RTL-SDR - an SDR receiver from a cheap DVB-T tuner on a USB connector

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  • #1472
    Level 12  
    Here https://gqrx.dk/ is described the program and its possibilities ....
    On Linux, you connect RTL to the USB port, press PLAY and it's supposed to go.
  • #1473
    Level 21  
    Koczarq wrote:
    I have a Not Only TV LV5TDLX dongle. It is on the RTL2832u and E4000 chip.

    I connect the dongle, the computer (win 10) sees it in the device manager. I download the package from SDRsharp, everything installs neatly, installs the driver using zzadig. The program sends a message saying that the installation was successful.

    And here comes the stairs ...
    I turn on SDRSharp and quickly select the Source: Rtl-SRD ((USB) settings and click PLAY, even something goes to listen, but after a few seconds the dingle disconnects and you can no longer see it in the manager. If I do not turn on the SDRSharp program, the computer can see it all the time, only when you turn it on, do such things happen.

    Tried disabling power saver on usb.
    I checked on my second computer, also from 10 wines, the same thing happens.

    Do you have any ideas what could be wrong?

    Certainly it is not the fault of the rudders because the program would not turn on at all. I turn off the tuner in SDRSharp and HDSDR when I have too much CPU and memory load. When I listen to these programs, I have other programs turned off and net. If the program hangs like this and I don't see the tuner, I have to unplug it and plug it in again, so I often use SDRConsole V3, a very nice free program for Windows and the tuner does not freeze.
    Test it on other programs and check what your CPU and memory load is when running the programs. In desktop gadgets you have a CPU meter, you can monitor the load on it. If you have over 80%, you may have problems with the operation of these programs. Unfortunately, on the full graphics settings and other AERO functions on Win7, I did not run the program at all, I had to lower the settings to the minimum.
    RTL-SDR - an SDR receiver from a cheap DVB-T tuner on a USB connector
  • #1474
    Level 2  
    Thanks for the answers

    I checked out various options.

    Yesterday I was able to run it with SDRSharp for a few hours, everything worked without any problems. This morning I was also able to listen to the same program, but after maybe an hour of listening, the manure split off in Windows.

    I tried to connect and disconnect it, but it still turned off after a few seconds.

    Now the situation is that the system does not see it at all. Even on the second computer.

    Rather, it does not look like problems with the load on the computer, because when it worked, it worked without problems for several hours, and the computer does not have a poor specification. The rest of the problem is identical on the other computer.

    Do you have any more ideas, because I'm over now ...?
  • #1475
    Level 2  
    I think I have solved the problem :D

    I have reinstalled the USB output drivers and so far everything works fine.
  • #1476
    Level 21  
    tygrysss wrote:
    Gentlemen, the question - I put rtl-sdr on lubuntu 18 and run rtl_tcp on it - on the desktop in sdr # I set the server and after connection there are all the cuts. The sound shreds.
    CPU utilization on the server 8%, RAM 20% - LAN connection.

    I also tried on raspberry - same, chopping sound.
    In addition, the sensitivity of the receiver is worse on both, it collects poorly even the local FM radio.
    After connecting directly to the USB client computer, everything is OK.

    Has anyone experienced something like this?

    I raise
  • #1477
    Level 13  
    Currently, I have a tuner connected to my laptop with Windows and sdr sharp software, but I would like to free myself from the cable, so I plan to connect the tuner to the rpi and then stream the signal to my laptop.
    What program on rapsberry pi would you recommend to handle rtlsdr as a server and on windows as a client.
    PS. Ideally, the program should generate as little network traffic as possible, below 1 Mbpsm, preferably around 0.5Mbps
  • #1478
    Level 21  
    Hello. If someone uses regular DSD in the old 1.7 version, I recommend that you have a look at this page, the project has been restarted and now version 1.8.2 is available for download. Versions worth testing.

