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

Ganjor86 622132 1575
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  • #93
    Level 15  
    In the case of the E4000, there is no need to remove the capacitors, only the transformer is soldered. For me, thanks to this, the tuner receives in the range from 130 kHz in the mode direct sampling and from 51 MHz in normal mode I / Q - I only switch inputs and change one option in the program. The latest version of HDSDR 2.70 has its plug that takes care of all the settings and runs without any problems. Of course, it is still necessary to replace the driver earlier.

    By the way: does anyone know if you can use any of the tuner outputs as a VFO signal source :?:
  • #94
    Level 13  
    I have an RTL SDR RTL2832U & R820T tuner and I receive all frequencies from about 25 MHz to about 1900 MHz. (10m amateur bands, CB-Radio, aviation band, amateur stations on 145 MHz, and even ADS-B aircraft route tracking on 1090 MHz works). It all depends on the antenna.
    I wanted to listen to hams, e.g. in the 80m band below 25 MHz.
    For this I built two upconverters on the TA7358AP (LA1185) but unfortunately they don't work. I changed about 20 chips, but still the same, no signal at the output (there is only a 50 MHz signal from the quartz generator), as if the antenna was not connected. Electronic components (resistors and capacitors were checked twice in both converters). The 50 MHz generator is also functional in both converters - I checked it with a frequency meter. All the ICs I have are behaving the same. I have 17 TA7358 - from a few different stores and 3 LA 1185. I also have 4 LA1186. Perhaps there is some bug in the design that I built them on.
    Previously, I had fun with Direct Sampling, also featured in the forum on Not Only TV LV5T Deluxe, but I was not satisfied with the results, so I wanted to compare it with the upconver.
    I have a request to my friend "zabex", to include (or send to e-mail: sb8gapi(malpa)o2.pl) the schematic of the converter he built on LA1186, which is on a similar chip as LA1185. Maybe this converter would work for me.
    Alternatively, I post a diagram and materials about the upconverter I have built. Maybe someone will make corrections or find a bug.
    Upconverter comes from the site:
    and here is a pdf with documentation:
  • #95
    Level 22  
    The scheme is perfectly correct. The only difference I have in mine is the connection of an ordinary 40MHz quartz with a parallel capacitor and trimmer to correct the frequency and a narrower low-pass filter. I tested on LA1186 and TA7358AP. I recommend the latter due to less interference and the possibility of going down to a frequency of around 170kHz.

    As for the TA7358AP chips, I bought 5 pieces a few months ago. During the subsequent tests of the converter, I used one of them and no reaction, the other systems behaved identically. My surprise after splitting one of them was endless. The circuit inside was completely empty !!! I do not know if my friend has any proven, tested TA, but I advise you to check it because there are such "rarities" as in my case.

    -------------------------------------------------- -----------------------------
    Since my friend edited his post and added that the systems come from different sources, I can only say that a 100% mistake was made because this converter starts with a "kick".
    Alternatively, when I find time, I redraw mine for comparison. Although not really what.
  • #96
    Level 13  
    I wanted to describe everything as accurately as possible. As far as I know, the LA1185 is slightly different from the LA1186. Do you need to change something in the TA7358 diagram for LA1186 to work, because I guess you need to replace the pins of the integrated circuit.
    I built two thinking I built the first one by making a mistake somewhere. TA7358, which I have, are from several production batches, but it is possible that all of them are "coloring".
  • #97
    Level 22  
    You don't need to change anything. In the prototype version of the converter, I had a soldered socket to the chip and I changed both of them for testing without any problems.

    Write something more about the method of connecting the converter to the dongle and antenna, the supply voltage of the antenna itself, etc.
  • #98
    Level 13  
    I have a power supply for the converter from USB or a 5V stabilized power supply - I used it interchangeably. External antenna from CB Radio. RF-5 cable from the antenna to the tuner. I have a piece of original cable connected to the tuner, the MCX plug to the tuner on one side and the BNC socket on the other. I use different antennas for other bands.
    Without a converter on this antenna, the reception is very good, especially with strong transmitters. After connecting the converter, complete lack of reception of anything, as I wrote earlier, i.e. the same effect as disconnecting the antenna from the tuner - the tuner itself receives nothing after disconnecting the plug from the MCX socket. One converter has filters and the other does not (because I haven't had time to do them yet). After connecting the converter, I do not receive a single station (there are weak radio stations in the ukf radio band, but it is probably from a piece of wire from the converter output to the SDR RTL Tuner. I have this:
    NooElec Brand RTL-SDR, FM + DAB, DVB-T USB Stick Set with RTL2832U & R820T.
  • #99
    Level 13  
    Thanks for the answers and advice. Today I will replace LA1185 (TA7358) with LA1186 and see if it works. I will write about the results on the forum.

