Tagged: airspy

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

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

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

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.

Demuxing Frames and Generating Images from the GOES Weather Satellite

In his latest two posts Lucas Teske continues with his series about receiving and downloading weather satellite images from the GOES satellites. In past posts he’s show us how to receive the signal with a satellite dish and Airspy or RTL-SDR (part 1), how to demodulate the signal (part 2), and how to extract frames from the demodulated signal (part 3). Lucas has recently completed his series with parts 4 and 5 having just been uploaded.

In part 4 Lucas shows how to parse the frames and get the packets which will ultimately be used to generate the weather image files. His post explains how to de-randomize the frame data which is initially randomized to improve performance, how to add Reed Solomon error correction, how to demux the virtual channels and the packets and finally how to save the raw packet.

The packet structure
The packet structure

In part 5 Lucas shows us how to finally generate weather satellite images from the GOES satellites. He notes that there is a problem with the LritRice compression method used by NOAA, because the library is currently broken on Linux. So he made a workaround which involved making a Windows application that runs through Wine for decompressing the data. Once the files are decompressed he uses the xrit2pic program which can open the generated .lrit files and convert them into images.

In the future Lucas mentions that he will write a user guide to his LRIT decoder, and make the whole decoding process more user friendly for people who do not care so much about the actual decoding process. Below are some images that Lucas was able to receive with his system.

GOES Full Disk Image of the Earth
GOES Full Disk Image of the Earth
Weatherfax (WEFAX) Image
Weatherfax (WEFAX) Image

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)

Building a Frame Decoder for the GOES Weather Satellite

Yesterday we posted about Lucas Teskes (@lucasteske) success in building a demodulator for the GOES weather satellite. Before that he also showed us how to build an antenna system to receive GOES with an Airspy or RTL-SDR dongle.

Today Lucas continues with part three of his series on GOES decoding. This time he shows how he has built a frame decoder to process the output of the demodulator, and also gives us a link to his code. The decoder is written in C code. Lucas’ post explains how to sync the frame by detecting the preamble, perform convolution encoding to generate a parity and help correct any errors, and decode the frame data.

In part four Lucas will show us how to parse the frame data and extract the packets which will eventually form an image file of the earth.

A decode frame viewed as an image. This shows the syncword pattern and frame counter.
A decode frame viewed as an image. This shows the syncword pattern and frame counter.

Creating a GOES Weather Satellite Demodulator

Last week we posted about Lucas Teske’s (@lucasteske) experience with setting up an antenna system that can receive the geostationary GOES weather satellites. He set up a dish antenna, feed, LNA and filter and was able to successfully receive the GOES signal with an RTL-SDR and Airspy.

Now Lucas has uploaded his second post where he discusses how to demodulate the GOES signal. The GOES satellites transmit a Low-Rate Information Transmission (LRIT) signal which contains full disk images of the earth as well as other weather data from the secondary Emergency Managers Weather Information Network (EMWIN) signal.

In order to demodulate the signal Lucas wrote a BPSK demodulator in GNU Radio. His post goes into good technical detail and shows exactly how the demodulator is constructed. Basically the the BPSK signal is first decimated down to 2.5e6, normalized with an AGC, then cleaned up with a Root Raised Cosine Filter. From there the signal goes through a Costas Loop PLL to receover the carrier wave, then a Clock Recovery MM block to recover the symbol clock. The data is then output to a TCP pipe for the decoder.

In the upcoming third part of his article Lucas will show us how to actually turn the demodulated data into an image of the earth.

GOES LRIT Decoder
GOES LRIT Decoder