  • #1479
    Level 12  
    Hello, I have a question, if I have to move the antenna and the antenna cable will be about 50m, will I have to give an antenna amplifier?
    If so, what?
  • #1480
    Level 21  
    I believe you mean frequency listening. It all depends on what cable it is, give the symbol and what frequency you want to listen to. The lower the frequency, the type of cable does not matter much when it comes to its length.
  • #1481
    Level 12  
    I mean the frequency ranges from 148mhz - 175mhz. The sdr tuner I have this blue chinese. As for the cable, I'm going to buy a good quality 75ohm coax. Since I already have a 75ohm concentric to the attic where the antenna used to be, but because I am replacing the roof with a metal tile, I have to put the antenna outside and as far as the distance is concerned, I found a place closer to 30m.
  • #1482
    Level 21  
    As for the cable, I recommend the 50ohm H155. It is a cable with good parameters, low loss and is most often used on 2.4GHz wifi. I have the same one in the antenna installation for the tuner and it is better than the 75ohm cable. As for amplifiers, somewhere in this topic I described how to connect them and what types I recommend. I am currently using two SWA9701 and ABL-21 amplifiers.
    It is best to mount the amplifier close to the antenna, I have it done. 30cm for the antenna in a hermetic housing I have SWA9701 I did one more thing, I soldered this choke on the back of the plate from photo 1 and connected the antenna with a cable directly to these contacts as in photo 2.
    Photo 1
    RTL-SDR - an SDR receiver from a cheap DVB-T tuner on a USB connector
    Photo 2
    RTL-SDR - an SDR receiver from a cheap DVB-T tuner on a USB connector
    Main vein red.
    Yellow cable braid.
    The power supply may be 12v but I use 13.8v and it works fine. You will also need a voltage separator similar to that of the tv antenna.
    Power supply with a separator
    RTL-SDR - an SDR receiver from a cheap DVB-T tuner on a USB connector
  • #1483
    Level 21  
    I have a question, maybe someone knows what the problem is. It is about "painting waterfall" and some other elements in a few programs. Two different computers the same system is Windows 7 64bit SP1. In this case, we will describe the SDRAngel program. In the photo you can see empty fields where the spectrum and constellation should be visible, on the other computer it is visible. Anyone know what the problem is?
    RTL-SDR - an SDR receiver from a cheap DVB-T tuner on a USB connector RTL-SDR - an SDR receiver from a cheap DVB-T tuner on a USB connector
  • #1484
    Level 9  
    The thing you have desoldered is the antenna impedance transformer. Due to the fact that I have good experience with closed dipoles, I would encourage you to re-solder it and use such an antenna. The second option is to place the antenna on a mast that extends above the roof of your home and forego amplifiers. And so there is no need to count on pickups over 100km. I am referring, of course, to the reception of the stations you want to listen to.

    PS. use the dipole only, without reflectors and directors. Here it is worth giving up directionality in favor of omnidirectional. It's enough for these solutions.
  • #1485
    Level 21  
    If someone uses dipoles as antennas, he can leave them behind. Unfortunately, I use mostly collinary antennas and unfortunately the reception was worse due to this transformer, so I propose to unsolder it. As for the reception of the station, if you have a well-made collinary antenna calculated for a given band and amplifiers, you are able to receive the station from a distance of over 100 km. The sdr tuner has a poor internal amplifier, besides, there are also cable losses, so it is better to use the booster as close to the antenna as possible and in the program you set a lower gain, which eliminates the interference from the tuner itself.
  • #1486
    Level 21  
    This transformer is used not so much to convert the impedance, but to match a symmetrical antenna, such as a dipole, to an unbalanced transmission line, which is a coaxial cable. Its purpose is to prevent the cable braid / shield from acting as an antenna.
  • #1487
    VIP Meritorious for electroda.pl
    BOOM i ZONK wrote:
    This transformer is used not so much to convert the impedance, but to match a symmetrical antenna, such as a dipole, to an unbalanced transmission line, which is a coaxial cable. Its purpose is to prevent the cable braid / shield from acting as an antenna.
    You're wrong. The SWA-9701 referred to here is a 300/75 Ohm transformer.
  • #1488
    Level 21  
    @ SP5IT Is it only a 300/75 transformer ?? God forbid, it does not deny that there is an impedance matching in it. I am writing this in the context of the collinear antenna used by the col. @don_viking - I treat it as an unbalanced antenna, in this case I consider using a Bal-Un 1: 4 transformer a bad idea. The mismatch between the impedance of the antenna and the impedance of the coaxial cable should with an increase in attenuation - is it so? I mean Bal-Un rather than 1: 4 to avoid a situation where the shield of the coaxial cable does an unwanted part of the antenna, raising the background level.
  • #1489
    Level 12  
    don_viking is on frequency 150 mhz MHz what antenna do you suggest?
  • #1490
    Level 21  
    As for this frequency, I recommend the so-called "truncheon" antenna, they are often offered to buy used from a railway surplus. Or the simplest 1/4 wave GP antenna. It is a specific frequency in terms of wave propagation, therefore no complicated antennas are needed to receive signals from further distances.
  • #1491
    Level 12  
    Good morning everyone
    I've read read, watched different pages and diagrams and have an idea, maybe silly. I know that it is silly because the amplifier is an amplifier, and the high-pass input filters will do their job instead of the high-cut ones. So it must be abandoned
    Maybe someone was trying to do something like that?
    I am waiting with the tests for a new dongle from "my friends" in a larger size.
    Currently I have the smallest black "square" without heat sinks and in plastic.

