Category: News

Meteor M-N1 Still Working, Meteor M-N2 Still Down

The Meteor M N-2 is a polar orbiting Russian weather satellite that was launched in July 2014. It transmits with the LRPT protocol which allows us to receive weather satellite images that are of a much higher resolution than the NOAA APT satellites. For a while since the launch RTL-SDR users had a good time receiving beautiful images from Meteor M-N2, but unfortunately since late last year the N2 LRPT transmitter has been turned off, due to technical problems with the IR sensors as cited by Russian meteorologists.

Fortunately for Meteor N2 enthusiasts the old Meteor M N1 satellite which was thought to be dead sprung back into life around November 2015. Recently Matthew A., a reader of our blog wrote in to let us know that while N2 is still not transmitting, N1 is still transmitting, albeit with somewhat distorted images. Matthew also mentions this link: http://homepage.ntlworld.com/phqfh1/status.htm, which contains up to date info on the status of all weather satellites. He also writes: 

  • While transmissions are readily detectable and decodable at night, it seems that M N-1’s infrared sensors are not functioning. Yielding only black, with the typical noise bars of Red, Green, or Blue
  • As has been previously mentioned, Meteor MN-1’s stabilization system has obviously failed, and the horizon is clearly visible. Perhaps not of scientific value, but certainly beautiful. 

We also note that there are several comments over on the Meteor-M N2 news and support website regarding receiving images from N1 and N2. It seems that sometimes N1 also has some problems with transmission, but they are usually quickly fixed.

Meteor M-N1 Image Received by Matthew
Meteor M-N1 Image Received by Matthew
 

Nooelec + AmateurRadio.com RTL-SDR Competition now Running

Hot on the tails of our own competition which has now closed, Nooelec and AmateurRadio.com have teamed up to create a giveaway for a HackRF One and 40 RTL-SDR dongles (some even bundled with upconverters)! They are giving away:

  • 1x HackRF One HF SDR Bundle (Includes upconverter and adapters)
  • 3x NESDR XTR+ HF bundles (a.k.a E4000 RTL-SDR + Upconverter)
  • 2x NESDR Mini 2+ HF bundles (a.k.a R820T2 RTL-SDR w/ TCXO + Upconverter)
  • 10x NESDR XTR+ sets (a.k.a E4000 RTL-SDR Dongles)
  • 10x NESDR Nano 2+ sets (a.k.a R820T2 w/ TCXO RTL-SDR in small “nano” package)
  • 15x NESDR Nano 2 sets (a.k.a R820T2 RTL-SDR in small “nano” package)

To enter all you need to do is comment on their blog post (not ours!). Their competition runs from 24 January 2016 20:00 UTC to 31 January 2016 20:00 UTC.

nooelec_comp

Competition Winners Announced!

Firstly, thanks to all who entered our competition. We saw a huge response and learned a great deal about what the RTL-SDR community is up to these days. I encourage everyone to take a look through the comments on the competition post if you’re looking for project inspiration.

We ran competitions on Twitter, Facebook, the competition post itself and on our mailing list. We randomly chose 5 winners from each competition and will be sending them each one of our RTL-SDR Blog dongles. The 20 winners have now been selected. If you missed out, don’t worry – we hope to do more competitions like this again this year!

Facebook Winners!

Winners, please check your Facebook private messages. If you don’t see it, the message may be hidden in the spam inbox.

Zim Zimmerman – Currently working hard to overcome the NOISE related to living in an apartment complex in a Seattle suburb! TWO band pass filters; shielding via Al foil wrap and a directional antenna have helped. As hams say; “Good luck in the contest OM!” 73 K4IES

Sammy Truong – Exploring quickpass highway toll system.

Jimmy Vance – Just getting started with SDR dongles. For now will use them as general purpose receivers and spectrum analyzers

Amy Cstar – I’m a newbie and I’m hoping to use this to listen to the ISS 

Cezar Lesanu – Already running a radio meteor detection setup on RMOB and frequency stability and shielding are issues:http://www.rmob.org/livedata/main.php#Cezar Lesanu_ROAN@USV

Twitter Winners!

Winners, we’ve publicly tweeted you asking you to please email us directly. Please also tweet back at us confirming that you’ve received our notification.

Xizt ‏@RECEPTORR – Will use RTL-SDR dongle for learning wide band signals and monitoring Ham radio bands.

