Category: News

WWV and WWVH Special Messages to Broadcast!

Starting from Monday September 16th and continuing through to October 1st, both WWV and WWVH shortwave time signal transmission stations will broadcast a special message from the Department of Defense to mark the centennial of WWV. These messages will be heard on 2.5, 5, 10, and 15 MHz. In addition from September 28 to October 2 a special WWV event will occur:

The world’s oldest radio station, WWV, turns 100 years on October 1, 2019, and we are celebrating!

From September 28 through October 2, 2019, the Northern Colorado ARC and WWV ARC, along with help from RMHam, FCCW, and operators from across the country, are planning 24-hour operations of special event station WW0WWV on CW, SSB and digital modes. Operations will shift between HF bands following normal propagation changes and will include 160m and 6m meteor scatter. We will be operating right at the WWV site and face a challenging RF environment.

WWV is a [NIST] operated HF station based in Fort Collins, Colorado. It continuously broadcasts a continuous Universal Coordinated Time signal in addition to occasional voice announcements. It has been on the air since 1919 but began continuous broadcasts in 1945 from it’s final site in Fort Collins, Colorado. WWVH is a similar time signal, but based in Hawaii.

The WWV Transmit Building

The WWV time signal can be used to automatically set RF enabled clocks to the correct time. [Andreas Spiess] on YouTube recently uploaded a video where he emulates this signal in order to control clocks within his home. This is a great watch if you’d like to learn more about how these time signals work.

The time format itself is actually pretty simple and it’s possible to emulate with a number of devices from an Arduino to Raspberry Pi and of course Software Defined Radio.

Remote Controller for Clocks (IKEA and others, DCF77, WWVB, MSF, JJY)

SignalsEverywhere is Hosting An SDR Hack Chat

[Corrosive/SignalsEverywhere] will be hosting a Software-Defined Radio Hack Chat over on [Hackaday.io] on Wednesday September 18th at 12 PM PDT.

If you’re unfamiliar with Hackaday’s Hack Chat, these are chat sessions with individuals experienced in various fields in which anyone can join in and ask questions during the session. The Hackaday team has run these events with many guest hosts covering a plethora of interesting topics. This however, will be the first Hack Chat revolving around Software Defined Radio.

The hack chat will discuss many sub-hobbies of the SDR world from Amateur Radio and satellite operation to things like weather sonde tracking, monitoring and more.

If you have some SDR questions that have been burning you may want to hop on this session as it’s a one-day event, of course there is always our [Forums] where our community is happy to answer your questions as well.

KerberosSDR Batch 2 Ships Soon! Pricing will Rise on Monday

KerberosSDR Batch 2 will begin shipping very soon! Thank you to all who have supported this project so far. If you didn't already know KerberosSDR is our experimental 4x Coherent RTL-SDR product made in partnership with Othernet. With it, coherent applications like radio direction finding (RDF), passive radar and beam forming are possible.

We just wanted to note that this Monday the reduced preorder pricing of US$130 + shipping will end, and the price will rise to the retail price of $149.95 + shipping. So if you have been thinking about ordering a unit, now would be a good time. Ordering is currently possible through Indiegogo. On Monday we will change to our own store. EDIT: Now available to purchase on the Othernet Store.

For shipping, US orders will be sent domestically from Othernet's office in Chicago. They are still waiting on the US shipment to arrive, but it is expected to arrive by the end of next week. Once shipped locally you will receive a shipment notification.

For international orders, the packages are being labelled now, and should be going out early next week, or sooner.

KerberosSDR Inside and Outside the Enclosure
KerberosSDR Inside and Outside the Enclosure

Future Updates to KerberosSDR

With the profits raised from KerberosSDR sales we are looking to continue funding development on the open source server software and visualization software being created (as well as applying updates ourselves). In future updates we will be looking at features such as:

  • Streamlining the sample and phase sync calibration process.
  • Experimenting with software notch filters for calibration (may reduce the need to disconnect the antennas during calibration).
  • Reworking the buffering code for improved sample ingestion performance and increased averaging.
  • Direction finding and passive radar algorithm improvements.
  • Creating a networked web application for combining data from two or more physically distributed KerberosSDRs over the internet for immediate TX localization.
  • Updates and bug fixes for the Android mobile direction finding app for use in vehicles.
  • Improving passive radar to be able to use all four RX ports for surveillance so that larger areas can be covered.
  • Plotting passive radar pings on a map.
  • Beginning experimentation with beam forming.
  • In the farther future we hope to eventually have even more clever software that can do things like locate multiple signals in the bandwidth at once, automatically plot them on a map, and track them via their unique RF fingerprint, or other identifiers.
  • Future hardware updates may see more streamlined calibration and smaller sizes.
KerberosSDR Android App for Direction Finding
KerberosSDR Android App for Direction Finding

