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

Ganjor86 682870 1593
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  • #571 14997073
    methyl
    Level 16  
    Pictures of guts very similar are here.
    RTL-SDR - an SDR receiver from a cheap DVB-T tuner on a USB connector

    It is clear that it is an ordinary dongel soldered to a PCB on typical components, on which we have a low-pass filter, a quartz generator powering the mixer, the diode mixer itself (double-balanced) and a high-pass filter at the output. I will look for an identical photo yet.

    Write what ranges are you interested in, but in general, you should give a high-pass filter that cuts off the radio range and it is good to cut off the GSM bands and everything that is strongly given after the receiver enters. The best resonant antenna for a given range is DC shorted.

    I do a high pass filter for the receiver is a pimple, I can help.
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  • #572 14997198
    Anonymous
    Anonymous  
  • #573 14997300
    don_viking
    Level 21  
    You enter the page below, enter the original link in the left window, set the language to be translated and in the right window you have a link to the translated page.
    https://translate.google.pl/?hl=pl
  • #574 14997320
    Anonymous
    Anonymous  
  • #575 14997327
    don_viking
    Level 21  
    Well, I wouldn't say that I often use such a translation and you can understand everything. I also often use the website http://pl.pons.com/translation-tekstu
    there you won't translate the whole page because there is a letter limit. I doubt that there is a page in Polish with such descriptions and the only thing left is a translation on foot.
  • #576 14997331
    Anonymous
    Anonymous  
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  • #577 14997417
    methyl
    Level 16  
    It is best to put a ready-made antenna on a plate. There is a lot of it on the net. Biconical, bicone, antenna for scanner or anything else and look for. Broadband antennas come in many varieties and designs.

    Check out some photos of making such antennas, even from clothes hangers :D

    Link

    Here is a description of another implementation:
    Link

    Basically it's such a widened vertical dipole. Instead of the arms of the dipole, there are cones, e.g. made of metal mesh, sheet metal, or just a few wires on the contour of the cone.
    The length of the wires that make up the cone can be taken as 1/4 of the length of the longest wavelength that we will receive. Such a calculation is sufficient for receipt.

    Maybe I'll paste some theory later.
    Google "AWX ANTENNA" is also such a two-cone only one-dimensional and does not collect the signal evenly from all directions. Interesting because it can be made as a simple antenna for transmitting two bands 2m / 70cm but it is for those with a license ;)
  • #578 14997481
    Anonymous
    Anonymous  
  • #579 14997538
    methyl
    Level 16  
    This question cannot be answered unequivocally.
    If it were that easy, everyone would have one antenna model, the best one ;)


    If you listen to everything in the range of e.g. 108-2000MHz, it is a discone or bicone antenna. It has its pros and cons. The upside is the wide reception.
    The downside is lower sensitivity than a band tuned antenna.
    The downside is that it collects so widely. If there is a transmitter nearby that rebroadcasts a commercial radio station with the right power, you are guaranteed to jam the receiver with a high-value signal.
    I had it and I had to equip the DISCON with a filter that cuts the 88-108MHz range.

    Of the antennas that I know and tested, the cones made of wires or hangers as in the above lines are quite acceptable and work similarly to the factory DISCON.

    If we are only interested in, for example, the AIRSPORT band, then ignore the broadband antennas and make a simple SLIM JIM or J-POLE antenna.

    It works a bit better, wider than an ordinary half-wave dipole, and is also DC-compact, so it is safer for the receiver in the event of a storm or static charges.

    I recommend this calculator:
    Link

    Anticipating some of the questions, I answer.
    Yes, at the bottom of the antenna the cable is short-circuited to DC with this bottom "U" -shaped part of the antenna and that's ok. this is not a short circuit :)

    This antenna has one more advantage, it can be extended through successive half-wave fragments connected through "quarter-wave transformers" which gives us additional profit with each additional element added.
    And to do it is no problem:

    Link
  • #580 15002103
    Anonymous
    Anonymous  
  • #581 15002157
    methyl
    Level 16  
    You have all the information you need in a few posts above.
    If you are not satisfied with the range at a frequency close to the one for which your dipole was calculated, then the construction of a broadband antenna will not improve anything here.
    Typically, broadening the antenna reception bandwidth is associated with a loss of profit.
    If you want to have a good reception, you are left with the roof or the highest balcony and mast, e.g. at a good neighbor. For this a good cable and antenna are best for a specific band that interests you. There are simple high-gain antenna designs to be built at home, e.g. collinear antennas, unfortunately they are quite narrowband antennas.

