Category: News V3 Stock Availability and Holiday Shipping Times

This is just an update post for those wishing to purchase or are waiting on delivery for items from our store at

Amazon USA

The V3 has proven to be more popular than we anticipated and Amazon ran out of stock a few weeks ago. New stock should be arriving at the Amazon warehouses early next week, but we don’t know how long Amazon will take to process the stock and put it back on the shelves. It should hopefully be ready in under a week.


For international orders from our Chinese warehouse, please be aware that international shipping is quite slow at the moment, due to the peak season parcel rush. The international mail system struggles to cope with mail at this time of the year due to a vast increase in Christmas parcel volume. Delivery times are still typically under 4 weeks but for some parcels, and to some countries we can expect shipping times of up to 6 weeks or longer. 

Some people have noted that parcels ordered after a previous order have arrived earlier. We use the same postal system as everyone else (there’s only really one international air mail system!), but what can happen is that on some days the parcels may get a direct flight, and on other days they may get an indirect flight. Those indirect ones can end up taking much longer. Also planes can break down, parcels can miss a connecting flight or security can hold a container of many parcels for days just because they saw one suspicious parcel inside. Thus international parcel delivery times have a very large scattering, ranging from less than a week to six weeks or more. We thank you for your patience if your parcel happens to end up on the slower end of the scale. But if your parcel does end up taking over 6 weeks please let us know as we may be able to open a lost parcel investigation. If your parcel is lost it will be resent or refunded on your preference.

If you are tracking a parcel we recommend, and Try all three as sometimes one has more up to date tracking than another. Please note that we’ve found that around this time postal workers will often not bother to scan the tracking label on parcels, since they are rushing so much. This can cause a lack of tracking updates for a while. Also if there are queues for customs checks in your local country the parcel can wait around in the container without a scan for a long time, until customs gets to it.

We have several shipping methods available. China Post/Swiss Post/HK Post are about the same speed once they leave. But generally Swiss/HK post are faster to leave China. China Post parcels can sometimes take a few extra days to pass through security. Some countries which support it, will automatically be upgraded to EMS ePacket priority mail. We also have some new special methods for some countries which are still air mail, but use a faster more direct flight to the destination. Of course the more expensive express mail services like DHL/UPS/Aramex are also available, but even they have about a 1 week shipping delay at the moment.

However, despite these shipping time uncertainties, the majority of parcels still seem to be making it through the postal system in a timely manner. Thanks to everyone for supporting the blog!

R820T2 Register Description Data Sheet Now Available

Recently Luigi Tarenga wanted to do some work on developing RTL-SDR drivers, so he emailed Rafael Micro requesting some additional documentation about the chip. Usually previous requests to Rafael Micro for such information seem to have gone unanswered, but this time it seems they have decided to publicly released the Register description document for the R820T2 chip.

Previously the R820T datasheet was leaked/released to the public, but the information in the datasheet did not help much with driver development. This register description document describes the function and configuration bits for the registers on the chip, and may be useful for people wanting to develop better drivers for the RTL-SDR.

We have uploaded a copy on our server here.

Description of some of the registers in the R820T2 chip.
Description of some of the registers in the R820T2 chip.

The 2016 /r/rtlsdr Reddit Giveaway

The mods of the /r/RTL-SDR community on the Reddit discussion platform are currently hosting an RTL-SDR themed giveaway. The prizes up for grabs include units which have been donated from ThumbNet ( and us at The prizes also include several donated home brew projects including filters and downconverters. See the table at the end of this post for the full prize list.

To enter all you need to do is write a comment on the competition thread at and mention what you like about SDR and what you hope to do with a prize if you win. While you’re at it we strongly suggest subscribing to /r/rtlsdr if you haven’t already as that is one of the the largest and most active communities of rtlsdr users on the web.

The competition closes on December 3rd and only one entry per household is allowed.