Reviews of the NanoVNA: An Ultra Low Cost $50 Vector Network Analyzer

A vector network analyzer (VNA) is an instrument that can be used to measure antenna or coax parameters such as SWR, impedance and loss. It can also be used to characterize and tune filters. It is a very useful tool to have if you are building and tuning home made antennas, filters or other RF circuits. For example if you are building a QFH or ADS-B antenna to use with an RTL-SDR, a VNA can help ensure that your antenna is properly tuned to the correct frequency. Compared to a standard SWR or network analyzer a VNA supplies you with phase information as well.

Until just recently, VNA's have cost roughly US$500 for a decent USB PC based unit like the miniVNA or PocketVNA, and have set people back thousands to tens of thousands of dollars for bench top units.

However, the cost of owning a VNA has now been reduced to only US$50 thanks to the NanoVNA. The open source NanoVNA project by @edy555 and ttrftech has been around since 2016, but only recently have Chinese sellers begun mass producing the unit and selling them on sites like Aliexpress, eBay and now Amazon. We note that it seems that there are some sellers selling them without shielding, so it might be worth double checking the listing to see if they mention that. All the listings we've seen seem to come with simple calibration kits as well.

The NanoVNA: A $50 Vector Network Analyzer
The NanoVNA: A $50 Vector Network Analyzer

The NanoVNA is a small credit card sized VNA. It has a built in LCD screen that can be used to display graphs directly, or it can also be connected to a PC and the graphs viewed via the NanoVNA Windows software. When purchasing you can opt to include a small battery for portable operation for a few dollars extra. The frequency range is from 50 kHz to 900 MHz, although you should note that above 300 MHz dynamic range performance is reduced.

Over on YouTube several hams and radio enthusiasts have recently uploaded videos demonstrating and reviewing the NanoVNA. The overall consensus is that the unit is accurate and works well. For additional support there is forum available at Groups.IO.

Below YouTube user IMSAI Guy reviews the NanoVNA. Check out IMSAI Guy's other videos too as he has several where he tests the NanoVNA on difference filters and antennas, and checks the accuracy.

#350 NanoVNA Vector Network analyzer 900MHz VNA for $50

Below is YouTube user joe smith's review. He also has two other NanoVNA videos on his channel where he shows how to use the NanoVNA to measure antenna impedance, and how to use the NanoVNA to create SPICE models for simulation.

The NanoVNA, a beginners guide to the Vector Network Analyzer

Finally YouTube user Oli gives another overview. Please note that the following video is in Polish, but YouTube captions can be set to English.

NanoVNA - omówienie, kalibracja, pomiar anteny i filtra [english subtitles]

We've also seen several recent text reviews:

NanoVNA - A short review. In this review nuclearrambo shows off the calibration kit, and shows a practical measurements of a directional coupler and 137 MHz QFH antenna.

NanoVNA compared with a Keysight fieldfox N9952A. Here nuclearrambo provides a comparison between the $50 NanoVNA and the $40,000+ Keysight FieldFox N9962A.

The NanoVNA, a real VNA at less than 48 €!. A review written in French, but Google Translate can be used. In this review David Alloza compares the NanoVNA against an Agilent E5062A benchtop VNA, and results look comparable.

Talks from GNU Radio Days 2019

GNU Radio Days 2019 was a workshop held back in June. Within the last week recordings of the talks have been uploaded to YouTube by the Software Defined Radio Academy channel. The talks cover a wide range of cutting edge SDR research topics and projects. Many of the presenters have also made use of RTL-SDR dongles, as well as other higher end SDRs in their research.

All the talks are combined into two 3 hour long videos from the morning and day sessions from day one. Day two also has two videos that consist of recordings from the tutorial sessions which make use of the PlutoSDR. Finally there is also the keynote speech from Marcus Müller where he dives into the internal workings of GNU Radio.

Below we list the talks with timestamps for the YouTube video. Short text abstracts for each of the talks can also be found in the conference book. We note that not all the abstracts appear to have been presented in the videos, so it may be worth checking out the book for missed talks about passive radar, a 60 GHz link, embedded GNU Radio on a PlutoSDR, an SDR 802.11 infrared transmission system, PHY-MAC layer prototyping in dense IoT networks and hacking the DSMx Drone RC protocol.

