In his latest video, Matt from the TechMinds YouTube channel tests out an LHCP L-band helix feed designed for receiving Inmarsat satellites. Matt pairs the feed with an 85cm satellite dish, an L-band LNA, and an Airspy Mini.
The L-band helix feed comes from a small German engineering company called nolle.engineering. The feed is priced at 94.70 Euros (incl. VAT) (~$102 USD), plus shipping costs. It is a passive antenna so it needs to be combined with an LNA to be usable with a typical SDR.
In the video Matt shows that the reception with the LHCP helix + dish setup is better than expected. He also compares it to a previous test he did with a longer RHCP helix antenna also produced by nolle.engineering. The RHCP antenna is used to be used without a dish, however, as expected the SNR is less than the dish + small LHCP feed setup. Matt then shows some Inmarsat signals being decoded including STD-C and Aero voice.
Paolo Romani (IZ1MLL) has recently released the 2024 version of his SDR# Big Book. The book is available for download on the Airspy downloads page, just scroll down to the title "SDR# Big Book" and choose your language. (At the time of this post only English and Italian are available in the 2024 edition, but multiple languages are available for the older guides).
Paolo writes that the book has been updated for the latest SDR# v1920 version, and now the editions will be labelled by date, instead of version number. He also writes that page 25 of the big book now includes information about the differences between RTL-SDR Blog V3 and V4 dongles.
Airspy is currently holding their annual summer sale which gives 15% off their line of products until June 30 2024. The sale brings the price of the popular Airspy receiver products down to the following in US dollars (note that actual pricing may vary across local resellers):
Airspy R2: $169.00 $143.65
Airspy Mini: $99.00 $84.15
Airspy HF+ Discovery: $169.00 $143.65
Airspy SpyVerter R2: $49.00 $41.65
YouLoop Antenna: $39.95 $33.95
The sale is active at all participating resellers, which includes our own store where we have the YouLoop on sale for US$33.95 including free shipping to most countries in the world.
Over on Twitter/X @lamdbaprog, creator of Airspy products and the SDRSharp software has teased his next upcoming software-defined radio hardware called the "Airspy HF+ Ranger". The Airspy HF+ Ranger prototype was also seen at the Dayton Hamvention through their local Airspy.us reseller.
The specifications appear to be very impressive, with a wide frequency range of 0.5 kHz to 1750 MHz and excellent sensitivity, linearity, and dynamic range figures. The Ranger is based on the same main RF chips used in the HF+ Discovery, so it will retain the relatively small maximum bandwidth capability of 710 kHz. However, for many use-cases this small bandwidth is more than sufficient.
Currently, there is no word on a release date or pricing but given the prototype status, it must be close. We expect this to be priced higher than the Airspy HF+ Discovery which sells for US$169.
Update: A page for the Airspy Ranger is now on the Airspy website. It shows a block diagram and further details. RTL-SDR.COM reader Ladislav has also sent us a PDF with the specs and a Dynamic Performance graph.
Over on Twitter/X, patrons of the Dayton Hamvention event have posted a few pictures of the display.
Over on his YouTube channel, Rob VK8FOES has started a new video series about Iridium Satellite Decoding. Iridium is a constellation of low-earth orbiting satellites that provide voice and data services. Iridium was first decoded with low cost hardware by security researchers back in 2016 as mentioned in this previous post. Being unencrypted it is possible to intercept private text and voice communications.
Rob's video is part of a series, and so far only part one has been uploaded. The first video outlines the hardware and software requirements for Iridium decoding and demonstrates the gr-iridium software. An Airspy and RTL-SDR Blog Patch Antenna are used for the hardware, and the software runs on DragonOS.
Rob writes that in part two he will demonstrate the use of iridium-toolkit, which can be used to extract data and recordings from the Iridium data provided from gr-iridium.
A few days ago SDRSharp version 1920 was released. SDRSharp (SDR#) is a popular Windows program that is affiliated with Airspy SDR dongles, but is compatible with RTL-SDR and various other SDRs as well. The latest version gets rid of the relatively resource heavy Telerik UI library and replaces it with a much lighter weight library.
The author of SDR#, @lambdaprog, notes that v.1920 reduces memory usage by 85% and CPU utilization by 50%. The new version also improves scalability for high sample rates and number of spectrum slices and improves plugin compatibility. Several AOR brand SDRs are also now supported in v.1920.
On the note regarding improved plugin compatibility, we've noticed that in the v.1920 update the IF Average plugin has begun working again. The IF Average plugin is used for Hydrogen line radio astronomy experiments. In the past we had to use older versions of SDR# to make it work. We have updated our Hydrogen line tutorial to reflect this.
Check the latest, greatest, lightest and fastest SDR# release with many performance improvements, new native modern UI, improved plugin compatibility, and a state-of-the-art DSP for difficult signal scenarios.
Over several years Aaron (@cemaxecuter) has been working on DragonOS, a popular Linux distribution that comes preinstalled with many different programs for software defined radios. A Linux distribution like this takes the hassle out of having to figure out how to compile and install various SDR programs, some of which can be quite tricky to get running.
