• Hello all,


    I've got my both 0.5ppm RTL-SDR dongles from China but compared to my AirSpy they seem to be quite insensitive. When I turn my LNB power on/off (or when I unplug the AirSpy) I see a huge noise floor coming up. Nothing like that with the new RTL-SDR's.. also the EB is much weaker.. I think there is some 20dB or so missing? Or do I miss a gain setting somewhere in the RTL-SDR configuration?


  • I use the same RTL SDR sticks and never encountered such problems.

    When i shut off the LNB voltage the noisefloor drops as expected.

    For the RX sensitivity i can only say with an 130cm offset dish pointed at 26° after 20m cable the (lower) EB is at 39-40dB over noise.


    73 DB8TF

  • Yes, when you first use RTL-SDR sticks in software you should search for the gain setting that can be set to something between 0 and 50dB or "automatic" and make sure it is either on "automatic" or you change the setting to something reasonable for your setup. Try 20dB or so.

  • Hi Lucio,

    I have not made any real measurements with Lab equipment, but I must say I'm very impressed by this NEWGEN.RTL2832SDR in particular for that price. At least behind the LNB for P4-A usage it seems to be ideal and for SSB no need to worry about modifying the LNB's (with PLL).... I may try some VHF reception later and compare it with my Funcube Dongle..

    pe1chl no Serial numbers on my NEWGEN-RTL-SDR's ;-)

  • pe1chl no Serial numbers on my NEWGEN-RTL-SDR's ;-)

    RTL-SDR sticks have an electronically readable serial number. On most if not all devices I have seen the number is 00000001 :-)

    (also on those NEWGEN-RTL-SDR sticks that I recently ordered)

    So even more exclusive than your Funcube dongle :-)

    But you can change it. E.g. on Linux do this (with a single stick plugged in):

    rtl_eeprom -d 0 -s 12345678

    You will see the current serial number and the proposed new one, and answer y to the question if you want to write it.

    Then unplug and re-insert the stick and it will be serial number 12345678 now.

    When you have several sticks you can use this to know which one you are accessing in your program (at least when it supports the serial number).

  • RTL-SDR sticks have an electronically readable serial number. On most if not all devices I have seen the number is 00000001 :-)

    Well, here is the proof that my FCD has a real Serial number.. ;-)

    I was lucky many years ago on the AMSAT-UK Symposium Dinner Tombola.. :-)