock!

Due to popular demand we have decided to manufacture one more batch of our SDRplay RSP1A metal enclosure upgrade kit. After numerous delays due to the Shanghai COVID lockdown, it is now in stock in our store and ready to ship out from our shipping warehouse in China. Amazon stock local to the USA will be arriving later around the end of July.

This is a premium aluminum metal upgrade enclosure for the SDRplay RSP1A. Helps block RF interference and protects the RSP inside the sturdy enclosure. We don't make batches of this enclosure often, and this batch could be the last, so if you are interested please order before stock runs out for good.

The kit includes 1x black aluminum metal enclosure with two labelled side panels, 1x black semi-hardshell carry case, 1x thermal pad to keep the RSP1A cool and mechanically stable inside the enclosure, 1x accessory set including enclosure screws, GND lug bolt set and 3M anti-slip rubber feet.

RSP1A Metal Case Upgrade
RSP1A Metal Case Upgrade
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TechMinds: Testing the ISM Packet Decoder Plugin for SDR Sharp

Over on the TechMinds YouTube channel Matt has uploaded a video demonstrating the use of the ISM Packet Decoder plugin for SDR# which was released a few months ago. The plugin authors website also contains more information about the installation and features of plugin.

The plugin makes use of the well known rtl_433 software behind the scenes, which is a command line based RTL-SDR compatible decoder for various wireless ISM band devices such as weather stations, car keys, tire pressure sensors, doorbells and various other remote controlled devices. The plugin GUI makes using and displaying data from rtl_433 much more convenient.

ISM Packet Decoder Plugin For SDR Sharp - RTL 433

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Probing a Cable Internet + TV Line with RTL-SDR USB

Thank you to Adam from Double A Labs for submitting his latest YouTube video where he uses his RTL-SDR to probe the coaxial cable that provides his broadband internet and cable TV. In the video Adam explains how hybrid fiber-coaxial internet and TV broadband networks (such as Comcast/Xfinity) work, and how the Specktrum software can be used with an RTL-SDR to explore the spectrum on these cables. Adam writes:

What I found was pretty interesting, including a few unmodulated analog TV carriers on the line producing a black screen on my TV. I also explain how coaxial broadband networks work (bi-directional amplifiers, upstream/downstream splits, etc.) and how internet service providers are upgrading them.

How Broadband Cable Networks (Xfinity etc.) Work and Probing One with a Spectrum Analyzer (RTL-SDR)

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NEWSDR 2022 to be held Virtually on June 3

The 12th New England Workshop on Software Defined Radio (NEWSDR 2022) is due to be held online again this year starting tomorrow at June 3 9AM - 6PM US Eastern time.

The 2022 New England Workshop on Software-Defined Radio (NEWSDR’22) is the twelfth installment of an annual workshop series organized by the Boston SDR User Group (SDR-Boston). Given the continued global health emergency of the COVID-19 pandemic, this year’s event will be safely hosted online in a virtual setting. Although this will be a virtual event, the NEWSDR 2022 organizers are committed to achieving the primary goal of this workshop by providing a forum that enables SDR enthusiasts to get together, collaborate, and introduce SDR concepts to those interested in furthering their knowledge of SDR capabilities and available resources. NEWSDR 2022 welcomes both experienced SDR enthusiasts as well as individuals who are interested in getting started with SDR.

There are some interesting talks, panels and posters that will be presented, a summary of which can be found on the NEWSDR 2022 page. These are mostly research level talks, that may be interesting to people who love cutting edge SDR and radio research topics.

The talks will be livestreamed on YouTube for anyone to watch live or at a later date. The livestream YouTube player is embedded below.

NEWSDR 2022 :: 12th New England Workshop on Software Defined Radio

If you're interested, presentations from last years NEWSDR 2021 can be viewed in the following YouTube video.

NEWSDR 2021 :: 11th New England Workshop on Software Defined Radio

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LimeSDR 2.0 Mini Now Crowdfunding, Standard LimeSDR Discontinued

Back in March we posted about the LimeSDR Mini 1.0 becoming end of life due to component shortages, and a slightly upgraded LimeSDR Mini 2.0 was being planned. The LimeSDR Mini 2.0 has just been released for preorder over on the CrowdSupply crowdfunding website with a price of US$399 + shipping. The first 1000 units are expected to be ready within 14-weeks, with subsequent batches out at 32-weeks.

The new pricing is at quite a premium over the original LimeSDR Mini which released in 2017 for US$139, and the standard LimeSDR which released in 2016 for US$249. However we of course must to take into account the extreme inflation of electronic parts pricing that has occurred over the past few years.