    You can also use simple directional antennas. The MOXON type antenna works very nicely. Construction and calculators for calculations ---> google.

    Calculator for DISCONE ANTENNA ---> GOOGLE
    example: Link
  • #582 15004558
    MORZEBALTYCKIE
    Level 11  
    methyl wrote:
    Pictures of guts very similar are here.
    RTL-SDR - an SDR receiver from a cheap DVB-T tuner on a USB connector

    It is clear that it is an ordinary dongel soldered to a PCB on typical components, on which we have a low-pass filter, a quartz generator powering the mixer, the diode mixer itself (double-balanced) and a high-pass filter at the output. I will look for an identical photo yet.

    Write what ranges are you interested in, but in general, you should give a high-pass filter that cuts off the radio range and it is good to cut off the GSM bands and everything that is strongly given after the receiver enters. The best resonant antenna for a given range is DC shorted.

    I do a high pass filter for the receiver is a pimple, I can help.


    Everything is understandable. Thanks alot.
    I have a suitable antenna, and I am interested in the low VHF and the range above the amateur 2m band, airband and broadcast do not interest me. I will order and see how it works.
  • #583 15004588
    methyl
    Level 16  
    To be sure, before your purchase, I will add again that it is an ordinary USB whistle "SDR RTL" with an additional converter board attached when you want to go below 30MHz and manually activated with a switch. If you are not interested in KF, buy a regular R820T or R820T2, you will save a lot of money ;)
  • #584 15004610
    lysy1980
    Level 33  
    I hasten to explain that the receiver from the post
    https://www.elektroda.pl/rtvforum/topic2353101-540.html#14996914
    it is not built like the receiver shown above. The nicely taped one from the quoted post looks like this:

    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

    and it uses the DIRECT SAMPLING modification on the Q channel as I remember correctly and has no converter. The set also includes the Nagoya UT-102UV, and of course it's not worth the money.
    If it was built on a mixer (converter) it would be a better solution and it would be worth giving more for it.
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  • #585 15019377
    methyl
    Level 16  
    Yes, right here you can see that in this performance it is direct sampling.
    But in the previous one, both in the PCB layout and on the colored sticker on the housing, you can see that there is a built-in KF converter there.
    Also, I think that the option with a converter is better, as long as someone is interested in listening to KFu at all. You can see a simple low-pass filter in the photo and a transformer on the ring attached directly to the chip. I used to play like this and even that was perceived, but it pissed me off the most that above half the frequency of the local oscillator, i.e. 28.800MHz, so 14.400 began to receive what it should and additionally mirror what was below. You have to give switchable filters or bandpass filters. Then it would be good to listen to it.

    Here you can see the above system better:

    Link
  • #586 15057642
    andrzejz78
    Level 19  
    Hello

    For several days I have been playing a bit with listening to different bands, but something does not work out too much I will add that I live in the countryside, low-rise buildings, flat area

    The tuner is such an invention

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

    I have good reception of the FM radio band and some aviation band. On other frequencies I do not catch anything even though something should be

    For example, in the range of 26-30MHz I should catch something because CB works there and for me there is total silence, and no matter how in the program I set the parameters

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

    There are only a few radio stations around 7Mhz and nothing else

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

    In the vicinity of 160-180Mhz there is nothing left and the services should broadcast in this band

    I carried out tests on various makeshift antennas. I wanted to see if I would catch anything in the CB band and the services. If I caught anything, I would make an antenna for the selected band or buy something ready-made
    Now I wonder if I am doing something wrong that I only have a radio and aviation band or maybe I live in such a radio hole