Rooster Mcdoogle ‏@RoosterMcdoogle – My first SDR project is going to be identifying/decoding local signals, and then satellites.

Sparkie Nelson ‏@SparkieNelson – Need a cheap spectrum analyzer for balloon beacon transmitter development.

DPini ‏@DPini – Right now, I’m trying to build a QFH antenna. My intention is to recieve NOAA and CubeSats

D M Miller ‏@bentmg – Hoping to set up a dedicated sdr to decode some DMR and NXDN signals in my area for streaming if I win the giveaway!

Blog Comment Winners!

We’ve emailed all blog comment winners using the email address that was provided. Please check your spam folder if you don’t see it, or contact us directly.

Jeff – Portable rf spectrum analysis

Stephen McBain – Starting out at the basics and using a dongle to decode different signals and just learning radio.

Matt – I’m working on building a WebSDR in Bucharest with full coverage from ~15mhz to ~1700mhz (R820T2 upper limit)

John Wilkerson – I use dual dongles for monitoring p25 trunked systems, as well as aircraft tracking.

Bryan – I’m pairing the RTL-SDR with my TS-940SAT and DXLab Commander + SDR# FTW.

Mailing List Winners! (Emails obscured for privacy)

We’ve obscured the winning emails for privacy, but we’ve emailed these winners now. Please check your spam inbox too!

g___e__e.r_i___i@____.com

j____p__a@____.com

v___o_t@________.ca

m_r___n@________.net

d_b___l_+_t_s_r@_____.com

Reverse Engineering Cheap Chinese Radio Firmware

This post isn’t related to SDR, however it may interest many readers as it has the potential to become the “RTL-SDR” of handheld hardware radios. Recently at Shmoocon 2016 (a yearly hacking and security themed conference), hardware hacker Travis Goodspeed showed how he was able to reverse engineer the firmware of a cheap Chinese made Tytera MD380 DMR digital handheld radio transceiver.

The reverse engineering feat essentially means that custom firmware can now be written to the radio. They’ve already managed to add a promiscuity mode that allows the radio to be able to receive from all talk groups on a known repeater and timeslot. Access to he firmware now also means that custom decoders for protocols such as P25, D-Star or System Fusion can potentially be added to the radio’s features in the future. In the end this could turn this cheap $140 radio into a more featured radio that would be worth much more.

See the full story over at Hackaday and the white paper here (start at page 76) and the video of the talk below.

Inside the Tytera MD380
Inside the Tytera MD380

SDRDX Now supports the RTL-SDR on OSX

SdrDx is a free software defined radio application that was originally written to support SDRs built by RF Space. However these days it appears to support multiple other SDRs including the Funcube, Andrus, Peaberry/Softrock and AFEDRI SDRs.

In the latest update they have also added support for the RTL-SDR on OSX. An RTL-SDR dongle is able to connect to the SdrDx program via a special OSX based RTL-SDR server called CocoaRTLServer. At the moment it appears that rtl_tcp is not supported as it does not use the protocol required by SdrDx, so Windows and Linux computers cannot use this software.

Compared to other general purpose SDR receiving software SdrDx has some interesting features not seen in most SDR software that supports the RTL-SDR. The full feature list and list of currently supports SDRs can be found here.

The SdrDX main screen.
The SdrDX main screen.

RTL-SDR.com SDR Dongle Giveaway!

We are giving away 20 of our new units with the metal case!

Competition has now ended! Thanks to all who entered! Winners to be announced by Monday.

The RTL-SDR and SDR community spans multiple disciplines and there are many wildly different projects being worked on by SDR enthusiasts as regular readers of our blog may already know. We want to thank all our readers with a competition and at the same time get everyone to share what projects you are all working on.

There are four chances to enter the contest and you may enter in all four competitions. On each method we will give away 5 RTL-SDR blog dongle + antenna units. Competition ends in one week on the 22nd of January at 23:59 hrs (midnight) PST time. Winners will be notified in the following 1-2 days and we will do a post about it too.

Competition Entry 1) Like us on Facebook and make a comment on the the contest post mentioning what SDR related projects you are currently working on, or plan to work on in the future.

Competition Entry 2) Follow us on Twitter and tweet at us @rtlsdrblog mentioning the SDR related projects you are currently working on, or plan to work on in the future.

Competition Entry 3) Make a comment on this very blog post mentioning what SDR related projects you are currently working on, or plan to work on in the future. (Please include a contact email address in the email field – it will only be visible to us and we won’t use it for anything else, promise!)

