Category: News

CubicSDR: New open source, cross platform SDR software

Over on YouTube a video showing off a preview version of a new cross platform and open source SDR software program has recently been uploaded. The software is named CubicSDR and aims to support all major operating systems including Linux, Windows and OSX. The code can be downloaded from its GitHub page at CubicSDR currently supports the RTL-SDR, but in the future hopes to support the HackRF and other SDR’s. They also hope to eventually integrate several demodulation filters, make managing multiple SDRs easy and allow for scripting of custom demodulators.

PortableSDR now on Kickstarter

Back in November, 2014 we posted about the PortableSDR, a 0 – 35 MHz portable software defined radio transceiver that was the third place winner in the Hackaday Prize competition. The PortableSDR project is gaining traction and now has a Kickstarter campaign. They write:
The Portable Software Defined Radio, or PSDR, is an Open Source, Fully stand-alone HF/Shortwave Software Defined Transceiver. It includes a Vector Network Analyzer and Antenna Analyzer as well as GPS. It’s built for rugged portable use. It is designed to be a flexible platform for development, a learning aid, and and a useful instrument for electronics enthusiasts. Features:
  • Coverage from 0 to 35MHz
  • Waterfall display that lets you see radio signals
  • Receives AM, USB (Upper Side Band), LSB (Lower Side Band), and Morse code (CW)
  • Modulates USB and LSB signals
  • Variable bandpass filter
The campaign hopes to raise $60,000 USD to aid in the development of the hardware and software and with the manufacturing process. The kickstarter is offering kits at various stages of completion from $250 to $475 and a fully assembled kit at $499. They note that the current PSDR2 that you will receive from the Kickstarter is still a development version, not the final product. The PSDR2 is missing some key features that will be in the final version like filters and output amplifiers.
The PSDR v.1
The PSDR v.1

We now sell RTL-SDR’s with the R820T2 Tuner and 2x Telescopic Antenna + R820T2 Tests

We now sell R820T2 RTL-SDRs on (currently for US customers only sorry!) and are currently running a $2 off promotional sale which will expire January 31, or until the first batch of stock runs out. Compared to the other choices our RTL-SDR Blog branded units come with several improvements which we list below.
  • Use of the R820T2 tuner which has been shown to have slightly better noise performance and give better SNR compared to the standard R820T chip.
  • Use of improved component tolerances which help the circuit to operate at its optimum.
  • Use of a surface mount 28.8 MHz oscillator instead of the “can” type. We believe this will reduce the PPM offsets to below 30 in most dongles, but note we can not guarantee this.
  • Improved “full braid” coax cable on the antenna base which has significantly lower loss compared to the coax used on other brand RTL-SDR stock antennas.
  • Comes with 2 x telescopic antennas. 1 x 9.5 cm to 31.5 cm telescopic antenna and 1 x 20 cm to 1.5 m telescopic antenna. Great for beginners to receive a wider range of frequencies without buying extra antennas.
  • No IR LED. The IR LED is useless for SDR operation and the long legs on the LED may pick up interference.
We currently have two options for sale that are shown below. The dongle only unit is perfect as a replacement dongle or for those who just want to try out the R820T2 chip. The unit with the two telescopic antennas is great for beginners who don’t have any good antennas already. We also have limited quantities of some MCX male to various female adapter sets for sale which work out to be much cheaper than when buying them individually. Buying a set will have you ready for almost any antenna connection you need. The pigtail adapters come with 20cm of RG316 cable and the straight adapters don’t use any cabling. Pigtail Adapters SetMCX -> Various Female Pigtail Adapter Set – $19.99 Straight MCX Adapters SetClick here to buy a MCX -> Various Female Straight Adapter Set - $16.99 Currently because of the way Amazon works, we can only ship to US customers, but we may ship overseas in the future. Shipping from Amazon is fast and free if you spend over $35 or are a Prime member. Returns from faults are also easy and welcome. If you are overseas and can’t buy from us, the alternatives for R820T2’s are the Nooelec R820T2 (US shipper), the Cosycave R820T2 (ships from Channel Islands, UK) and there are also some Chinese R820T2 (Chinese shipper) models available on ebay. We also offer unofficial support over on our forums. If you do buy from us we hope that you will consider leaving a product review on the Amazon page as that will really help us out as small time Amazon sellers. As an added bonus, we will also have our e-book on sale from January 16 to January 23 at $6.99 USD, reduced from $9.99 USD. We also performed some simple performance tests on the R820T2 which we show below.

