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SDR Using R820T based USB TV Dongles

From the Microwave Mailing List at http://lists.valinet.com/cgi-bin/mailman/listinfo/microwave on Jan 5, 2013

I installed the supplied software to take a look but I am out in the boonies so hoping to see a HDTV channel with the indoor antenna supplied was dreaming. But it did serve to check out the hardware was responding.

I downloaded latest nightly build of SDR# (1.0.0.1110) following the instructions at the link for Windows below (run install program) and then ran Zadig to install the driver. I initially had a rough time after tuning and toggling Play and Stop, got “Cannot access RTL device” messages. I moved it around different USB ports, reboot a few times, reinstalled a few times, finally it is operating well for hours now.

This is the Windows instructions I used. http://rtlsdr.org/softwarewindows

In Zadig, instead of Bulk IN and Bulk Out device info you want to select the RTL2838UHIDIR device. In SDR# it will be the RTL-SDR/USB device. If you select the “Other sound card” device in SDR# you should hear your PC's microphone in your PC's speakers. and see the spectrum display OK as a quick test.

I found that on my newer (ie fast) Windows 8 x64 machine I can run the max sample rate of 3.2 just fine.

There are a few forums that talk to SDR and the RTL device topics. Here are a few links that I used tonight.
http://uk.groups.yahoo.com/group/SDRSharp/
https://groups.google.com/forum/#!forum/ultra-cheap-sdr
http://sdrsharp.com/downloads/sdr-install.zip

Since I did not have a MCX connector I cut the supplied antenna cable and crimped on a RG174 size BNC connector. I experimented with it on my frequency counter to check the sensitivity and noise floor, that is what drove me to discover the RF gain control. I had to pump a lot of signal in to budge the display since the default has it cranked way down. Put it on the transverter stack RX out and seems to work fine, both on 144 and 28MHz IF.

There is a shift setting that I had to enable with values around 13,000 to 14,500 to calibrate the displayed frequency. In the configure there is a correction factor that I have not set yet. I also found that enabling Correct IQ removed an image signal. I have not RTM yet so this is just the quick stuff I hit tonight.

On the FrequencyManager/Scanner topic, see https://groups.google.com/forum/#!topic/ultra-cheap-sdr/YQsZQt_dujM
It links to downloads and a PDF user guide. I looks like it requires a newer built than the 1110 I found tonight.

I tried it anyway and the plugin showed up, I can enter data and sort of get it working, but definitely not the right version match so I backed it out.

One important detail I found after some time was that you can open the Configure dialog while it is running and turn on and off the Tuner AGC and RTL AGC controls, and if allowed, manually set the RF gain over a wide range. I found that manual setting was best for me. Then I adjusted the FFT Display Offset and Range controls for best display, also tweaked the contrast at times.

I have my 2M 10el yagi antenna (with tower preamp) connected and listening to public safety and ham bands just fine.

There is a Frequency Manager plug In that I have put to good use for my favorite Public Safety, NOAA and Ham band frequencies. You can place them into groups and more. I think it is supposed to be able to scan but have not figured that out yet. Selecting a different group will re-sort the list after you add new items.

Hope this helps some.

73,

Mike Lewis
K7MDL
Grid Locator CN87xt
Member of Pacific Northwest VHF Society #C96 (www.pnwvhfs.org) Elecraft K3 #6031

 
ham_radio/sdr_using_r820t_based_usb_tv_dongles.txt · Last modified: 2013/01/08 19:00 (external edit)
 
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