Place Prizes Description
1st-2nd 2 ThumbNet – N3 SDR RECEIVER
3rd-5th 3 RTL-SDR Blog V3 Dongle + Antenna Kit
6th-7th 2 $25 ThumbNet – Gift Certificate
8th-11th 4 Blog V3 Dongle Only
12th 1 PA0RDT Mini-Whip Antenna
13th-14th 2 Blog Broadcast FM Filter
15th-16th 2 Up to ~4.5GHz Microwave Downconverter
17th 1 70cm HamSat / 433 Combline BPF
18th-20th 3 Choice of Custom Made 5 Pole HF BPF/LPF/HPF

New Low Power RTL-SDR’s for Stratux ADS-B Receivers

Stratux is an RTL-SDR based project that gives small plane pilots access to ADS-B data, without having to purchase an expensive commercial ADS-B installation. It consists of software that runs on a Raspberry Pi, and two RTL-SDR dongles to receive both 1090 MHZ ADS-B, and 978 MHz UAT. The decoded data is then streamed via WiFi to a tablet running navigation aide software with charts for pilots.

Typically Stratux kits come with two standard ‘Nano’ styled RTL-SDR dongles. However, users of the Stratux system have been reporting problems with overheating, and with the Pi struggling with the high current demands of a typical setup which includes two RTL-SDR dongles, active WiFi broadcasting, a GPS unit and an optional cooling fan. A typical RTL-SDR dongle draws 280 mA, so two dongles are already pulling 560 mA.

Chris, creator of the Stratux software and seller of Stratux kits has just released a new low power RTL-SDR dongle (kit with antennas). The cost is $35 USD for two dongles (one for 1090 MHz and one for 978 MHz). The dongle obtains its low power feature by using a switching regulator instead of a linear regulator as the main 3.3V power regulator on the PCB. Normally you would not want to use switching regulator for the main regulator in an RF device because they are very noisy in terms of RF interference generated. However switching regulators are much more efficient compared to linear regulators, and thus save a lot of current wastage. Other dongle manufacturers like ThumbNet have actually gone the other way, removing the secondary 1.2V switching regulator from the standard dongle design, and using a linear regulator instead. The ThumbNets end up with lower noise, but draw 400 mA of current. 

With the switching regulator the new Stratux dongles only draw about 185 mA, a saving of almost 100 mA. They also generate 0.5W less heat. Users of the Stratux system have so far been impressed with them and have not noticed any appreciable difference in ADS-B performance. We think that these low power dongles might also be of interest to people using them on mobile phones or battery/solar powered remote installations.

The new Stratux low power RTL-SDR dongles.
The new Stratux low power RTL-SDR dongles.

During testing, Chris found that there was no significant noise floor increase visible on the 978 MHz  & 1090 MHz frequencies. Most of the switching noise increase appears to be on the lower frequencies, but those frequencies are not relevant for the Stratux use case anyway.

Chris was kind enough to send us some samples of the new low power dongles. First we ran a noise floor scan with rtl_power to determine the effect of the switching regulator. The results show that the spurs and noise floor readings have definitely increased by a significant amount, with an especially large noise floor rise below 400 MHz. In SDR# wandering switching noise spurs are also visible throughout the spectrum, but they tend to weaken in strength once an antenna is connected.

Stratux vs Standard Dongle vs V3 Dongle Noise Floor Scan
Stratux vs Standard Dongle vs V3 Dongle Noise Floor Scan

Fortunately, ADS-B is very tolerant to spurs and is generally not affected by this type of noise. We’ve only given the Stratux a quick test on ADS-B so far, but when compared against another ‘nano’ styled dongle the Stratux performed nearly identically (in fact even a little better) in terms of messages received. The two dongles were connected to the same antenna via a splitter and we logged the number of messages received in 10 minutes.

Quick ADS-B Reception Test
Quick ADS-B Reception Test

In conclusion the Stratux RTL-SDR set out to solve the mobile power issues suffered by people using the Stratux system. It has achieved that with an over 100mA saving in current use. The new Stratux dongle is much noisier, but the noise does not appear to significantly affect ADS-B reception as seen by our results and from the reports from Stratux users who beta tested this dongle.

Chris has also created a post on Reddit /r/stratux which talks a bit more about the new dongle.

