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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.


        • #94
          The FR24 feed is going great. I need to get on the roof to swap my antenna over from the scanner, which does a good job, to installing my little 4 leg spider I built to see if any better. I then will play about with other suggestions made here. Though last week, I got a message from FR24 saying my feed had stopped!! I pulled the power cable and rebooted and all well again.

          Question. Today, we get the NBN internet system, which replaces our old cable type. Anyway...the replacement modem and router may change the IP address I have setup for the Raspberry Pi in the FR24 feed. How do I change the FR24 feed to the revised IP address?

          LATER NOTE:...Turns out I did not need to do anything. When I installed the new Router/modem, it retained all the same IP settings and FR24 still working.
          Last edited by POR911; 2019-11-29, 07:47. Reason: Found the answer out.


          • #95
            Normally you just use in the fr24feed.ini (which is an address for "this computer").


            • #96
              Thanks wiedehopf, that is what must have happened. The internet swap over went very smoothly....very unusual for here. Hopefully, I can try my 4 leg spider on the roof in the next few weeks and compare with discone.