Mods and Performance of an R820T2 RTL-SDR

Over on his blog, RTL-SDR experimenter Laidukas had added a post showing how he modded his R820T2 RTL-SDR for improved noise performance. The mods he applies are:

  • Addition of 100nF, 1nF and 100pF bypass capacitors on the power supply rail.
  • Added a common mode choke to the 5V line.
  • Added a MuRata NFM21 EMI suppression filter to the 5V line.
  • Replaced the oscillator with a 0.3 ppm temperature controlled oscillator (TCXO).
  • Disabled the internal RTL2832U 1.2V switching supply and provided external 3.3V and 1.2V supplies.
  • Replaced the MCX connector with an SMA female connector.
  • Enclosed circuit in a metal box.
Modded R820T2 RTL-SDR Dongle
Modded R820T2 RTL-SDR Dongle

In addition to the mods, Laidukas also made some measurements on the performance of the R820T2 on some metrics. In the first test he measured the input insertion loss or SWR. He found that the SWR was below 2 between frequencies of 25 MHz to 1076 MHz. At higher frequencies the SWR reached levels up to about 8.

Another test showed that with the LNA disabled the R820T2 had a lower noise floor by about 7dB, when compared to the R820T.

SWR Plot of the RTL-SDR Antenna Input
SWR Plot of the RTL-SDR Antenna Input with LNA disabled

5 comments

  1. Laidukas

    Hi, short note to admin. I see that article is written referring to R820T2 tuner but in the front of article link is to my previous post about R820T.

    P.S. I added some additional info at the end of R820T2 post.

  2. KC3EDW

    Skip, Just curious what you mean by ‘November’ R820T2? Do you mean the nooelec version? Just curious because I have been using the Nooelec version with just the little whip that came with it for the past month or so plus I’m down in a valley and I am picking up around 300 flights a day give or take.

    Just curious if I’d have better results with the RTLSDR branded one.

    • Skip Flem

      I’d replace that antenna. I’m using 8 section colinear antennas, made from RG/6, with a ‘1 to 2 GHz’ inline Satellite pre-amp and ‘power injector’ from Amazon. (about $15) And you’ll
      need a 12V power supply, too. RTL-SDR also has a ‘T2 package with BETTER antennas (at least the coax has improved.) Yes, November refers to the baby blue nooelec unit. Also consider getting a Nooelec CASE, if you haven’t already.

  3. Skip Flem

    I just replaced my ‘November’ R820T2 with a RTL-SDR R820T2 I just got.
    I use it to track aircraft with Dump1090. NOW I’m getting 2X the planes
    with the ‘NEW’ RTL-SDR R820T2. 1,127 vs. 513 yesterday. 605 planes a day
    had been my previous ‘record’.

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