Competition Entry 4) Sign up to our email mailing list here or on the right hand navigation menu. (we send out a once weekly digest of the weeks posts).

 

We want to hear about any and all projects, no matter how simple you might think they are! At the end of the competition we will randomly select five winners from each competition entry method and contact them. Please remember to check your Facebook/Twitter/email accounts if your name comes up when the winners are announced.

Rules: Only one entry per person per method! E.g. you can enter once on Facebook, once on Twitter, once by commenting here, and once by signing up to our mailing list. No duplicate accounts are allowed. You must be legally be allowed to receive and own an RTL-SDR dongle to enter.

New RTL-SDR Dongles with Metal Case Available in our Store

Currently we at RTL-SDR.com are selling upgraded RTL-SDR dongles on our store. We’ve worked hard to reduce the most common issues that the cheapest generic dongles have, whilst trying to not significantly increase the retail price so that these devices stay ubiquitous. In each batch that we’ve produced so far we’ve tried to make some improvements over the last. Previously we’ve added a TCXO, SMA connector, and bias tee and now in the latest batch we’ve added a metal case and passive cooling.

The new units have been in stock at our Chinese warehouse for almost a month now, and they are now back in stock at Amazon USA as well (shipping soon). They are priced the same as before: $24.95 USD for the unit with antennas and $19.95 USD for the dongle only. If you order from the Chinese warehouse all units come with free registered air mail shipping (1-4 week delivery), and free shipping is available on Amazon for USA customers (<1 week delivery) if you are a Prime member or spend over $35.

To purchase please see our store page at www.rtl-sdr.com/store.

New features in this version:

  • Aluminium case. We’ve upgraded from a plastic case and now all units come with an aluminium case standard. The aluminium is 1mm thick and is treated with an anti-anodizing coating to improve conductivity. However, some natural anodization still occurs. The dimensions are similar to the plastic case at 69 mm x 27 mm x 13 mm.
The new RTL-SDR dongle design with aluminium case.
The new RTL-SDR dongle design with aluminium case.
  • Ground tracks on the PCB. The PCB size has been increased slightly to accommodate side ground tracks. These ground tracks should make contact with the aluminium and provide ground conductivity to the case.
New RTL-SDR PCB with side ground tracks.
New RTL-SDR PCB with side ground tracks.
  • Passive cooling. As the case is now metal we can apply a thermal interface material between the PCB bottom and case wall. The interface material we’ve chosen is a 3mm thermal pad. This is a soft silicon pad with high thermal conductivity. This appears to provide adequate cooling to ensure the dongles run properly at above 1.5 GHz.
Thermal pad on the bottom of the PCB for improved heat dissipation.
Thermal pad on the bottom of the PCB for improved heat dissipation.

The metal case and side ground tracks should reduce the amount of interference received by the dongle through sources other than the antenna. The passive cooling should also be enough to ensure that the dongles run properly at above 1.5 GHz, though we still would recommend running them in a cool shady place, rather than out in the direct sun if monitoring L-band signals. If you find that the conductivity between the PCB and case is not good enough, then you can try thickening the side ground tracks on the PCB with a layer of solder – we will be trying to increase the thickness by default in subsequent batches.

Soon we will also have the metal cases for sale by themselves for those who want to upgrade from a previous batch (EDIT: Now on sale!). Though please note that although the older SMA PCBs fit in this case, the previous batches PCB’s are a little smaller than what this case takes so it may fit a little loosely. The old PCB’s also don’t have the side ground tracks for improved conductivity, but even with no ground conductivity it is still possible for the case to work as a Faraday cage. These cases will be available on the store page in a few days at a very low cost and they will only be available only from the Chinese warehouse.

Once again we hope people will enjoy these changes, and feel free to let us know what you think and what you might like to see in the future.

SDRPlay RSP API Updated to Version 1.8.0

The SDRplay team have recently released a major update to their API and drivers. The new version is 1.8.0 and they write that it should remove the DC offset, reduce in band images from strong signals, and lower the noise floor. The SDRplay is a software defined receiver that costs $149 USD. They write:

We are pleased to announce release 1.8.0 of the API for the RSP. This is a major upgrade to the API with new features and an improved gain map which should result in improved performance over a key portion of the gain control range. Currently this API is available for Windows only, but versions for Linux and Mac OS and Android will follow shortly.