    If someone could direct me in action, I would be grateful
  • #587 15057667
    lysy1980
    Level 33  
    Bandwidth below 25MHz in these tuners is a mistake, either building a converter or doing Direct Sampling. Makeshift antennas? What do you mean? The services are not broadcasting non-stop. You are quite far to the cities so there is no strange silence. Throw the antenna a few meters up and it will start moving. Set the gain higher in the program.
  • #588 15057981
    andrzejz78
    Level 19  
    I have 15 km in a straight line to the city

    Makeshift are various "sticks", straight dipoles or TV antennas I just wanted to check if something is coming to me I am surprised only that I have nothing from the CB band

    I had the antenna about 8-10 m above the ground because the cable did not allow higher up
    Can you test on a TV cable? I have it much more than this 50ohm

    Possibly, it remains to take the risk and buy a ready antenna. At most, I will utop a few zlotys ;)
  • #589 15058018
    lysy1980
    Level 33  
    There may be a TV cable, CB is not crazy about the range either. If you do not live near a busy road where there is no police car with a video recorder or it is not "drying", then silence. Check if you receive a digital phone around 168-170MHz.
    I will only add that if you played with TV antennas with an amplifier (mesh inventions) and you had the tuner gain set to MAX, there is a good probability that you beat the R820T.
  • #590 15058026
    Ganjor86
    Level 21  
    And I live in Leicester and there are over 350,000 inhabitants, and then Lime receives nothing except a few VHF stations and sometimes an airline. The dongel is with the R820T tuner and the antenna is a cable from the original antenna and a single-core cable with a shielded cable connected to a hot wire. I have a lot of strong interference repeating at regular intervals and the receiver is generally not good for anything. I would like to enclose the receiver in an aluminum box together with a decent LNA and upconverter. Now I wonder how to do it, as long as the way of placing the dongle in the aluminum box was discussed very recently, the matter is not clear to me regarding the LNA and upconverter. I do not know what upconverter and LNA should be made and whether they should be separated from each other inside the housing by means of aluninium walls connected to the ground of the device. What thickness should the walls of the box be and whether aluminum is the best material and whether it is worth using ferrite filters on the cable.
  • #592 15058154
    lysy1980
    Level 33  
    Now I have no way to show you the screenshot because on the computer I am using now I have nothing for SDR

    This is what a digital phone should have around 168-170MHz
    https://www.youtube.com/watch?v=D44NYGwS2OY

    Yagi probably on UHF so logically you won't get anything from the CB band.

    As for the Discone - I will not say anything, I have never used it - I have SIRIO GP3E installed at home and it is fine for me - I am interested in the air band plus services with an emphasis on the first - I use a scanner connected to this antenna, not a tuner, on a daily basis.
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  • #593 15058302
    andrzejz78
    Level 19  
    I tried to catch the CB band on a stick and not on Yagi
    I know a little what it is for ;)

    As for the digital, I don't have anything like that in the 168-170 range
    I changed the position of the "stick" antenna and I catch something around 21mhz so I think I will invest in a ready antenna
  • #594 15058444
    lysy1980
    Level 33  
    I understand, I translate automatically with antennas because I have clients who think that they will receive CB on a stick from the set and are surprised that you can not hear anything, so the tuner is broken.
    However, if you have entered the correct city in your profile, you will not hear anything interesting from Radzyń and Łuków - Lublin is heated with digital heaters. The busy Lublin - Warsaw route is also quite far away, so CB will not necessarily pick up.
    If you hear aviation OK, then you can deduce from the correspondence what point is reported by the plane, e.g. BIGLU, BOKSU, RUTKA, USTIL, DIBED and you know where you hear it from.

