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Start of my RPi journey

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  • #91
    The rtl-sdr LNA has filters integrated, no need for extra filtering.

    Power is supplied via the coax. (bias-t)

    They even link a bias-t on their product page:

    Alternatively you can buy a dongle that has an internal bias-t to supply 5 V to the coax.
    (rtl-sdr v3 dongle, activated via software. nooelec nesdr smartee, always on)

    If you go the way of an external bias-t i'd recommend putting a 10 Ohm resistor in series, makes the LNA run a lot cooler.
    It should be fine running hot, but i was experimenting and it performance is fine at 3.3 V
    Last edited by wiedehopf; 2019-10-21, 05:57.


    • #92
      Thanks wiedehopf, as I already have a dongle, it seems easier to get the rtl-sdr LNA then link the bias-t to the coax near my RPi, where I can keep an eye on it. As I am not into radio kits etc, finding and soldering a 10 Ohm resistor in series is way above my skill grade. Thanks for your help, much appreciated.


      • #93
        Well you connect the external bias-t to wires anyway.
        (granted you can buy some that take a USB cable input)

        One of the wires you instead connect to the resistor and other end of the resistor to the bias-t.
        It's not exactly rocket science.

        Anyway you can use the 5V off the RPi to power the bias-t.