Category: Airspy

Receiving GOES Weather Satellite Images with a Small Grid Antenna and an Airspy Mini

GOES is an L-band geosynchronous weather satellite service that can be received typically with a satellite dish. It produces very nice full disk images of the earth. In the past we’ve posted about Lucas Teske’s work in building a GOES receiving system from scratch (including the software decoder for Airspy and RTL-SDR receivers), devnullings post about receiving GOES and also this talk by @usa_satcom on decoding GOES and similar satellites.

Over on Twitter @usa_satcom has been tweeting about his experiments where he has been successfully receiving GOES L-Band weather satellite images with a small grid antenna and an Airspy Mini. In a Tweet he writes that the antenna is an $85 USD Hyperlink 1.9 GHz 22 dBi Grid Antenna made by L-com. A grid antenna may be more suitable for outdoor mounting for many people as they are typically lighter, smaller and more suitable for windy and snowy conditions. As the GOES satellite is in geosynchronous orbit, no tracking motor or tracking mount is required.

Cloud-SDR Releases New Client and Server Software for the RTL-SDR

Cloud-SDR is a company that aims to make using SDR over the cloud/network/internet easier. It allows you to set up a remote SDR server that you can access from anywhere. Previously Cloud-SDR was still in development, but now we recently received mail from Cloud-SDR programmer Sylvain that the client and server software has just been released for the RTL-SDR. It appears that it also currently supports the Airspy, BladeRF, SDRplay and PerseusSDR.

The email reads:

I am pleased to inform you that we have just released two softwares compatible with your devices :

  • The Cloud-SDR free client, a windows + Linux (to be released soon) client able to run locally RTL-SDR devices (check the news/turorials, we have featured several times dongles from your blog)
  • The Cloud-SDR streaming server (codenamed SDRNode) , a windows + Linux (to be released soon) multi-user configurable streaming server.

SDRNode is a commercial software but an evaluation version is already available. Both softwares can be downloaded from our store after registration.

Source code for the drivers are already released as open source software through our GitHub repo: https://github.com/cloud-sdr

You can find more details here :

The Cloud-SDR Network
The Cloud-SDR Network

To download the software you must register an account with them at https://store.cloud-sdr.com/my-account. The client is free but the server costs 110 euros for personal and hobby usage, although a 30 day trial version is available. Currently only the Windows Client and Server are available, but they write that Linux should be available soon.

We tested the software out with an RTL-SDR V3. The client installation process was a simple wizard and after installation we launched the Cloud-SDR client by opening the shortcut “cSDRc” in the Start Menu. We found that the hardware needed to be plugged in first for the client to recognize it. The client is basic, but can already demodulate USB/LSB/CW/AM/FMN without trouble. It also has some interesting features:

  1. Dual channel receiver: RXA and RXB are two totally independent receivers;
  2. Geographic integration: Display on map beacons, ADS-B reported airliners, known HF broadcast stations or any geo-localized information coming from the SDRNode server;
  3. GPS compatibility: plug a GPS receiver to your computer and track your location on the map, record signals with your position for later processing (coverage mapping etc.); display the UTC time;
  4. Digital Terrain Elevation: See the terrain elevation around your position, or in the direction of the antenna directly on the map (requires to download the free SRTM3 files from NASA, with 90m resolution);
  5. MP3 audio recording: record to mp3 the demodulated streams to reduce disk requirements;
  6. Chat with other users connected to the SDRNode Group: when used as a remote client for the SDRNode streaming server, you can interact with other users with messages or station spotting;
  7. Time-domain analysis: the MSR mode enables analysis of any sub-band and displays in real time the time domain signals of the selected spectrum portion. This sub-band can also be recorded (with geographic position if GPS is connected) and processed with provided MATLAB®.
The Cloud-SDR Client Software
The Cloud-SDR Client Software

Next we tested the evaluation version of the SDR-Node server software on a remote laptop with an RTL-SDR connected. Again installation was easy, just follow the wizard after ordering the evaluation version. SDR-Node installs itself as a Windows service which starts up automatically on boot. To set up the Node we followed the guide shown in the video below. To connect with the client you need to know the IP address of the remote computer, the port is 8080, and the certificate is displayed on the server PC SDR-Node dashboard. We note that we also had to disable the Windows firewall to get it to connect, but it should be possible to also add SDR-Node to the firewall whitelist.

https://www.youtube.com/watch?v=waRP7PIcOBc

When streaming it appears that only 1/4 of the SDR sample rate can only be sent over the network. There are also compression options which can be used on slower networks or the internet to reduce bandwidth. Using the interface while in network mode was slightly laggy, but the waterfall and audio was smooth.

Overall everything worked as expected and it looks to be a very useful tool. More information is available at cloud-sdr.com. Some already existing alternative remote SDR streaming software that supports the RTL-SDR includes rtl_tcp, the SDR Console V2 server, OpenWebRX and ShinySDR.