    18.12.3013 21:21

    Still the same after replacing LA1185 with LA1186.
  • #100
    Level 12  

    someone thought or made one of his colleagues such a set based on Raspberry PI with one of the available Linux distributions ?? This could be a nice platform. By adding battery power and a small monitor, it would be quite an interesting mobile set.

    Unfortunately, I know the Linux environment poorly, I bought an RPI to experiment. I also heard that abroad they are up to something on this topic. I believe that a POLE CAN CAN and we will be better.

  • #101
    Level 32  
    pablo_doctor wrote:

    someone thought or made one of his colleagues such a set based on Raspberry PI with one of the available Linux distributions ?? This could be a nice platform. By adding battery power and a small monitor, it would be quite an interesting mobile set.

    Unfortunately, I know the Linux environment poorly, I bought an RPI to experiment. I also heard that abroad they are up to something on this topic. I believe that a POLE CAN CAN and we will be better.


  • #102
    Level 13  
    Personally, I have not tested SDR on Android, but I have a tablet and a smartphone, so I will check this SDR Touch. For those interested, he gives a page with other SDR-related applications for the ANDROID system.
    To connect the Tuner with RTL2832U to an Android device, you need an OTG (On-The-Go) cable
    More info here:

    As soon as I get it, we will order a cable, I will test the operation of SDR on Android and I will write on the forum.
  • #103
    Level 13  
    Unfortunately, my HTC Jetstream tablet does not support OTG technology, and the Xperia L smartphone does not have OTG support in the description, but it works when connected via a USB HUB with an additional 5V power supply.
    SDR Touch itself has limited functions in the free version. Only the Pro version for ? 5.99, or about PLN 30, is comparable to PC programs that are free, e.g. SDR Sharp or HD SDR.
    Perhaps on another smartphone (tablet) that supports OTG without additional power supply, it will be a more mobile solution. Unfortunately, in my case, the additional power supply to the USB HUB is not very convenient.
    Instead, I'm using the Asus Eee PC 1001PXD + NooElec NESDR Mini SDR & DVB-T USB Stick (R820T). SDR Sharp. It is quite convenient as a mobile equipment, the notebook battery works 6-7 hours with SDR listening.
  • #104
    Level 21  
    And I have recently a tablet lenovo ideatab A3000 and I am wondering how to connect to it RTL-SDR and Fi-Fi SDR
    but I will rather try to find some version of ubuntu for android. One could make a very mobile listening device :-)
  • #105
    Level 13  
    Lenovo ideatab A3000 has USB OTG (On The Go) support, so you only need a special cable that can be purchased without problems on auction sites and you can directly connect the SDR tuner to USB.
    Just download the RTL2832U driver drivers
    and SDR Touch

    When it comes to installing Ubuntu or any other Lunux distribution on a tablet, it's not that simple, and even a torment. This topic has already been discussed in the forum:
    but as it turns out it is possible:
  • #106
    Level 21  
    Both links are from a year ago and in the field of running ubuntu on android a lot has changed, for example ubuntu touch which is intended for tablets and is said to be easy to install. All that's left is to get to know the possibilities of individual editions and get down to business, but only if I have a sd card for my tablet and an otg adapter.
  • #107
    Level 37  
    There should be no problems with RaspberyPI. Android drivers are actually ARM Linux drivers that work as an android lower layer.

    As RbPI is on Linux for ARM (without android overlay) the drivers will work and the program just needs to be recompiled from x86 to ARM.

    By the way, bouncing from this RTL ... This raspbery basically allows you to connect much better external DAC and ADC on the GIPO (it is even in diy, when someone connected an external driver), it has its own sound card and hardware SPI.

    I think that making a classic DDS + DAC / ADC receiver as SRD would be a much better solution because we also have the option of modulating dsp filters and what dreams :D Perfect radio.