The API now incorporates automatic post tuner DC offset correction and I/Q compensation. This will almost completely eliminate the DC centre spike that was previously present in zero IF mode and also correct for amplitude and phase errors in the I/Q signal paths that can lead to in-band images when strong signals are present.

There is a new gain map for the RSP which should help improve the receiver noise floor for gain reduction settings in the range of 59-78 dB. To achieve this, the IF gain control range has been increased from 59 to 78 dB. In addition, the user can now turn the LNA on or off at any point within the IF gain control range. This means that the LNA can remain on for gain reduction settings of up to 78 dB, whereas previously the maximum gain reduction that could be attained whilst the LNA was on was only 59 dB. Being able to leave the LNA on will result in improvements in the receiver noise performance for gain reductions in the range of 59 to 78 dB. The upper 19 dB of the IF gain control range have now been disabled. In practice this part of the gain control range was useless as trying to operate within this region always lead to receiver overload even when signals were very weak.

To fully exploit the features of this new API release, we have also issued release 3.5 of the ExtIO plugin. This plugin will work with HDSDR, SDR sharp (releases 1361 or earlier) and Studio 1. Automatic I/Q compensation and DC offset correction will work with later versions of SDR sharp, but we will need to update the native plugin for users of these later versions to be access the new gain map.

Similarly, users of SDR Console will gain the benefit of automatic DC offset compensation and I/Q correction, but will not yet be able to access the new gain map. We hope that a version of SDR console that unlocks this feature will become available in the near future.

Until a new release of SDR-Console is available, you can copy the API into the SDR-Console installation directory…

from C:\Program Files\MiricsSDR\API\x64\mir_sdr_api.dll to C:\Program Files\SDR-RADIO-PRO.com\mir_sdr_api.dll

The API installer has also contains an extra certificate to be more user friendly for Windows XP, Vista and Windows 7 users.

The new API and ExtIO plugin can be downloaded from our website at:www.sdrplay.com/windows.html

As they write that in band images from strong signals are reduced in this version we decided to do a quick before and after test using our own RSP receiver. We tuned into some TETRA signals that had exhibited images in the past on our RSP (you can see them as the yellow signals in the before image). In the new driver the images are completely gone.

Meteor M-N1 Still Working, Meteor M-N2 Still Down

The Meteor M N-2 is a polar orbiting Russian weather satellite that was launched in July 2014. It transmits with the LRPT protocol which allows us to receive weather satellite images that are of a much higher resolution than the NOAA APT satellites. For a while since the launch RTL-SDR users had a good time receiving beautiful images from Meteor M-N2, but unfortunately since late last year the N2 LRPT transmitter has been turned off, due to technical problems with the IR sensors as cited by Russian meteorologists.

Fortunately for Meteor N2 enthusiasts the old Meteor M N1 satellite which was thought to be dead sprung back into life around November 2015. Recently Matthew A., a reader of our blog wrote in to let us know that while N2 is still not transmitting, N1 is still transmitting, albeit with somewhat distorted images. Matthew also mentions this link: http://homepage.ntlworld.com/phqfh1/status.htm, which contains up to date info on the status of all weather satellites. He also writes: 

  • While transmissions are readily detectable and decodable at night, it seems that M N-1’s infrared sensors are not functioning. Yielding only black, with the typical noise bars of Red, Green, or Blue
  • As has been previously mentioned, Meteor MN-1’s stabilization system has obviously failed, and the horizon is clearly visible. Perhaps not of scientific value, but certainly beautiful. 

We also note that there are several comments over on the Meteor-M N2 news and support website regarding receiving images from N1 and N2. It seems that sometimes N1 also has some problems with transmission, but they are usually quickly fixed.

Meteor M-N1 Image Received by Matthew
Meteor M-N1 Image Received by Matthew
 

Nooelec + AmateurRadio.com RTL-SDR Competition now Running

Hot on the tails of our own competition which has now closed, Nooelec and AmateurRadio.com have teamed up to create a giveaway for a HackRF One and 40 RTL-SDR dongles (some even bundled with upconverters)! They are giving away:

  • 1x HackRF One HF SDR Bundle (Includes upconverter and adapters)
  • 3x NESDR XTR+ HF bundles (a.k.a E4000 RTL-SDR + Upconverter)
  • 2x NESDR Mini 2+ HF bundles (a.k.a R820T2 RTL-SDR w/ TCXO + Upconverter)
  • 10x NESDR XTR+ sets (a.k.a E4000 RTL-SDR Dongles)
  • 10x NESDR Nano 2+ sets (a.k.a R820T2 w/ TCXO RTL-SDR in small “nano” package)
  • 15x NESDR Nano 2 sets (a.k.a R820T2 RTL-SDR in small “nano” package)

To enter all you need to do is comment on their blog post (not ours!). Their competition runs from 24 January 2016 20:00 UTC to 31 January 2016 20:00 UTC.

nooelec_comp

Competition Winners Announced!