Lime Micro have also noted that the standard LimeSDR has also now been discontinued due to the same supply shortages. The standard LimeSDR had 2x2 RX/TX channels and was capable of a bandwidth of up to 61.44 MHz. In comparison, both versions of the LimeSDR Mini are a 1x1 channel product with 40 MHz of bandwidth.

The LimeSDR Mini 2.0 is almost identical to the LimeSDR Mini 1.0, both still making use of the LMS7002 RF transceiver as the main chip and using the same overall design. The only change is an upgrade to the FPGA, which replaces the Intel MAX 10 16k logic gate FPGA with a significantly more capable Lattice ECP5 44k logic gate FPGA.

Given the new pricing, people on the lookout for a new hacker/research/experimenter SDR in this price range might want to consider this brief comparison to find the best suited SDR for your needs:

  • LimeSDR Mini 2.0 - US$399
    1x1 channels, 40 MHz bandwidth, 10 MHz to 3.5 GHz, 12-bits.
     
  • HackRF One - US$330 (~$150 clones)
    1x1 channels (half-duplex), 20 MHz bandwidth, 1 MHz to 6 GHz, 8-bits.
     
  • PlutoSDR - US$229.18
    1x1 channels, 20 MHz bandwidth, 325 MHz to 3.8 GHz, 12-bits.
     
  • bladeRF 2.0 Micro xA4 - US$540
    2x2 channels, 61.44 MHz bandwidth, 47 MHz to 6 GHz. 12-bits.
The LimeSDR Mini 2.0
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Feeding ACARS Data to Airframes.io

Thank you to a contributor for submitting an article about Airframes.io, which is an ACARS/VDL2/HFDL/Satellite ACARS aggregation site. The article below it attributed to Kevin Elliott and was edited by Frank Vance. They would also like to attribute the large group or volunteers at Airframes.io.

One of the most popular hobbyist uses of SDR is receiving and decoding vehicle information data such as ADS-B for aircraft or AIS for marine traffic.  Some hobbyists have been banding together to exchange their mutual data streams to provide coverage over wide geographic areas.

One of the largest and most successful such projects in the aviation realm is ADS-B Exchange (https://www.adsbexchange.com/), where over 8,000 volunteer feeders provide ADS-B data to a global aviation map in real time.  

But modern air carriers have much more data to and from their aircraft than just the position information from ADS-B.  In the 1970s, ACARS was created to carry that traffic.  Today, ACARS is seen on its own frequencies on VHF, embedded in AVLC on the VDL2 VHF frequencies, on HF (shortwave) frequencies using the HFDL network of stations worldwide, and on satellite on both the Inmarsat (ACARS over AERO, or AoA) and the Iridium (called ACARS over Iridium, or AoI) systems.

Airframes.io (https://app.airframes.io/) is a project that has been under development for a while to aggregate ACARS data in the same way ADS-B Exchange is aggregating ADS-B data.  Under the capable leadership of Kevin Elliott (https://github.com/kevinelliott), software development has progressed to the point that new feeders are actively being sought to improve the global coverage and provide a broader base of data to improve the decoding.

With a wide variety of data sources, this is a collaboration project that is open to all levels of SDR hobbyists.  A simple RTL-SDR.COM unit attached to a Raspberry Pi with a smaller antenna works well with the VHF coverage.  Depending on one's interest level, an HFDL feeder may require multiple SDRs with much broader frequency range, capable of reception in the sub-30 MHz bands.  The L-band based Iridium AoI uses a small antenna as well, but requires a wide bandwidth SDR.  Finally, reception of the C-band Inmarsat (AoA) traffic may involve a moving dish antenna of at least 6 foot diameter to obtain usable signals.

What kind of data is seen in ACARS?   One can observe weather conditions aloft, messages to/from the carrier operations staff, information about the origin and destination of the flight, and technical data on the aircraft operation (not all of which can be decoded at this time.)  Additionally, the HFDL and satellite feeds offer location information out of sight of the traditional ADS-B coverage, such as over the oceans and polar regions.
 
The About page at Airframes.io (https://app.airframes.io/about) has plenty of good information to help anyone get started with feeding, including links to popular software packages useful for running different types of feeders.  Support is available on the #airframes-io channel (https://discord.gg/X2TgnFgsRW) on the ADSBExhange Discord server (https://discord.gg/aXt7KdycJk).
 
Additional information about setting up a receiver/feeder for HFDL, Inmarsat L-band, Inmarsat C-band, and Iridium L-band is available on The Bald Geek's GitHub page: https://thebaldgeek.github.io/Consider joining with the dozens of volunteers already feeding and contributing software updates to the Airframe.io project.
Airframes.io Map
Airframes.io ACARS Messages
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