SDRuno Updated to V1.1: Now supports up to 2.4 MSPS for the RTL-SDR

SDRuno is the official software for the SDRplay RSP software defined radio. Recently they’ve released version 1.1 which contains various new features and bug fixes for the RSP. The SDRuno Cookbook by NN4F & KD2KOG has also accordingly be updated with information about the new features.

In addition they’ve also now increased the previous 0.96 MSPS sample rate limit which was enforced for all third party radios running via EXTIO drivers. The new limit is 2.5 MSPS (with 2.4 MSPS being the limit for the RTL-SDR). This is great news for RTL-SDR users as SDRuno for the RTL-SDR is now almost as functional as in other SDR software like SDR#, HDSDR and SDR-Console. The change log is pasted below:

Version 1.1 (11th November 2016)
Bug Fixes

  • 1.04.1 – fixed issue where highlighted filter wasn’t always the one loaded.
  • Waterfall in combo mode now flows the same direction as other modes

Updates (RSP only V1.1)

  • Tighter integration of RSP controls
  • Calibrated power measurement
  • Automatic S-Meter calibration
  • SNR meter
  • dBm scale for both SP1 and SP2 windows
  • Automatic frequency calibration
  • Support for IARU S-Meter standard
  • Zoom to VFO button in SP1 window
  • More improvements to AGC scheme
  • More improvements to DC offset compensation scheme
  • Reversed default mouse wheel scroll direction
  • Waterfall in combo mode direction can be reversed in the same way as other modes
  • Added extra frequency step sizes
  • LSB / USB filter presets back to being the same
  • USER filter preset renamed to DIGITAL
  • Support for both gain and gain reduction displays
  • Updated hardware driver – now reports as SDRplay device

Updates (EXTIO only V1.05)

  • maximum bandwidth changed to 2.5MHz
SDRuno Version 1.1 Running a RTL-SDR at 2.4 MSPS
SDRuno Version 1.1 Running a RTL-SDR at 2.4 MSPS

The ThumbNet N3 is now Shipping

The latest RTL-SDR receiver from Thumbnet, the Thumbnet N3 is now shipping out. Back in October we received a sample of one of their prototypes and found it to have a very low noise floor since they have replaced the 1.2v switching regulator with a linear regulator.

ThumbNet is a company that is hoping to provide low cost satellite deployments, and make use of volunteers around the world with RTL-SDR’s to help track them. The RTL-SDR’s and antenna kits are provided to schools and educational institutions for free by ThumbNet, in exchange for students setting up and monitoring a satellite tracking station.

In their release email they wrote:

ThumbNet would like to send a very large “Thank You!!” to all of you who have supported us by purchasing one of our surplus N3 SDR receivers, and we wanted to take a second and let you know that we’re excited to announce that the N3’s have left the factory and will begin shipping.

The support has been tremendous and we have a backlog of many hundreds of receivers to get out. We will be working extremely hard, over the coming days to get them all delivered as quickly as possible (Orders will be shipped in the order they were received.).

Don’t forget that there are accessories in the ThumbSat Store ( ) that may be of value to you, such as adapters, cables or power supplies to let you get the maximum performance from your ThumbNet N3. 

A handful of independent tests have been done on the Qualification Models of the N3, and the results have been quite positive.  If interested, you can read some of the reviews at the following links. –


Thank you again for supporting ThumbNet and we hope the N3 exceeds all of your expectations!!

The Thumbnet N3 with its metal case add on.
The Thumbnet N3 with its metal case add on.

HDSDR Beta 2.75 Released

A new beta version of HDSDR has recently been released. HDSDR hasn’t been updated since 2013, so it is good to see that the author is back in action. HDSDR is a free general purpose SDR receiver, similar in nature to other programs like SDR# and SDR-Console. It was one of the first programs to work with the RTL-SDR dongle and despite a lack of recent updates is still a very solid piece of software.