    With the bandwidth, I would have no trouble playing with DDS modules from my friend which are controlled by uart (e.g. pc terminal) and allow a beautiful 200MHz sine.
  • #109
    Level 13  
    Galaxy S III is listed on the creator's website as compatible, so there should be no problems.
    Does the phone see other USB devices - mouse, keyboard, USB flash drive connected via an OTG adapter (cable)? If so, it should detect the USB tuner.
    I suppose Tuner works on a PC.
    I wrote about this a few posts above. I was able to run SDR Touch and the driver on the Sony Xperia L, but only after connecting via USB HUB with additional power and starting the "Root" mode of the phone. Admittedly, on the author's website there is information that "Root" is not required for Android version higher than 3.1, but on my Android 4.2.2 Jelly Bean, without "Root" when starting the driver, even with "Force Root" selected the error was: Unknown error. Only the "Root" of the phone helped.
    I would like to add that the operation of SDR Touh quite quickly discharges the phone's battery, after several dozen minutes (about 30 minutes) it dropped from 100% to 80%, i.e. listening is enough for a few hours (2-3). It will probably work longer on the tablet.
    Before starting the driver, I checked the "Force Root" option.
    I post screenshots from my phone.
    The first is when the driver is started and the second is from a running program.
    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
    As for the SDR Touch itself, the free version lacks "Spectrum", which makes it difficult to use the program, because you cannot see if something is broadcast on a specific frequency or not. You only scan frequencies on the scale. The program crashed several times (driver error), a restart of the phone was required.
    Rather, I prefer to use the PC version. For me, SDR Touch in the free version looks more like a fun program than a functional application. The paid version is probably a bit better (you can see it, for example, in a YouTube video a few posts above), but I did not want to pay about PLN 30. for a program that did not meet my expectations, so I did not test the Pro version. Perhaps someone will like it, the author should be commended for his contribution and that there is such an Android application. It is probably a step towards the creation of other programs as well.
    Maybe these pages will help you solve the problem:
    FAQ on the author's website:
    and xda-developers forum topic:

    Admittedly, the addresses to the mentioned websites are from a year ago, but they were only to be examples that it is possible to run Linux on a tablet or smartphone.
    Of course, you can combine the construction of more complex devices, but you have to answer whether it is worth it, significantly increasing the cost of the entire device.
    The tuner itself on RTL costs about PLN 30 + making an external antenna about PLN 30-50, so the cost is small, and the effect is really great at the costs incurred.
    For beginners, such a solution is cheap and gives good results.
    You can play with SDR Touch, but in the free version, SDR Sharp for PC is not up to the heels, which is free so far. Only in the paid version, it slightly resembles Sharp's SDR, but leaves a lot to be desired. These are my personal observations and I do not want to alienate anyone from Android, and I also had some problems with the installation on my Sony Xperia L. It is probably also a matter of the hardware itself.
    As for Linux and the software for this system, I have not used it, so I will not comment.
    In summary, anyone interested can choose between different hardware and system platforms, and each solution has its own advantages and disadvantages.
  • #110
    Level 13  
    Thank you to the "Zabex" forum member for the TA7358 converter scheme (LA1185, LA1186 can be used) for the USB RTL SDR tuner that allows you to receive frequencies below 24 MHZ - from about 100kHz to 40 MHz. I was able to finally run it according to the diagram sent by "Zabex". I found a similar scheme on the internet, which I also used and post it, because it may be useful to someone.

    Page with description and diagram:
    and here is the diagram:

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

    Drawn by hand, but it is legible and proven.
    I had the opportunity to compare Direct Sampling and converter performance. The converter is much better and no tuner modification is required.
    The replacement LA1185 - AN7205, which I bought 2 pieces in the SŁAWOMIR Electroniics movie, also works well, it works even slightly better than the TA7358 (cleaner signal, less interference, and a higher signal level).
    This is such information, if someone needed chips from a proven source.
    The LA1186 works in the converter, but is noticeably less sensitive than with the LA1185 and TA7358.
    As I wrote earlier of all the systems, I have about 25 from different stores, and it turned out that some of them do not work, as "Zabex" wrote when he found "empty inside".
    Confirmation of the converter operation on a 40 MHz quartz resonator and LA 1185 - reception of Polish Radio I at 225 kHz (weak signal, because the experimental antenna consists of a few meters of cable).

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

    Another screen of the converter operation on a 50 MHz quartz generator and LA1185 - reception of Polish Radio I at 225 kHz and you can see other stations received on long and medium waves.

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

    The previously described TA7358 converter with a 50 MHz quartz generator works if everything is done according to the diagram (I had a problem with starting it up, because my design had a bug, but after checking it worked). A converter with a quartz generator performs better - better sensitivity and less interference. The LA1185 IC works best, then the TA7358 and AN7205, but the difference is small (it also depends on the specific unit).
  • #111
    Level 13  
    For several days I tested converters - one built with a quartz generator and the other with a quartz resonator. I would like to make some comments that may be useful for someone who would like to make such a converter.
    Each has its own advantages and disadvantages.

    The converter with a quartz generator has noticeably better sensitivity, but the generator frequency shift is 3 kHz (it is smaller - for a 50 000 kHz generator the shift in SDR Sharp - the Shift option is 49 997 kHz - you can see it in the SDR Sharp screen above) I don't know what it is is caused, and I checked on several generators and ICs, and it was unchanged. Maybe someone met with such a case.
    The schematic of the converter is a few posts above.