R820T2 Tests

The first test was a noise floor test. We used rtl_power and ran a noise test with maximum gain and a 50 Ohm terminator connected for 15 minutes over the entire receivable frequency band. We averaged the results over three different R820T dongles and three R820T2 dongles to remove dongle to dongle variances. The results show that noise floor on the R820T2 is around 2-3 dB lower at most frequencies. R820T2_NoiseFloor Next we tested the SNR with the gain set to zero using a HackRF as the signal source. The results show that the R820T2 is about 2-5 dB more sensitive depending on the frequency. Also, compared to the R820T, the sensitivity seems to be significantly better at 1.5 GHz to 1.8 GHz as all tested R820T units could not even detect the test signal above 1.5 GHz without increasing the gain. R820T2_SNR

Oliver Jowett HF Driver Test

The R820T2 should have better performance at HF frequencies when using the experimental Oliver Jowett drivers. We tested an R820T and R820T2 on broadcast AM reception. At broadcast AM frequencies the R820T starts with a very high noise floor after starting it for the first time, but after about 5 minutes seems to settle down to a lower noise floor shown in the right image below. In comparison the R820T2 starts at a low noise floor almost immediately. We are unsure why there is a settling time in the first place. Even after the settling time the R820T2 had better reception and SNR as shown in the comparison image below. Both dongles were set to the second highest gain setting. R820T2vR820T_BAM At 15 MHz international broadcast AM can be clearly heard with Oliver’s drivers. The R820T2 gets clear reception with a very low gain setting, whilst the R820T can obtain similar SNR with a higher gain setting. Though with a higher gain setting used on the R820T more noise seems to appear as can be seen in the comparison image below. R820T2vsR820T_14MHz

Low Loss Coax

We also tested the low loss coax cable used in our RTL-SDR Blog branded antenna bases and found that it had approximately 3 dB less loss compared to the standard cable when used at most frequencies above 100 MHz. The test used a 1M length of each coax, with the HackRF as the signal generator. The direct connection test used a straight MCX->SMA Male adapter to directly connect the HackRF and RTL-SDR together. Low_Loss_Coax

New Products from Nooelec: Cheaper E4000 Dongles and a 9:1 Balun

The online store Nooelec has recently started selling two new RTL-SDR related products. The first product is a lower cost RTL-SDR dongle with the E4000 tuner (ebay). The E4000 tuner was one of the original tuner chips used in RTL-SDR dongles when they were first discovered. Unfortunately Elonics, the company that owned the rights to the chip went under and the production of E4000 chips stopped, making them rare and expensive. The E4000 tuner has a tuning range of approximately 55 MHz – 2300 MHz, compared to the R820T tuner which has a range of around 24 – 1766 MHz. The cheaper R820T is better in most cases, but if you need the higher frequencies the E4000 may be an option. The new E4000 dongle is currently selling for around $50 USD, compared to the other E4000 models which went for around $100 USD.
E4000 Dongle from Nooelec
E4000 Dongle from Nooelec
They have also begun selling a low cost 9:1 balun for about $10 USD (ebay) which can be used with a long wire (or random wire) antenna when receiving HF on the RTL-SDR with an upconverter. The impedance of a long wire antenna is approximately 450 Ohms (very approximate, impedance varies with frequency and length). A 9:1 balun allows a match with a 50 Ohm receiver, which is close enough to the 75 Ohm input of the RTL-SDR.
Nooelec 9:1 Balun
Nooelec 9:1 Balun RTL-SDR Giveaway

The guys at the blog have teamed up with Nooelec to bring everyone a worldwide competition giveaway of 20 RTL-SDR prizes. The top prizes include the rare E4000 chip tuners, ham-it-up upconverters, adapters and aluminium enclosures while the regular prizes include an R820T2 RTL-SDR set. To enter the competition all you need to do is leave a comment on their competition post. The competition is open for one week from 11 December 2014 to 18 December 2014. The complete list of prizes are quoted below.
Three (3) Complete NESDR XTR HF SDR packages including: NESDR XTR SDR Set (E4000 chip) Ham It Up upconverter Upconverter Enclosure (silver) Male MCX to male SMA pigtail (SDR cable) Male SMA to female BNC adapter (antenna adapter) Estimated $129.95 value Five (5) Complete NESDR Mini 2 HF packages including: NESDR Mini 2 SDR set Ham It Up upconverter NESDR Mini 2 enclosure (silver) Upconverter enclosure (silver) Male MCX to male SMA pigtail (SDR cable) Male SMA to female BNC adapter (antenna adapter) $111.95 value Twelve (12) NESDR Mini 2 SDR sets $25.95 value and NooElec Giveaway and NooElec Giveaway