The new HDSDR is version 2.75 Beta1 and the changes include:

  • more recording options
  • support for 8bit sampling format
  • HDSDR runs without output soundcard
  • support for 8k display resolution (7680×4320)
  • extended ExtIO capabilities
  • many fixes and improvements

The main visual difference we’ve noticed so far is the addition of a text dBM meter under the S-Units meter. We also discovered some new color palettes.

HDSDR Beta running a new bright grayscale color palette.
HDSDR Beta running a new bright grayscale color palette.

FlightAware Release their Pro Stick Plus: An ADS-B Optimized RTL-SDR with LNA and 1090 MHz Filter Built in

Back in March of this year we posted about the release of the FlightAware “Pro Stick”. The Pro Stick is FlightAware’s ADS-B optimized RTL-SDR dongle. It uses a low noise figure LNA on the RF front end to reduce the system noise figure, thus improving the SNR at 1090 MHz. Because the added gain of the LNA can easily cause overload problems if there are other strong signals around, FlightAware recommend using one of their 1090 MHz ADS-B filters in front of the dongle to prevent overload.

FlightAware have just come out with the “Pro Stick Plus” which is the same as their Pro Stick, but now with the 1090 MHz filter built into the dongle itself. The Pro Stick Plus costs $20.95 USD on Amazon, which is a good deal cheaper than buying the standard Pro Stick ($16.95 USD) plus their ADS-B filter ($19.95 USD), which totals $36.90. Customers outside of the USA can purchase the Pro Stick Plus from seller WiFi Expert on eBay for $29.95 USD. is a company that specializes in live air travel tracking. Most of their data comes from volunteers running RTL-SDR ADS-B receivers.

The new Pro Stick Plus RTL-SDR based ADS-B Receiver from FlightAware.
The new Pro Stick Plus RTL-SDR based ADS-B Receiver from FlightAware.

Over on their forums and on Amazon, they announced the device and specs. They wrote:

FlightAware is excited to announce the next evolution of USB SDR sticks for ADS-B reception! The new Pro Stick Plus USB SDR builds on the popular Pro Stick by adding a built-in 1090 MHz bandpass filter. The built-in filter allows for increased performance and range of reception by 10-20% for installations where filtering is beneficial. Areas with moderate RF noise, as is typically experienced in most urban areas, generally benefit from filtering. By integrating the filter into the SDR stick, we are able to reduce the total cost by more than 40% when compared to buying a Pro Stick and an external filter.


  • Filter: 1,075 MHz to 1,105 MHz pass band with insertion loss of 2.3 dB; 30 dB attenuation on other frequencies
  • Amp: 19 dB Integrated Amplifier which can increase your ADS-B range 20-100% more compared to dongles from other vendors which can increase range 10-20% over a Pro Stick in environments where filtering is beneficial
  • Native SMA connector
  • Supported by PiAware
  • R820T2 RTL2832U chips
  • USB powered, 5V @ 300mA

Note that this dongle is only for ADS-B at 1090 MHz, and not for 978 MHz UAT signals, as the filter will cut that frequency out.

Back in April, we did a review of the original Pro Stick. We found its performance on ADS-B reception to be excellent, but only when a filter was used. The low NF LNA theoretically improves the SNR of ADS-B signals by about 7-8 dB, but in reality there is too much gain causing signal overload everywhere, thus making reception impossible without the filter. Rural environments may not need a filter, but in a typical urban or city environment strong FM/TV/GSM/etc signals are abundant and these signals easily overloaded the Pro Stick when no filtering was used. This new Pro Stick Plus dongle completely solves that problem at a low cost with its built in filter.

Remember that if you are using a run of coax cable between the LNA and RTL-SDR, then it is more optimal to use an external LNA, like the LNA4ALL. Only an external LNA mounted near the antenna can help overcome coax, connector, filter and other losses as well as reducing the system noise figure. The FlightAware dongles are the optimal solution when they are mounted as close to the antenna as possible. This is usually the case when running the FlightAware feeder software on a Raspberry Pi.

We hope to soon review the Pro Stick Plus, however we assume it will operate nearly identically to the Pro Stick + FlightAware ADS-B filter combination.