ThumbNet Special RTL-SDR For Sale: TCXO, Type F Connector, R820T2


Only $39.95 USD plus shipping ($7.4 USA incl. taxes, $10 international). Click add to cart to begin ordering. Shipping will be added at checkout.


If you missed out stay tuned, as we will have something similar for sale by the end of August. Sign up to our mailing list to be notified when the new units are for sale.

We have very limited quantities of surplus ThumbNet RTL-SDR dongles to sell. These RTL-SDR’s are significantly improved over the standard model, yet sell for a lower cost compared to other similar offerings. They have the following features:

  • A 1 PPM Temperature Compensated Oscillator (TCXO). Near perfect frequency offset and very low drift due to temperature.
  • Type-F antenna connector. Much sturdier and more common than the MCX connector used on most dongles.
  • Uses the R820T2 tuner chip. Improved sensitivity over the standard R820T.

In addition to receiving a high quality TCXO RTL-SDR for a price lower than any similar offering on the market at the moment, you’ll feel good knowing that you are also supporting an educational organisation which is helping to engage students in technology and the sciences.

Why are we selling these?

The ThumbNet educational project required a high quality custom RTL-SDR dongle to give out to students. In order to produce a custom model like this they had to order very large quantities from the factory – about double what they actually needed. We are simply helping them sell off the unneeded surplus and we expect stock to last until about mid year. Note that apart from helping them provide a cart which links to their PayPal account, is not affiliated with the ThumbNet project apart from a very small commission that will directly support this site.


All orders will be shipped by ThumbNet who are based in the USA. Orders will be shipped out in a padded envelope within 2 business days. 

Domestic orders should be received within 7 business days from time of order, usually faster. For international orders delivery times will vary but they should arrive within 2-4 weeks (usually less, but possibly longer for some remote countries) depending on any customs or postage delays in your country. If you don’t receive your order within these time frames please contact


ThumbSat is offering six months warranty against manufacturing defects on these dongles.

If you have any queries about faults or problems with the ThumbNet receivers you can contact

Larger Orders

If you wish to order over 25 units please email and ask for a quote.




  1. Tony

    Nice stable improvement over the standard RTL….1 to 2 S points. Mounted the unit in a home made brass box
    and soldered a short length of small coax from the F connector internal mount to a female case mount SMA. Now I have to inputs to choose from,The F and SMA. Also used a PGA103 preamp kit on the input (vhf/uhf from minikits Australia) Set the RTL2 gain in HDSDR from 40 down to 15 with the preamp on and this improves reception even better again. Also I sometimes use an adjustable SSE RF Notch Filter (adjustable from 80 to 190mhz) to remove pager or FM interference,Which depends on the type of Antenna one uses….Works well thanks from Tony.

  2. Max

    This dongle is interesting for users that need to stay on a fixed frequency for long time and mainly for data reception; generic listeners have little advantage. When will be available a dongle with improved shielding and reduction of internally generated signals? Also, i would have liked a bigger pcb with more distance between components and relevant i/o brought out onto pads so that users can easily apply mods to the circuit without risking to destroy it. I do not see the reason to stay on a pcb design born to use the dongle only for tv reception

  3. minime

    too bad that you need to have a paypal account to buy it, just trying with a credit card wont work, they require you to create a paypal account with that…

  4. tom g

    Does this dongle work with the latest dsd+ program released to follow trunked systems talkgroups ?

    • admin

      The dongle is an improved RTL-SDR, which is compatible with Unitrunker and DSD+, so yes it can be used to listen to trunked radio.

    • admin

      It’s just the dongle. But the included antenna that comes with most RTL-SDR dongles is useless, and the remote does nothing in SDR mode, so it is also useless.

      • Ken

        Ok thanks for the information. I went ahead and bought one. Can anyone recommend an antenna to use with this? I’m in an apartment, so Im limited on space and can’t put one in the attic or yard.
        Thanks again

        • admin

          Antenna’s are usually frequency specific, but if you want a wide band antenna i’d suggest a buying a discone or making a yourself a planar disk antenna out of some pizza pans. Put them as high as you can and preferably out the window of your apartment.

  5. Gianni

    A friend of mine and I are ordering two dongles. My in terest is in learning/developing SW applications.
    If this radio is linked to an educational project, where can I get the SW? is it distributed on an Open Project or just the executable? Where can I find schematics?

    • admin

      These radios are based on the common RTL-SDR design, but with a few key improvements including a better & more common connector, a TCXO oscillator and the better R820T2 tuner chip.

      So any software that works with the RTL-SDR will work with this ThumbNet receiver. See the about, quickstart, and big list of supported software pages on this blog for more info on what you can do with them.

  6. Scott

    I purchased 2 of these SDR’s and they work great! After running for hours, the frequency is rock solid. I was able to successfully use SDR# and DSD+ to decode my local P25 channels. I would highly recommend these SDR’s!

    • admin

      Shipping is only charged once per order regardless of how many units you order, so yes there is a bit of a discount for ordering multiple units.

