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John subs at qcontinuum.plus.comHello, I am new to this list and to SDR radio. I have purchased an SDR dongle but am having trougble getting it to work. The dongle was described as an RTL8232U/R820T2 device. I am running on Linux MINT version 18.2 and lsusb detects the device as follows: Bus 002 Device 051: ID 0bda:2838 Realtek Semiconductor Corp. RTL2838 DVB-T Is it an RTL2832U or an RTL2838? I'm not really sure. From research it seems that It seems like the fist order of business is to blacklist the kernel driver? So I have done this by adding a backlist-rtl.conf file to /etc/modprobe.d and rebooted the computer. I have also added a rules file to /etc/udev/rules.d with the following content: # Realtek Semiconductor Corp. RTL2838 DVB-T SUBSYSTEMS=="usb", ATTRS{idVendor}=="0bda", ATTRS{idProduct}=="2838", MODE:="0666", GROUP="adm", SYMLINK+="rtl_sdr" I can now access the device in user mode without permission errors so I assume that this is working OK. So my next step was to run rtl_test -t. The output I got contained errors.If I then try to run any sdr software such as rtl_fm or gqrx, the device is reset and the application fails to run. Subsequentlly running 'rtl_test -t' gives: No supported devices found. Even running rtl_test-t sometimes does the same so i'm not sure whether the device is 'dropping out' of its own accord. I am wondering whether the current crop of devices are supported? Or is this a configuration problem? The output from rtl_test: rtl_test -t Found 1 device(s): 0: Realtek, RTL2838UHIDIR, SN: 00000001 Using device 0: Generic RTL2832U OEM Found Rafael Micro R820T tuner r82xx_write: i2c wr failed=-1 reg=13 len=7 r82xx_write: i2c wr failed=-1 reg=0c len=1 r82xx_init: failed=-1 rtlsdr_demod_write_reg failed with -1 rtlsdr_demod_read_reg failed with -1 Supported gain values (29): 0.0 0.9 1.4 2.7 3.7 7.7 8.7 12.5 14.4 15.7 16.6 19.7 20.7 22.9 25.4 28.0 29.7 32.8 33.8 36.4 37.2 38.6 40.2 42.1 43.4 43.9 44.5 48.0 49.6 rtlsdr_demod_write_reg failed with -1 rtlsdr_demod_read_reg failed with -1 r82xx_write: i2c wr failed=-1 reg=0a len=1 rtlsdr_demod_write_reg failed with -1 rtlsdr_demod_read_reg failed with -1 rtlsdr_demod_write_reg failed with -1 rtlsdr_demod_read_reg failed with -1 rtlsdr_demod_write_reg failed with -1 rtlsdr_demod_read_reg failed with -1 rtlsdr_demod_write_reg failed with -1 rtlsdr_demod_read_reg failed with -1 rtlsdr_demod_write_reg failed with -1 rtlsdr_demod_read_reg failed with -1 rtlsdr_demod_write_reg failed with -1 rtlsdr_demod_read_reg failed with -1 rtlsdr_demod_write_reg failed with -1 rtlsdr_demod_read_reg failed with -1 WARNING: Failed to set sample rate. No E4000 tuner found, aborting. rtlsdr_demod_write_reg failed with -1 rtlsdr_demod_read_reg failed with -1 rtlsdr_demod_write_reg failed with -1 rtlsdr_demod_read_reg failed with -1 rtlsdr_write_reg failed with -1 -- John