Airspy Competition Winners Announced

Last week the Airpsy team gave us the opportunity to give away some prizes, so we started a comment competition. The prizes were an Airspy R2 + SpyVerter, Airspy Mini + SpyVerter and SpyVerter. The competition closed yesterday with over 500 entries, and the winners have now been selected via random.org. Congratulations to the winners below:

Larry (Airspy R2 + SV)
If I am going to win something from this one stuff, me build internet remote receiver on hill in central Europe (CZ) for all readers and fans of rtl-sdr.com website, generally for all RTL SDR enthusiasts….. :-)))
Pour Felicitér 2017
Larry (Ladislav)

kevin (Airspy Mini + SV)
been a ham a couple years now. their are so many uses for sdr’s ! it’s so cool. just looking down the list of others comments, i was like ‘oh ya’ forgot about that idea. awhile back we did a demo at our ham club with a el cheapo sdr and it sparked some interest , would like to play around with some of the newest toys, worlds of diff in capabilities. ultimate goal is to find the right one for the clubs emergency trailer. seeing the bands and whats going on, is priceless :)

Josh (SpyVerter)
I’d love to finally get into the HF band!

If you’re a winner please check your email address for the competition winner email.

The competition produced some very interesting comments that show the diversity in projects that can be performed with a SDR receiver and we strongly encourage you to read through the comments if you are looking for project ideas.

If you didn’t win, sorry! Better luck next time. But please continue to follow us on Facebook and Twitter as we will have more competitions and more prizes to give away later in 2017!

Airspy New Year Competition: Comment to win Airspy and SpyVerter Prizes!

The team behind the Airspy have given us permission to give away three Airspy related prizes for the New Year Holidays! The first prize is an Airspy R2 + Spyverter, the second prize is an Airspy Mini + Spyverter and the third prize is a Spyverter.

The Airspy is a high performance yet low cost software defined radio with a 12-bit ADC and tuning range between 24 – 1800 MHz. It is an attractive device as its dynamic range exceeds all other SDRs in a similar price range. Its performance begins to approach that of the very high end expensive SDRs. High dynamic range means that weak and strong signals can coexist in the received spectrum without any overload occurring. We have previously written reviews of the Airspy R2 and Airspy Mini on our blog.

The Spyverter is a high performance upconverter that allows the Airspy to tune to LF/MW/HF frequencies between DC – 30 MHz. The Spyverter perfectly compliments an Airspy device as it is also a very high dynamic range device. It also works perfectly with the bias tee on our RTL-SDR.com V1/V2/V3 dongles. We previously reviewed the Spyverter here.

More information about these products can be found at airspy.com.

How to Enter

Competition is now finished. Winners will be announced and emailed shortly. Thanks to all who entered!

Winners: 

Larry (Airspy R2 + SV)
If I am going to win something from this one stuff, me build internet remote receiver on hill in central Europe (CZ) for all readers and fans of rtl-sdr.com website, generally for all RTL SDR enthusiasts….. :-)))
Pour Felicitér 2017
Larry (Ladislav)

kevin (Airspy Mini + SV)
been a ham a couple years now. their are so many uses for sdr’s ! it’s so cool. just looking down the list of others comments, i was like ‘oh ya’ forgot about that idea. awhile back we did a demo at our ham club with a el cheapo sdr and it sparked some interest , would like to play around with some of the newest toys, worlds of diff in capabilities. ultimate goal is to find the right one for the clubs emergency trailer. seeing the bands and whats going on, is priceless :)

Josh (SpyVerter)
I’d love to finally get into the HF band!

The winners were randomly selected using random.org, and all have now been emailed. If you’re a winner, please check your email and spam folder just in case.

Thank you all for participating! It’s really great to see all the variety in what projects people are doing. There were about 500 valid entries resulting in about a 0.6% chance of winning. Keep an eye out for future contests!

Simply make a comment on this post explaining what you’d do like to do with an Airspy or Spyverter if you won one.

PLEASE MAKE SURE TO ENTER YOUR EMAIL ADDRESS IN THE COMMENT FORM.
The address will only be visible to us, and we promise not to use it for any other purpose.

Rules: The winners will be selected at random. One entry per person only. You must legally be allowed to receive the prize.

Draw closes in one week on 3 January 2017, 11:59PM UTC Time.

airspy_giveaway2

Airspy Mini Christmas Sale – $80 USD

The Airspy Mini is a software defined radio with a tuning range of 24 MHz to 1800 MHz, 12-bit ADC and up to 6 MHz of bandwidth. It usually costs $99 USD and is the younger brother of the $149 USD Airspy R2.