    Converter on a quartz resonator (I used a 40 MHz quartz resonator at home (without an additional adjustable capacitor), it had lower sensitivity, but the shift was equal to the resonator frequency. You can see it in the SDR Sharp screen. I can still adjust the gain in Configure -> without Tuner checked AGC - with a slider. To build a converter with a quartz resonator, I used the same scheme as for the previously described converter, but instead of the generator and all the elements associated with it, I connected the resonator directly to pin 8 of the IC, as you can see in the diagram drawn by hand with a quartz resonator .

    After checking the operation of several dozen integrated circuits, the LA 1185 works best in the converter circuit, then the TA7358 and AN7205 and the LA1186 works the worst.
  • #112
    Level 9  

    I would like to get a dvb-t listening scanner because I cannot afford another scaner. I have a few questions:
    Is there a list of proven tuners available at Polish auctions somewhere?
    Which tuners do you recommend? (no holes in the band)
    Is there any installation tutorial, or maybe you don't need it, because all you need is a soft SDR and plug in the USB tuner and it will start ??

    Best regards!
  • #113
    Level 13  
    First, the tuner must have RTL2832 + tuner chip, preferably R820T (currently the best).
    Please read this topic from the beginning and:
    Description of the installation, e.g. here:
    YouTube guide:
    For collection, I recommend the program for Windows SDR Sharp and possibly HD SDR.
    and here from another forum shortened frequency division:
    As for tuners on the Polish market, these are Allegro:
    http://allegro.pl/tuner-dvb-t-hd-mpeg4-rtl2832u-sdr-najnowszy-model-i3873743138.html and I also recommend this tuner.
    I personally bought 2 pieces on ebay from china:
    http://www.ebay.com/itm/BF9-Good-Software-Rad...l-TV-Receiver-/181250115475?ssPageName=ADME:L :O AT :P L: 3160
    It is identical to that of the Allegro.
    These are just examples and at the end I would like to add that it is worth paying attention to the protective diode at the antenna input when buying.
    RTL-SDR - an SDR receiver from a cheap DVB-T tuner on a USB connector
    The tuner with the R820T itself allows you to receive frequencies from about 24 MHz to about 1700, but you can increase the bandwidth thanks to the converter for LA1185 (TA6358) described in this topic.
  • #114
    Level 29  

    The better sensitivity is due to the higher signal level from the generator on the mixer. The internal circuit (leg 8) with quartz works as a generator, but the external generator connected to it makes it a repeater (an amplifier with a low gain). Hence the greater signal on the mixer. If you would make a separate quartz generator, e.g. on one transistor, and connect it to the system, you would also notice better sensitivity.
  • #115
    Level 13  
    I guessed that there would be more sensitivity with the generator, but thanks for the answer and the detailed explanation. I am wondering about another problem. I wrote about the fact that with the generator there is a shift not by 50 MHz, but by about 3 kHz less, i.e. 49 997 kHz. Maybe someone knows if this can be changed or what it is caused by. I adjust the gain level in SDR Sharp to the level of the best reception with minimal distortions and interference. I experimentally built a converter with a miniature switch so I can choose between a quartz resonator or a quartz generator.
  • #116
    Level 32  
    You can correct the shift by means of the PPM function in the program.
  • #117
    Level 13  
    I know that it can be done in the program, but I mean, can it be done in a converter?
    I changed the quartz generators and circuits, but no changes. I measured the frequency of the generator and it is equal to 50,000 kHz in all 4 I have. Maybe today I will put a quartz generator on a different frequency and then check it.
    My converter:
    RTL-SDR - an SDR receiver from a cheap DVB-T tuner on a USB connector
    and on the screen:
    RTL-SDR - an SDR receiver from a cheap DVB-T tuner on a USB connector
  • #118
    Level 9  

    I have a problem installing / running rtl-sdr shharp. I do everything according to the instructions ....
    I unpack the sdr # in any location, then install ExtIO_USRP + FCD + RTL2832U + BorIP_Setup, the modem has drivers installed ...
    I fire up sdr # and in the selection window I do not see RTL-SDR USB, only RTL-SDR / TCP ???

    RTL-SDR - an SDR receiver from a cheap DVB-T tuner on a USB connector
  • #119
    Level 13  
    You should enter the folder with SDR Sharp. If there is a Config folder there, go to it and copy the file: SDRSharp.exe.Config to the main program folder. If there is no this folder, you need to edit this file: SDRSharp.exe.Config from the main folder, because by default RTL USB support is not active.
    Open the file in the editor, e.g. Notepad and go to the section at the end of the file:

    There will be something like this:

    and you need to delete (at the end) to get this entry:

    And we save the file.

    I also present the latest version of SDR Sharp on 14/01/2014 with RTL USB support enabled.
  • #120
    Level 9  
    Thank you very much!

    The first observations are very few stations :( even on VHF I have only two radio stations? What could it be? Antenna?