    By the way: the overheating R820T tuner had to be watered with a little tin in the hole on the other side of the plate (a big improvement)
  • #1492
    Hektar Zahle.r
    Level 29  
    Hello comrade!

    Referring to the question - Link - I decided to force Overmax Quattor 10+ to cooperate.

    This equipment on Android 4.2 is currently rather only for fun, but the batteries are still good, it is failure-free and has 10 inches. There were three hooks, or actually two: root, which could not be done at all (only one way worked), no drivers and no USB Host, so other SDR applications do not work, and SDR Touch and yes. I have bought some of it in bulk as an outlet for about PLN 40 / item. Despite the weak processor it works quite well with full 2 MHz coverage.


    By activating developer options - Link - enable USB debugging so that the rooting program can connect.

    RTL-SDR - an SDR receiver from a cheap DVB-T tuner on a USB connector

    Install the tablet drivers on the computer, run ZhuoDaShi, connect it to the computer and click this button.

    RTL-SDR - an SDR receiver from a cheap DVB-T tuner on a USB connector

    And then this button.

    RTL-SDR - an SDR receiver from a cheap DVB-T tuner on a USB connector

    The ZhuoDaShi logo will appear on the tablet while rooting.

    RTL-SDR - an SDR receiver from a cheap DVB-T tuner on a USB connector

    Install the oldest known to me RTL2832U_driver_2.2 (none newer will fit) and select (permanently) Force root - Start should result in such a message.

    RTL-SDR - an SDR receiver from a cheap DVB-T tuner on a USB connector

    From now on, the driver is ready for operation, and if it does not, it throws such a message.

    RTL-SDR - an SDR receiver from a cheap DVB-T tuner on a USB connector

    Check the physical connection of the RTL-SDR with the OTG cable to the tablet as well as the voltage supplying the adapter.

    Importantly, the USB HUB is unnecessary, the OTG cable has been detected and supplied with a sufficient current of 300 mA from a separate converter - although the OTG tablet does not have.

    Additionally, in order for the program to start by itself, it is worth adding the application to the autostart.

    RTL-SDR - an SDR receiver from a cheap DVB-T tuner on a USB connector

    Unfortunately, no SDR or DVB-T program on this equipment will go (no OTG) - apart from the most important.

    RTL-SDR - an SDR receiver from a cheap DVB-T tuner on a USB connector

    Interestingly, inside the tablet, in addition to the USB dongle, there will be another 7.4V / 6Ah battery of the same type.

    Necessary applications and drivers are attached.
  • #1494
    Level 21  
    Hello. Recently I launched sdrtrunk v 0.5.0 alpha 6 on windows and set up a few channels in DMR. It turned out that the program has the ability to decode many channels at once and, more interestingly, the voice is much better than in dsd +. There is an event window, map and other useful functions, the decoder even shows broadcast LRRP information that dsd + cannot decode. The problem is that in the alpha version it does not show the LRRP position on the map. But it shows the positions on the map in the P25 system.
    Link to the program.

    Link to the disc with photos from the program.

    I recommend especially to those who want to listen to many DMR channels and be up to date.