  7. Steve

    With the nice tcxo and the f connector this bring in a interesting concept.
    Has any one done any mods for direct HF,never liked the converter route and for portable setups they where cumbersome my micro surgery abilities are a bit long in the tooth to do the micro transformer change but looking at the picture one can possibly graft a toroid !

    • admin

      These units have pins 4&5 of the RTL2832U chip (Q-branch) brought out onto pads, so they’re much easier to solder to. You can see them on the top right of the PCB image shown in the post, in between the surface mount components next to the RTL2832U chip. So the direct sampling mod is much easier to achieve with these units, though be aware that making a change like this will probably void the warranty.

  8. Martin

    Will this work on Mac, and what software would you recommend for mac? Sky pipe with windows emulation software?

    • admin

      They will work on Mac’s, just like any other RTL-SDR will, though there is much more software for Windows and Linux. I’d recommend GQRX as general SDR software for the Mac. Sky pipe is for radio astronomy.

  9. Dewey

    These are EXCELLENT dongle, but I am having one problem. Does anyone know how to change the serial number? When I try with “rtl_eeprom”, the information that gets written corrupts the dongle info. I want to change the serial number so I can run multiple dongles.

  10. Matthias

    Just a short comment: The “C” in TCXO stands for COMPENSATED, not controlled. Temperature/Oven CONTROLLED crystal oscillators (OCXO) achieve a much higher longterm stability in the range of 1ppb=0.001ppm.

  11. Kevin McCormick

    I ordered two. They arrived very quickly and they are superior to the ones from NooElec.

    I have had nothing but trouble from NooElec’s modded TCXO dongles.

    These dongle work flawlessly.

    Be sure to remove any frequency corrections you have made in you settings.

    If I order any more dongle, I hope they have more.

    • admin

      Thanks for your feedback! We should be in stock for about 2-3 more months unless someone makes a large order. After that we’ll try to get more made ourselves, but we have no guarantees on a time frame for that.

  12. Dave

    Other than the RF connector type and the TCXO, is there any advantage to a Thumbnet unit over one of the new Nooelec ones?


    • admin

      They’re the same functionally other than the TCXO and F-Type connector as you mentioned. But the ThumbNet unit also supports the ThumbNet educational project :).

    • Kevin McCormick

      I ordered a TCXO modded dongle from NooElec.

      The first one did not work at all. Would not even show connected.

      The replacement they sent half works. When you tune the dongle crashes SDR#.

      You have to tune to frequency you want and then start dongle.

      I would avoid NooElec’s TCXO dongles.

      NooElec’s TCXO dongles also cost a lot more.

    • admin

      It will be 75 Ohms, however if you’re worried about mismatch loss just note that any mismatch between 50 Ohm and 75 Ohm equipment is negligible as there will be less than 0.2 dB of loss.

  13. Scott Halligan

    I understand that you’re not the company actually shipping these, but did they advise you of a timeframe for doing so? I ordered mine last Thursday and other than the obligatory order received email I have not heard a thing since. Sure, it’s only Tuesday, but if there is a delay in shipping it would be ideal to know. Thanks in advance.

    • ThumbNet

      Scott, I am truly sorry for the delay.

      We have been absolutely swamped with requests for information about ThumbNet, questions about the surplus receivers and the orders for receivers, since this post went live.

      Your order went out in yesterday’s mail at the post office and I will email you privately with a tracking number in a few moments

      Do not hesitate to contact me with further questions at the address on the ThumbSat website. (



    • admin

      These Thumbnet ones are a little different to the generic models sold by CosyCave and others as they have a 1ppm TCXO and f-type connector.

    • admin

      It uses a R820T2 tuner so the range is about 24MHz to 1.7GHz. It can do any mode since the demodulation is done in software, just like any SDR.

  14. Brandon

    I just placed an order for one of these. I’m new to SDR and I’m hoping this one will have some higher performance than the RTL-SDR R820T that I have.

    Question: When it arrives, I will have two dongles. Will I be able to do trunked radio with them, even though they are different types of dongles?

    • Truth

      The R820T2 is about t 2.7 dB more sensitive than the older R820T (see: ) the clock on this board is 1ppm TCXO, compared to a 28.8MHz XO on a standard RTL board which is about ~30 +-20 PPM at it’s normal operating temperature, probably 100 ppm over the entire operating temperature range.

      I know very little about the trunked radio software, but i suspect that it will be no problem at all, since there is the same rtl2838 chip on on both boards in debug mode. So the maximum bandwidth on both, without dropping samples, would be 2.4MHz.

    • admin

      Yes you can definately do trunked radio even if you have two different types of dongles. The advantage of this one with the TCXO is that it won’t drift off the trunking or voice frequency.

  15. Christian

    For everyone who looking for theory explanation I recommend dissertation
    This dissertation presents an original theory of satellite communication by means of
    Distributed Ground Station System (but in Poland – sorry you could use google translate or you could use your superpower do understand this language 😉 )


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