Currently the manufacturer iTead is running a Christmas sale on the Airspy Mini. The sale price is $80 USD, which is a 19% saving. To get the sale price you need to click on the “Get coupon code here” link and then share the promotion to your Facebook, Twitter or LinkedIn account.

Update: They have given us a special blog coupon code “AS-RTLSDR-BLOG“. Just use this code at the checkout and it will apply the discount without the need to share. Edit: The blog coupon appears to have stopped working, an alternative one that is still working is “as3“.

The sale lasts from December 20, 2016 – January 3, 2017.

If you want to see more about the Airspy Mini then see our review here. Our other previous review comparing the Airspy R2 against the SDRplay RSP and HackRF may also be of interest as the Mini’s performance is very similar to the R2.

The Airspy Mini iTead Christmas Sale
The Airspy Mini iTead Christmas Sale

New Comparison Videos from Leif SM5BSZ: Airspy vs SDRplay vs Several Other SDRs

Over on YouTube Leif SM5BSZ has uploaded two new videos. The first video shows a set up that compares the Airspy and the SDRplay RSP on several lab tests that test for dynamic range performance at various frequency offsets. The Airspy definitely shows better results, but Leif notes that the differences are fairly small. The Airspy and SDRplay are two SDRs that compete in the mid range SDR price bracket.

Smaller is better, where each value represents the amount of attenuation required before saturation
Smaller is better. Each value represents the amount of attenuation used (in dBm) that causes a 3dB loss from reciprocal mixing
https://www.youtube.com/watch?v=Vg4sz1B5LCo

As lab tests can only approximate real world performance, in the next video Leif does a HF reception comparison on a real world antenna. In this video he compares our RTL-SDR.com V3 in the special direct sampling HF mode, a Funcube Pro+, SDRplay RSP, Airspy+Sypverter, Afedri Net, and an FDM-S1. The test injects an artificial signal and combines signals from a real antenna via an adjustable attenuator. Leif adjusts the attenuator to increase the antenna signals until the test signal strength is degraded by 3dB from reciprocal mixing/overload. That attenuation setting is then recorded.

The results for the daytime and nighttime results results rank the SDR’s in order from best to worst: FSM-S1 ($400 + shipping), Afedri ($259 + shipping), Airspy+Spyverter ($218 + shipping/$149 + shipping (mini)), SDRplay ($129 + shipping), Funcube Pro+ ($155 + shipping), RTL-SDR.com V3 direct sampling ($20 incl shipping). Interestingly the performance seems to correlate nicely with the unit cost. Of course the V3 in direct sampling mode can be significantly improved by using filtering on the front end, or just by using an upconverter and quadrature mode instead.

At the end of the video Leif also shows a final ranking of the HF performance of all radios tested in his previous videos.

Night time reception SDR ranking
Night time reception SDR ranking
Daytime reception SDR ranking
Daytime reception SDR ranking
Final Ranking
Final Ranking
https://www.youtube.com/watch?v=AyXyP9LO8n4

Portable Shortwave Spectrum Capture with an Airspy + Spyverter and Tablet

Over on his blog London Shortwave writes how difficult it can be trying to listen to shortwave radio stations when you’re indoors and in a big city filled with RF noise. His solution is a portable lightweight shortwave travel kit that he can take to the park. The kit that he recommends using includes an Airspy SDR with SpyVerter upconverter, a Toshiba Encore 8″ Tablet and an OTG USB adapter. His antenna is a portable dipole made from two pieces of 6m copper wire connected to a balun, then connected to the SDR with 3m of coax. The whole kit easily fits into a small metal brief case.

For the software London Shortwave uses SDR# and he enjoys capturing large chunks of the HF spectrum for replay later using the base band recorder and file player plugins for SDR#. In his post he also shows how he runs the Airspy in debug mode to restrict it to 6 MHz which is the maximum bandwidth that his tablet’s CPU can handle.

His post shows various example videos of his setup receiving some nice shortwave signals.

London Shortwave's SDR Kit.
London Shortwave’s SDR Kit.

Mile Kokotov’s SDR Overview and Dynamic Range Explanation

Mile Kokotov (Z33T) has been working on creating an overview page of some of the most popular software defined radios and software applications. In the past we’ve featured Mile’s videos several times on our blog and his page ties all the videos together nicely with text. On his page he briefly reviews the different types of RTL-SDR dongles as well as the Airpsy and SDRplay.

One very useful page he’s put together is his explanation of the “dynamic range” concept, which is probably the most important characteristic when it comes to a radio. According to Miles description dynamic range measures the ability of a radio to “receive very weak and very strong signals at the same time, without overloading”. His page also explains how decimation in software can help improve the dynamic range without needing to improve the hardware.

Mile’s page is not yet 100% finished, so we advise you to keep an eye on it for new information.

Explaining dBFS (decibels relative to full scale)
Explaining dBFS (decibels relative to full scale)