    After completing the data in the "Alias" tab of individual groups and adding "Identifiers" and selecting "Record", the program records each group separately. Pictures from the settings at the link to the disk above. The audio files are located in the "recordings" directory and the path is set in "Users Preferences" "File Storage / Directories".

    After further tests, I can say that the load on the processor and memory with two tuners running in two program windows is small as you can see in the photo. Also, if someone has the option of dividing the desktop into two different monitors, this is a great thing and one panel will be visible on each of them.
    RTL-SDR - an SDR receiver from a cheap DVB-T tuner on a USB connector
  • #1495
    Level 21  
    Does anyone know what is installed in "NotOnlyTv" tuners, whether they are TCXO or ordinary resonators. The housing looks like the TCXO has 4 pins, and on the housing at the top it writes XTY 28.800 on another D3AA 28.800. XTY and D3AA, I think they are the names of companies, unfortunately I cannot find a picture and description of this element on the net. Pictures come of poor quality at the link below. Tuners
  • #1496
    Level 43  
    don_viking wrote:
    has 4 pins

    Maybe it is an integrated quartz generator (SMD)?
  • #1497
    Level 21  
    They are similar in the new tuners in blue housings, only slightly larger and these are ordinary quartzes. From what I found on the network it seems that not all TCXOs have 0.5PPM, there are also those with + - 23PPM. and even more.
    I mean, has anyone soldered something like this generator instead of quartz and whether the frequency floats on it like on ordinary quartz when changing the temperature or not?
  • #1498
    Piter K.
    Level 23  
    These are regular IC generators, not TCXOs. Unfortunately, as if we were not enchanting reality, these are only integrated generators. The case is prosaic. Nobody will pack TCXO into the TV tuner, because it does not make any sense. If the plug is designed as a broadband receiver, then something else. But the NotOnly series tuners were designed as RTV receivers, and their price indicates that the matter was not approached with unnecessary momentum.
  • #1499
    Level 32  
    Even ordinary quartz are in housings like ordinary quartz generators and TCXO, such versions of quartz were also installed in these tuners. This can be checked if we have an oscilloscope. In general, in some "blue" tuners, in the place where there is quartz, whether traditional or SMD, there are solder pads, including the power supply for soldering the generator / TCXO.

    TCXO 28.8MHz with 0.5 PPM can be purchased at Aliexpress for about PLN 20 - is it profitable?

    RTL-SDR - an SDR receiver from a cheap DVB-T tuner on a USB connector
  • #1500
    Piter K.
    Level 23  
    I bought TCXO for PLN 48. 0.3ppm. Of course, not for RTL SDR, because such a cube is like half of a RTL plug. Now the question is what someone will use an RTL SDR receiver for. Does it make sense to buy such a receiver for $ 10 and also TCXO, then play with the exchange and have stable crap? And you can immediately buy a "Newgen" type receiver with TCXO at 0.5ppm, with chip cooling and filtering, and a bias tee, for, say, PLN 60, without a spin. R820t, no matter 1 or 2, without cooling has terrible parameters. And here it seems more reasonable to add a cooling system than TCXO. But it depends on who likes what. I personally find RTL SDR fun to start with. Later, it will be more appropriate to switch to a receiver with MRI systems. And you can get these for less than PLN 200. I even saw for PLN 150. The receiver does not require cooling, has TCXO 0.5ppm on board and works from 1kHz to 2Gz. But more importantly, it has much better dynamics, does not require a converter to receive shortwave, has a built-in preamplifier and does not have problems with reception above 1.5GHz. R820T / 2 without cooling, above 1.5GHz will lock. A special driver is required, but I have serious concerns about the parameters of the chip, which heats up to a temperature above 70 degrees. He will pick up, but that is all noise. Only when it is cooled down do the signals suddenly break out of the noise. At 35 degrees, the noise is there, but with amateur use it is not a problem. Cooling in general, in the entire reception band, improves the parameters. The noise drops drastically. I was amazed at how much better cooling is. Therefore, I consider buying a TV-type receiver and adding TCXO pointless. If we insist on RTL SDR, it is better to buy one in a metal housing, with SMA and TCXO connectors and not bother with soldering. Well, unless someone has free equipment, patience and nothing to do with time ...