Firstly, thanks to all who entered our competition. We saw a huge response and learned a great deal about what the RTL-SDR community is up to these days. I encourage everyone to take a look through the comments on the competition post if you’re looking for project inspiration.

We ran competitions on Twitter, Facebook, the competition post itself and on our mailing list. We randomly chose 5 winners from each competition and will be sending them each one of our RTL-SDR Blog dongles. The 20 winners have now been selected. If you missed out, don’t worry – we hope to do more competitions like this again this year!

Facebook Winners!

Winners, please check your Facebook private messages. If you don’t see it, the message may be hidden in the spam inbox.

Zim Zimmerman – Currently working hard to overcome the NOISE related to living in an apartment complex in a Seattle suburb! TWO band pass filters; shielding via Al foil wrap and a directional antenna have helped. As hams say; “Good luck in the contest OM!” 73 K4IES

Sammy Truong – Exploring quickpass highway toll system.

Jimmy Vance – Just getting started with SDR dongles. For now will use them as general purpose receivers and spectrum analyzers

Amy Cstar – I’m a newbie and I’m hoping to use this to listen to the ISS 

Cezar Lesanu – Already running a radio meteor detection setup on RMOB and frequency stability and shielding are issues:http://www.rmob.org/livedata/main.php#Cezar Lesanu_ROAN@USV

Twitter Winners!

Winners, we’ve publicly tweeted you asking you to please email us directly. Please also tweet back at us confirming that you’ve received our notification.

Xizt ‏@RECEPTORR – Will use RTL-SDR dongle for learning wide band signals and monitoring Ham radio bands.

Rooster Mcdoogle ‏@RoosterMcdoogle – My first SDR project is going to be identifying/decoding local signals, and then satellites.

Sparkie Nelson ‏@SparkieNelson – Need a cheap spectrum analyzer for balloon beacon transmitter development.

DPini ‏@DPini – Right now, I’m trying to build a QFH antenna. My intention is to recieve NOAA and CubeSats

D M Miller ‏@bentmg – Hoping to set up a dedicated sdr to decode some DMR and NXDN signals in my area for streaming if I win the giveaway!

Blog Comment Winners!

We’ve emailed all blog comment winners using the email address that was provided. Please check your spam folder if you don’t see it, or contact us directly.

Jeff – Portable rf spectrum analysis

Stephen McBain – Starting out at the basics and using a dongle to decode different signals and just learning radio.

Matt – I’m working on building a WebSDR in Bucharest with full coverage from ~15mhz to ~1700mhz (R820T2 upper limit)

John Wilkerson – I use dual dongles for monitoring p25 trunked systems, as well as aircraft tracking.

Bryan – I’m pairing the RTL-SDR with my TS-940SAT and DXLab Commander + SDR# FTW.

Mailing List Winners! (Emails obscured for privacy)

We’ve obscured the winning emails for privacy, but we’ve emailed these winners now. Please check your spam inbox too!

g___e__e.r_i___i@____.com

j____p__a@____.com

v___o_t@________.ca

m_r___n@________.net

d_b___l_+_t_s_r@_____.com

Reverse Engineering Cheap Chinese Radio Firmware

This post isn’t related to SDR, however it may interest many readers as it has the potential to become the “RTL-SDR” of handheld hardware radios. Recently at Shmoocon 2016 (a yearly hacking and security themed conference), hardware hacker Travis Goodspeed showed how he was able to reverse engineer the firmware of a cheap Chinese made Tytera MD380 DMR digital handheld radio transceiver.

The reverse engineering feat essentially means that custom firmware can now be written to the radio. They’ve already managed to add a promiscuity mode that allows the radio to be able to receive from all talk groups on a known repeater and timeslot. Access to he firmware now also means that custom decoders for protocols such as P25, D-Star or System Fusion can potentially be added to the radio’s features in the future. In the end this could turn this cheap $140 radio into a more featured radio that would be worth much more.