Updates to a Month of RTL-SDR by Keenerd

Back in August of this year RTL-SDR code contributer Keenerd aka Kyle Keen ran an Indiegogo campaign to raise funds to pay for him to work on upgrading RTL-SDR related code for one month. As Kyle only counts the days he manages to put a good effort in towards the upgrades, the coding is still ongoing. He recently put out an update which we quote below.
Programming Report – Week 3 Hey all, sorry about dropping off the radar there.  There were several large unexpected events in recent months, but nothing bad.  I’ve still been hacking on the project.  An anonymous donor gave me a Lyons DSP textbook, which I’ve been working through for more solid foundations.  But studying doesn’t generate any new code for you to play with, so hasn’t been counted towards the project. I’ve also been working on a very ambitious ADS-B related side project.  It is something no one has ever done before with the RTL-SDR, but mathematically it is feasible and progress is steady.  Not anywhere near for a release (and might yet be impossible in practice), and thus also hasn’t been counted towards the project. So what has been completed since the last report? * Automatic audio gain.  Crucial for AM/SSB listening. * Audio padding (constant rate audio).  If you are streaming rtl_fm, this will prevent stutters when the tuner is busy hopping. * Heatmap fixes.  The font is downloaded automatically and image slicing is completed.  Run rtl_power 24×7 but render a heatmap of only the last hour, for example. * Rtl_power fixes.  Including one tricky corner case that caused crashes. Also a big thank you to Kacper Michajłow who fixed and fleshed out a couple of Windows issues that were giving me trouble. 25 days remain.  As always, if you have comments or suggestions you can reach me by email or in ##rtlsdr.
The latest feature requests and links to the GitHub repositories and Windows builds can be found at monthrtlsdr

Airspy Second Batch of Preorders Available

The Airspy software defined radio recently completed its first round of 400 pre-orders. Now the second round of pre-orders has become available over on the manufacturers web store. It is priced at $199 USD and they expect the orders to be shipped around the middle of December. If you were unaware the Airspy is an RX only SDR developed by the author of the SDR# software. It has a tuning range of 24 MHz to 1.7 GHz, up to 10 MHz of instantaneous bandwidth and a 12-bit ADC. The full list of features is shown below.
  • Continuous 24 – 1750 MHz RX range with no gaps
  • 3.5 dB NF between 42 and 1002 MHz
  • Tracking RF filters
  • 35dBm IIP3 RF front end
  • 12bit ADC @ 20 MSPS (80dB Dynamic Range, 64dB SNR, 10.4 ENOB) – Yeah, size does matter.
  • Up to 80 MSPS for custom applications
  • Cortex M4F @ up to 204MHz with Multi Core support (dual M0)
  • 1.5 ppm high precision, low phase noise clock
  • 1 RTC clock (for packet time-stamping)
  • External clock input (10 MHz to 100 MHz via MCX connector) – Ideal for phase coherent radios
  • 10 MHz panoramic spectrum view with 9MHz alias/image free
  • IQ or Real, 16bit fixed or 32bit float output streams
  • No IQ imbalance, DC offset or 1/F noise at the center of the spectrum that plagues all the other SDRs
  • Extension ports: 16 x SGPIO
  • 1 x RF Input (SMA)
  • 1 x RF Output (Loopthrough, U-FL)
  • 2 x High Speed ADC inputs (up to 80 MSPS, U-FL)
  • 4.5v software switched Bias-Tee to power LNA’s and up/down-converters
The Airspy was recently reviewed in two videos by W9RAN, the second video showing some sensitivity measurements. There are also various other videos of the Airspy in action now on YouTube.
Airspy Software Defined Radio
Airspy Software Defined Radio

HackRF Blue: A Lower Cost HackRF

Earlier in the year the HackRF One was released by Micheal Ossmann. It is a transmit and receive capable software defined radio with a 10 MHz to 6 GHz range which currently sells for around $300 USD. Since the HackRF is open source hardware, anyone can make changes to the design and build and sell their own version. The HackRF Blue is a HackRF clone that aims to sell at a lower cost. By sourcing lower cost parts that still work well in the HackRF circuit, the team behind the HackRF Blue were able to reduce the price of the HackRF down to $200 USD. They claim that the HackRF Blue has the same performance as the HackRF One and is fully compatible with the HackRF software. They are currently seeking funding through an IndieGoGo campaign. Their main goal through the funding is to help provide underprivileged hackerspaces with a free HackRF.
The HackRF Blue
The HackRF Blue