Tagged: rtl2832u

Getting SDR# and RTL-SDR to run on OSX El Capitan with Mono

A few weeks ago Matthew Miller showed us how it was possible to run DSD+ in OSX using a program called Wineskin. Now he’s uploaded a new video that shows how to get SDR# working in OSX El Capitan with Mono. SDR# is designed to be used in Windows, but since it is written in C# under the .NET framework, it should be possible to run it on OSX with the open source Mono .NET implementation. The overall installation is not as straight forward as simply downloading a zip file like it is on Windows, but the tutorial Matthew provides is clear and easy to follow.

The steps involve downloading SDR#, downloading Mono, installing MacPorts, installing PortAudi, installing the RTL-SDR libraries and then setting up some required symbolic links. Finally he shows that to access the RTL-SDR you must first run RTL-TCP and then connect to that using the RTL-SDR (TCP) option in SDR#.

SDR# on MAC OSX EL CAPITAN - RTL SDR - MONO

RTLSDR4Everyone: Review of 5 RTL-SDR Dongles

Over on the rtlsdr4everyone blog (previously known as the sdr4mariners blog), author Akos has uploaded a new post that compares 5 different RTL-SDR dongles against one another. He compares a Terratec R820T, Black Nooelec R820T, Blue Nooelec R820T2, our own RTL-SDR Blog R820T2 and a Nooelec Nano R820T.

In the post Akos gives an overview of the features of each dongle, and runs tests on things like frequency drift and broadcast FM interference. He also runs SNR tests on Airband, low UHF, high UHF signals and shortwave frequencies. His tests show that the dongles with the R820T2 chip outperform the dongles with the R820T chip by about 4-5 dBs in SNR, and that the overall best dongle is our RTL-SDR Blog dongle.

In the future Akos hopes to also review the Nooelec 9:1 balun.

dongles_all
The dongles compared in Akos’ Review

 

Building a Wideband Helix Antenna for L/S/C Bands

Over on YouTube user Adam Alicajic (creator of the popular LNA4ALL low noise amplifier) has uploaded a video showing the performance of a home made wideband helix antenna that he has created for receiving signals such as ones from L-Band Inmarsat satellites. See our tutorial for more information on receiving Inmarsat signals.

Adams helix antenna is built out of an old used can and is based on a 1.1 turn design. In the first of three videos he shows that the SWR of the antenna is all well below 2.0 from 1.5 GHz to 3 GHz. In the second video Adam shows the performance of the helix antenna on actual L-band signals being received with an RTL-SDR dongle. In the final video Adam compares the helix again a patch antenna and finds that the two receive with very similar performance.

Wideband L/S/C band helix antenna Part.1

Wideband L/S/C band helix antenna Part.2

Wideband L/S/C band helix antenna Part.3

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
 

Enclosing two RTL-SDRs in a metal box to reduce noise

Over on his blog, Twitch has uploaded a post showing how he mounted two RTL-SDR dongles into a single metal case in order to reduce noise. Twitch used a $2 aluminium metal case that he obtained from a local surplus shop and cut it down to size and added holes for switches and BNC plugs. He then mounted two RTL-SDR dongles in the case and used two MCX -> BNC pigtails to get a case mounted coax connector.

He also removed the USB plugs on the RTL-SDR’s and wired them into a USB B plug mounted to the case, making sure to wind the USB power cables through several turns of ferrite core in order to reduce USB noise. Finally he also added a power switch to the USB connections, to be able to easily power off the units when not in use.

rtl_sdr_case
The two RTL-SDR’s placed into a aluminium case.

New Version of the Frequency Manager Suite Plugin for SDR# Released

Recently the commonly used Frequency Manager Suite Plugin for SDR# has been updated. The plugin suite works well with the RTL-SDR and includes features such as a frequency scanner and manager, a scanner metrics recorder, a scheduler, an activity logger and a frequency entry plugin. The changelog is shown below:

Frequency Manager + Scanner

  • New feature: you may now optionally display the descriptions of frequencies in your database on the spectrum window. You control the colors and transparency of the descriptions and their marker lines. 
  • New feature: the Browse window now allows you to type a frequency directly into the grid, and the grid will dynamically filter your database to matching frequencies. You may type a partial frequency and all frequencies that start with the same digits will be displayed. The more digits you type, the more specific the filtering.
  • New feature: A checkbox in Preferences lets you control whether the Last Update field is changed when performing bulk edits. When unchecked this permits you to retain the original date and time the frequency was recorded in the database. 
  • New feature: You may now change the font size in the Scanner Decisions window and plugin. The new size will be remembered and used the next time you start SDR#. 
  • New article:  User David Bunyan has provided a how-to article in the Appendix on how to use the scanner effectively for WFM DXing.  See also the WFM DXing Databases download in the Download Here section to get pre-built databases for different regions around the world, also graciously provided by David Bunyan.

Scanner Metrics

  • Bug fix: fixed error in the queue manager that prevented recording activity when the date-time format on the computer was not United States. 
  • Bug fix: fixed error that prevented SM from putting its database in the same folder as FM, if the FM database location was changed after SM was loaded.

Data Tools

  • New feature: default values for imports. Will automatically assign values when they are missing from the source import data.
  • Bug fix: Fixed culture-specific issue with Frequency values when an Eibi database is downloaded. 
  • Bug fix: Fixed bug that caused Data Tools to change the current database in Frequency Manager + Scanner. 
  • Bug fix: Importing an SDR# Frequency Manager data file now results in a prompt to add or replace existing data in the target FMSuite database.

The Pluginator

  • New feature: The Pluginator now knows many of the most popular plugins. So now you may simply select one from a list and it will be installed to Plugins.xml, as opposed to requiring you to type the configuration data for the chosen plugin.

FreqMgr

 

Using AIS Share, OpenCPN and an RTL-SDR on a Sailboat

AIS Share is an app for Android that allows you to turn an Android device into an AIS receiver by using an RTL-SDR. AIS stands for Automatic Identification System and is used by ships to broadcast their GPS locations, to help avoid collisions and aid with rescues. An RTL-SDR with the right software can be used to receive and decode these signals, and plot ship positions on a map.

AIS Share is a dual channel decoder that outputs decoded NMEA messages via UDP, so that plotting software like OpenCPN can be used to display the ships on a map. AIS Share had been around before in another form known as rtl_ais_android which we posted before, but this version of AIS Share is a newly updated and improved version that now includes a very nice GUI. The app costs about $2 and is available on the Google Play store, but there is a demo available that will work up until 1000 messages are received. You will need an RTL-SDR and a USB OTG cable to run the app.

Recently the author of the app received word from a user called Harmen who has successfully been using his AIS Share app on his sailboat. Harmen uses the app on an Android tablet which is enclosed in a waterproof box. For an antenna he uses a coax collinear.

In the future the author writes that he’d like to update the app to support things like the ability to change more dongle settings like bandwidth/sample rate and add the possibility of using the internal phone/tablet GPS. He is also open to any community suggestions.

AIS Share Receiver on the sailboat in a waterproof case.
AIS Share Receiver on the sailboat in a waterproof case.
The back of the Android Tablet, showing the RTL-SDR and the antenna connection.
The back of the Android Tablet, showing the RTL-SDR and the antenna connection.
The AIS Share main screen GUI.
The AIS Share main screen GUI.

https://www.youtube.com/watch?v=ApGk8P82THs (Unfortunately the video has been removed)

Testing a frequency synthesizer with an RTL-SDR

Harris Butler is designing his own software defined radio out of a Cypress PSOC5 (processor and ADC), an RF mixer, LNA and a frequency synthesizer (for use as a local oscillator) all purchased from eBay. Recently he wrote in to let us know that he had been testing the Frequency Synthesizer that he purchased and wanted to share his results.

When testing the frequency synthesizer Harris found that it could be fairly well calibrated to sit on a desired local oscillator frequency. Originally he had been testing the generator with it directly connected to the RTL-SDR, however later he added some attenuation to prevent the RTL-SDR from overloading. Despite this even with the attenuation he found that the frequency generator seemed to be fairly noisy and poor in terms of the strength of the harmonics produced. He notes that to use in a real application it will probably require good filtering.

In the video shown below Harris demonstrates the frequency generator output and harmonics using the RTL-SDR.

freq_harmonic