See the full story over at Hackaday and the white paper here (start at page 76) and the video of the talk below.

Inside the Tytera MD380
Inside the Tytera MD380

SDRDX Now supports the RTL-SDR on OSX

SdrDx is a free software defined radio application that was originally written to support SDRs built by RF Space. However these days it appears to support multiple other SDRs including the Funcube, Andrus, Peaberry/Softrock and AFEDRI SDRs.

In the latest update they have also added support for the RTL-SDR on OSX. An RTL-SDR dongle is able to connect to the SdrDx program via a special OSX based RTL-SDR server called CocoaRTLServer. At the moment it appears that rtl_tcp is not supported as it does not use the protocol required by SdrDx, so Windows and Linux computers cannot use this software.

Compared to other general purpose SDR receiving software SdrDx has some interesting features not seen in most SDR software that supports the RTL-SDR. The full feature list and list of currently supports SDRs can be found here.

The SdrDX main screen.
The SdrDX main screen.

RTL-SDR.com SDR Dongle Giveaway!

We are giving away 20 of our new units with the metal case!

Competition has now ended! Thanks to all who entered! Winners to be announced by Monday.

The RTL-SDR and SDR community spans multiple disciplines and there are many wildly different projects being worked on by SDR enthusiasts as regular readers of our blog may already know. We want to thank all our readers with a competition and at the same time get everyone to share what projects you are all working on.

There are four chances to enter the contest and you may enter in all four competitions. On each method we will give away 5 RTL-SDR blog dongle + antenna units. Competition ends in one week on the 22nd of January at 23:59 hrs (midnight) PST time. Winners will be notified in the following 1-2 days and we will do a post about it too.

Competition Entry 1) Like us on Facebook and make a comment on the the contest post mentioning what SDR related projects you are currently working on, or plan to work on in the future.

Competition Entry 2) Follow us on Twitter and tweet at us @rtlsdrblog mentioning the SDR related projects you are currently working on, or plan to work on in the future.

Competition Entry 3) Make a comment on this very blog post mentioning what SDR related projects you are currently working on, or plan to work on in the future. (Please include a contact email address in the email field – it will only be visible to us and we won’t use it for anything else, promise!)

Competition Entry 4) Sign up to our email mailing list here or on the right hand navigation menu. (we send out a once weekly digest of the weeks posts).

 

We want to hear about any and all projects, no matter how simple you might think they are! At the end of the competition we will randomly select five winners from each competition entry method and contact them. Please remember to check your Facebook/Twitter/email accounts if your name comes up when the winners are announced.

Rules: Only one entry per person per method! E.g. you can enter once on Facebook, once on Twitter, once by commenting here, and once by signing up to our mailing list. No duplicate accounts are allowed. You must be legally be allowed to receive and own an RTL-SDR dongle to enter.

New RTL-SDR Dongles with Metal Case Available in our Store

Currently we at RTL-SDR.com are selling upgraded RTL-SDR dongles on our store. We’ve worked hard to reduce the most common issues that the cheapest generic dongles have, whilst trying to not significantly increase the retail price so that these devices stay ubiquitous. In each batch that we’ve produced so far we’ve tried to make some improvements over the last. Previously we’ve added a TCXO, SMA connector, and bias tee and now in the latest batch we’ve added a metal case and passive cooling.

The new units have been in stock at our Chinese warehouse for almost a month now, and they are now back in stock at Amazon USA as well (shipping soon). They are priced the same as before: $24.95 USD for the unit with antennas and $19.95 USD for the dongle only. If you order from the Chinese warehouse all units come with free registered air mail shipping (1-4 week delivery), and free shipping is available on Amazon for USA customers (<1 week delivery) if you are a Prime member or spend over $35.

To purchase please see our store page at www.rtl-sdr.com/store.