Recently Aaron has also been working on WarDragon, which is a set of components that he's carefully tested and put together as a ready-to-use portable SDR kit. At its core is an Airspy R2 software defined radio and x86 Mini PC that comes with DragonOS pre-installed. It also includes a USB hub and GPS dongle, as well as an HDMI dummy plug for enabling remote desktop. Everything is held together by a 3D printed frame, and enclosed in a plastic carry hard case, with the external Ethernet, USB-C, and power ports routed to the outside of the enclosure.
Aaron kindly sent us a WarDragon for an honest review. We note that we do not get to keep the WarDragon, and it will be forwarded to someone else after this review.
WarDragon Outer EnclosureInside WarDragon (Intel PC hidden underneath)WarDragon with an LCD screen connected
Getting started with WarDragon is simple. Open the hard-shell case, connect an antenna to the Airspy, remove the dummy HDMI plug, connect a monitor to the HDMI port and a keyboard/mouse to a USB port, connect 12V power, and start the mini PC. A few seconds later DragonOS has booted, and you can run any of the programs pre-installed. And there are certainly a lot of programs available to play with as shown below.
List of software pre-installed in DragonOS
To get started with running it remotely we followed the instructions on the desktop to install OpenSSH, and ran the Rustdesk appimage stored in the 'post install' folder on the desktop. This allowed us to connect remotely to the unit via Rustdesk, a remote desktop interface. From there we were able to run software like SDR++, GQRX, and anything else that was preinstalled.
Aaron notes that every WarDragon will come with a free license for SDR4Space which is a command-line SDR tool for satellites. It can be used for scripting various operations, such as "recording IQ samples, predicting satellite passes and to start a record for a specific satellite and correct doppler at the same time".
The KrakenSDR software is also pre-installed on WarDragon, so the Airspy can easily be swapped out for a KrakenSDR too (or almost any other SDR as well). You can also add extra RTL-SDR units on the USB hub if desired.
Once you're done simply unplug everything and put the HDMI dummy plug back in. Close the enclosure up and you're ready to get on the move again.
One minor concern we have is that while the components are contained with the 3D printed frame, the frame itself is not held down inside the enclosure, so it can move a little during transport. Not a big deal if you are sensible about carrying it, but if you are expecting to throw the box around, something could eventually go wrong. Aaron also notes in the instructions that care should be taken to not leave WarDragon exposed to direct sunlight or in a parked car to avoid the 3D printed insert from warping. This could probably be solved by printing in a material like ABS.
Performance
The mini-PC included with WarDragon runs a 12th Generation Intel Alder Lake - N95 that can turbo up to 3.4 GHz, has 8GB of RAM, and a 256GB SSD built-in. These specs are powerful enough that the system is very snappy, software opens quickly, and software runs smoothly, even at the max 10 MHz bandwidth the Airspy supports.
These x86 mini-PCs appear to be quite a bit more powerful than their similarly priced ARM counterparts, but they do draw more power. The mini-PC running SDR++ and Airspy at 10 MHz oscillates around 20-30W of power draw, whereas a Raspberry Pi 5 running SDR++ only draws 5W.
What We'd Like to See Improved
Because the carry case is fully sealed when closed, the mini PC inside cannot be run when the case is closed, as there would be no airflow for cooling. We'd like to see some thought put into adding an external fan, and indeed Aaron has noted that in future versions he will be adding this. However, adding a fan does come at the expense of water tightness but we don't imagine many people would be throwing this in a body of water. As long as rain resistance is kept it should be alright.
We'd also like to see the SMA port brought out to the side, so an external antenna can be connected with the enclosure closed.
We can also imagine that some users might like to see a more expensive version that comes with a small screen and keyboard/mouse as part of the combo too. Aaron does note that the most common use case for operating via SSH or remote desktop via a field laptop though.
Price Review / Value
The Wardragon consists of the following components:
Beelink Mini PC (N95 8G+256G) - US$159 on Amazon.
Airspy R2 - US$169 on iTead.
Condition 1 11" Carry Case - US$36.99 on condition1.com
Other parts (cables, USB hub, USB GPS, HDMI dummy plug, outside connectors, 3D printed frame) - $US35 (estimated)
SDR4Space License - $US???
So that's a total of US$400 in parts (not including shipping costs) plus a bit of value from the SDR4Space license which is usually obtained on an inquiry-only basis. WarDragon currently sells for US$580. So for the extra $180, you are paying for the time to preinstall of DragonOS, drill the external mounting holes, 3D print the mount, the build time, testing time, and the ability to get support directly from Aaron himself. And we can't forget to mention the time Aaron puts into creating YouTube videos for WarDragon.
Obviously, if you are on a tight budget it would make sense to try and build your own system. But overall we think WarDragon is not a bad deal if your time is worth more and you just want a portable system to get up and running with DragonOS ASAP.
The Airspy HF+ and HF+ Discovery are popular and affordable software defined radios that have a focus on excellent reception on the HF bands. Recently @lambdaprog, the creator of Airspy products has released updated firmware for the Airspy HF+ series of products. The announcement on X is shown below.
We're excited to bring you a special firmware update for the #Airspy HF+ series. This release delivers several key enhancements:
New, more robust USB streaming stack Smoother and faster tuning Enhanced AGC behavior
The Airspy YouLoop is a no tune, broadband, small footprint, affordable LF to HF receive antenna that works indoors. Its modular construction facilitates experiments to understand where the Möbius inspired electrical design provides benefit.
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