Continue reading →

SDRTrunk 0.4.0 Alpha 9 Updates Highlighted

You may recall that a few years ago we released a tutorial on how to set up and use [SDRTrunk]. Fast forward a few years and the software has seen numerous changes. This application was designed primarily for tracking trunking radio systems but also has the ability to decode things like MDC-1200, LoJack and more.

The software is compatible with many Software Defined Radios such as our RTL-SDR v3, HackRF and the Airspy. Some of the newer improvements include a bundled copy of java so that an installation of java is not required on the host computer, as well as decoding improvements for P25 among other digital voice modes. You can find a full list of improvements along with the latest release on [GitHub]

The biggest feature many have been waiting for is the ability to import talk groups for their radio system into the application from radio reference. While this has not yet been implemented, user [Twilliamson3] has created a [web application] that will convert table data from radio reference into a format that is supported by SDRTrunk.

SDRTrunk Screenshot
SDRTrunk Screenshot

GNU Radio 3.8.0.0 Released – First Minor Release Version in Six Years

GNU Radio is an open source digital signal processing (DSP) toolkit which is often used to implement decoders, demodulators and various other SDR algorithms. Several SDR programs are based on GNU Radio code, and it is responsible for a lot of DSP development and knowledge within the SDR and radio community. It is compatible with almost all SDR devices, including the RTL-SDR.

Recently GNU Radio has been updated to version 3.8.0.0. The release is classed as the first "minor" release version in six years, as they are going from version 3.7 to 3.8. That doesn't mean there have been no changes for six years, it just means that over the last six years all releases have remained within the 3.7 version and they have mostly been bug fixes rather than larger changes like added features. Behind the scenes over the last six years developers have been working on these larger changes, and now is the time that they have been officially released.

Marcus Müller from GNU Radio writes:

Witness me!

Tonight, we release GNU Radio 3.8.0.0.

It’s the first minor release version since more than six years, not without pride this community stands to face the brightest future SDR on general purpose hardware ever had.

Since we’ve not been documenting changes in the shape of a Changelog for the whole of the development that happened since GNU Radio 3.7.0, I’m afraid that these release notes will be more of a GLTL;DR (git log too long; didn’t read) than a detailed account of what has changed.

What has not changed is the fact that GNU Radio is centered around a very simple truth:

Let the developers hack on DSP. Software interfaces are for humans, not the other way around.

And so, compared to the later 3.7 releases, nothing has fundamentally modified the way one develops signal processing systems with GNU Radio: You write blocks, and you combine blocks to be part of a larger signal processing flow graph.

With that as a success story, we of course have faced quite a bit of change in the systems we use to develop and in the people that develop GNU Radio. This has lead to several changes that weren’t compatible with 3.7.

The changelog is too long to quote here, but as a summary they have fixed bugs, updated dependencies to newer versions, enabled C++ code generation, changed XML to YAML, moved from QT4 to QT5 and removed a few stale projects. Some of these changes could break compatibility with older GNU Radio tutorials and programs. It also seems that unfortunately due to a lack of updates, support for the Funcube Dongle has been removed.

SignalsEverywhere 10,000 Subscriber Interactive Live Stream with Giveaways on August 10 12PM EST

The SignalsEverywhere YouTube channel is quickly growing in size, and has recently passed the 10,000 subscriber milestone. If you weren't aware, Corrosive (aka KR0SIV aka Harold) who runs the channel has been consistently putting out high quality videos related to the software defined radio hobby. He's also started a podcast which also covers some interesting topics.

Some Recent SignalsEverywhere YouTube Videos
Some Recent SignalsEverywhere YouTube Videos

To celebrate hitting the 10,000 subscriber mark, Harold is planning an interactive 6 hour+ YouTube live stream which will begin on Saturday August 10 12PM EST time (11 hours from the time of this post). If you want to be automatically reminded of the stream, go to the live stream place holder, and click on set reminder.

The stream will be interactive as he is planning on setting up several SpyServer's that will be running across the HF, VHF, UHF and L-Bands. This will allow the audience to use SDR# to connect to his SDRs that are being used on the stream, allowing people to follow along with what Harold is doing on the stream, and ask questions about what they are seeing.

We're also helping to sponsor his stream and will be donating 5x RTL-SDR dongle + antenna kits, 5x RTL-SDR dongles, 1x Radarbox bundle, as well as one KerberosSDR to any giveaways that he plans on doing throughout the stream.

We really like Harolds work on YouTube, and if you are a fan of the content on our RTL-SDR.COM blog, then you really should be subscribed to his channel too.

Interactive SDR Live Stream | 10K Subscriber Celebration and Giveaway!