New features in this version:

  • Aluminium case. We’ve upgraded from a plastic case and now all units come with an aluminium case standard. The aluminium is 1mm thick and is treated with an anti-anodizing coating to improve conductivity. However, some natural anodization still occurs. The dimensions are similar to the plastic case at 69 mm x 27 mm x 13 mm.
The new RTL-SDR dongle design with aluminium case.
The new RTL-SDR dongle design with aluminium case.
  • Ground tracks on the PCB. The PCB size has been increased slightly to accommodate side ground tracks. These ground tracks should make contact with the aluminium and provide ground conductivity to the case.
New RTL-SDR PCB with side ground tracks.
New RTL-SDR PCB with side ground tracks.
  • Passive cooling. As the case is now metal we can apply a thermal interface material between the PCB bottom and case wall. The interface material we’ve chosen is a 3mm thermal pad. This is a soft silicon pad with high thermal conductivity. This appears to provide adequate cooling to ensure the dongles run properly at above 1.5 GHz.
Thermal pad on the bottom of the PCB for improved heat dissipation.
Thermal pad on the bottom of the PCB for improved heat dissipation.

The metal case and side ground tracks should reduce the amount of interference received by the dongle through sources other than the antenna. The passive cooling should also be enough to ensure that the dongles run properly at above 1.5 GHz, though we still would recommend running them in a cool shady place, rather than out in the direct sun if monitoring L-band signals. If you find that the conductivity between the PCB and case is not good enough, then you can try thickening the side ground tracks on the PCB with a layer of solder – we will be trying to increase the thickness by default in subsequent batches.

Soon we will also have the metal cases for sale by themselves for those who want to upgrade from a previous batch (EDIT: Now on sale!). Though please note that although the older SMA PCBs fit in this case, the previous batches PCB’s are a little smaller than what this case takes so it may fit a little loosely. The old PCB’s also don’t have the side ground tracks for improved conductivity, but even with no ground conductivity it is still possible for the case to work as a Faraday cage. These cases will be available on the store page in a few days at a very low cost and they will only be available only from the Chinese warehouse.

Once again we hope people will enjoy these changes, and feel free to let us know what you think and what you might like to see in the future.

SDRPlay RSP API Updated to Version 1.8.0

The SDRplay team have recently released a major update to their API and drivers. The new version is 1.8.0 and they write that it should remove the DC offset, reduce in band images from strong signals, and lower the noise floor. The SDRplay is a software defined receiver that costs $149 USD. They write:

We are pleased to announce release 1.8.0 of the API for the RSP. This is a major upgrade to the API with new features and an improved gain map which should result in improved performance over a key portion of the gain control range. Currently this API is available for Windows only, but versions for Linux and Mac OS and Android will follow shortly.

The API now incorporates automatic post tuner DC offset correction and I/Q compensation. This will almost completely eliminate the DC centre spike that was previously present in zero IF mode and also correct for amplitude and phase errors in the I/Q signal paths that can lead to in-band images when strong signals are present.

There is a new gain map for the RSP which should help improve the receiver noise floor for gain reduction settings in the range of 59-78 dB. To achieve this, the IF gain control range has been increased from 59 to 78 dB. In addition, the user can now turn the LNA on or off at any point within the IF gain control range. This means that the LNA can remain on for gain reduction settings of up to 78 dB, whereas previously the maximum gain reduction that could be attained whilst the LNA was on was only 59 dB. Being able to leave the LNA on will result in improvements in the receiver noise performance for gain reductions in the range of 59 to 78 dB. The upper 19 dB of the IF gain control range have now been disabled. In practice this part of the gain control range was useless as trying to operate within this region always lead to receiver overload even when signals were very weak.

To fully exploit the features of this new API release, we have also issued release 3.5 of the ExtIO plugin. This plugin will work with HDSDR, SDR sharp (releases 1361 or earlier) and Studio 1. Automatic I/Q compensation and DC offset correction will work with later versions of SDR sharp, but we will need to update the native plugin for users of these later versions to be access the new gain map.

Similarly, users of SDR Console will gain the benefit of automatic DC offset compensation and I/Q correction, but will not yet be able to access the new gain map. We hope that a version of SDR console that unlocks this feature will become available in the near future.

Until a new release of SDR-Console is available, you can copy the API into the SDR-Console installation directory…

from C:\Program Files\MiricsSDR\API\x64\mir_sdr_api.dll to C:\Program Files\SDR-RADIO-PRO.com\mir_sdr_api.dll

The API installer has also contains an extra certificate to be more user friendly for Windows XP, Vista and Windows 7 users.

The new API and ExtIO plugin can be downloaded from our website at:www.sdrplay.com/windows.html

As they write that in band images from strong signals are reduced in this version we decided to do a quick before and after test using our own RSP receiver. We tuned into some TETRA signals that had exhibited images in the past on our RSP (you can see them as the yellow signals in the before image). In the new driver the images are completely gone.