    Here you can check where what is (e.g. BIGLU):
    https://skyvector.com/?ll=51.72294495494698,23.542968752762658&chart=304&zoom=3
  • #595 15058875
    andrzejz78
    Level 19  
    Yes, the place is correct

    I was hoping that something would come from Łuków

    As for airplanes, it's hard to catch something in Polish and besides, I have to deal with the antenna first

    Can you send me some simple description for decoding the digital phone with DSDPlus etc.? I want to get too much in recent days and I already have a confusion in my head and I do not get much of foreign descriptions
  • #596 15059237
    lysy1980
    Level 33  
    I didn't play with it that much. I recommend a friend don_viking - He knows a lot about these things.
    As for the air band, listen to the correspondence with the tower from the EPLB at 134.625 - you should hear correspondence in Polish - you are close to Lublin, or at 119.450 - Wawa Info - the mast at the EPLB port is standing.
  • #597 15060839
    don_viking
    Level 21  
    Hello andrzejz78 below in the link is a description of setting the options in the SDRSharp program so that you can receive digital modulation well and decode with the DSDPlus program. The basis is the Virtual Audio Cable program. I recommend version 4.10 for me it works satisfactorily, so I did not install newer versions. After setting the options as on the page below, you will not hear what is happening in the air in the loudspeakers, only the modulation decoded by the DSDPlus program. If you want to hear what is hum in the air, you need to turn on the repeater, but I recommend the KG-TONE program, and you will see CTCSS, DCS and DTMF tones broadcast by stations. You only need to have LINE3 set as the default device in the sound card settings in the recording devices tab. In case of any doubts, write to PW Regards.

    http://forums.radioreference.com/voice-contro...-decoding-software/251765-dsd-rtlsdr-vac.html

    And if you have poor hearing at airports and you like to listen, I recommend the website below. There on the left you enter the frequency or port and search. You have files there, thanks to which you can listen online to various airports in Poland and beyond.
    http://www.liveatc.net/search/f.php?freq=126.800
  • #598 15062722
    Skco
    Level 11  
    Ganjor86 wrote:
    What thickness should the walls of the box be and whether aluminum is the best material and whether it is worth using ferrite filters on the cable.


    I tested various options. Including dongle wrapping aluminum sheet, copper sheet, various boxes etc ...

    The best thing in eliminating interference from everything was the solid installation of approx. 1 m of 1.5 mm copper cable to the USB output and removing the metal tip from the USB extension (both on the dongle side)

    The tuner is T2.

    In the pictures, the effects before / after and the applied antenna:

    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 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
  • #599 15062749
    Ganjor86
    Level 21  
    Removing the badge in the usb extension cord did not help, but with the cable connected to the mass of the dongle, it will try. I have also seen a modification involving the replacement of electrolytic capacitors with tantalum ones, and speaking of capacitors, is it normal that electrolytic capacitors heat up?
  • #600 15070494
    Charles Bronson
    Level 14  
    I have a problem installing the tuner as a scanner on PC / Windows 7 64bit. I install according to the instructions from the website: http://www.wykop.pl/ramka/1341289/rtlsdr-czyli-odbieraj-niemal-wszystko-z-tunera-dvb-t/ i nic. I replace the libusb-1.0.dll and rtlsdr.dll files in the SDRSharp directory, I replace the driver with the zadig program and still nothing. When SDRSharp tries to set the signal source to: RTL SDR / USB, it communicates: "RTL SDR / USB is either not connected or its driver is not working properly". What to do? My tuner is:

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

The discussion centers on using inexpensive DVB-T USB tuners, particularly those based on the RTL2832U chipset combined with various tuner modules like the R820T and E4000, as software-defined radio (SDR) receivers. These devices, originally intended for digital TV reception, can be repurposed for wideband SDR reception from approximately 25 MHz up to 1.7 GHz, covering amateur radio bands, FM broadcast, airband, ADS-B, and more. Modifications such as direct antenna connection to the RTL2832U chip pins enable reception of lower frequency bands (below 30 MHz), including shortwave, though precautions against electrostatic discharge and signal surges are necessary. Upconverter circuits based on chips like LA1186, LA1185, and TA7358AP are commonly used to extend reception down to HF and VLF bands by frequency shifting signals into the tuner's range. Various software solutions including SDR# (SDR Sharp), HDSDR, and dump1090 are recommended for Windows and Linux platforms, with driver installation often requiring tools like Zadig to replace default DVB-T drivers with RTL-SDR compatible ones. Users report challenges with driver installation, device recognition, and antenna selection, especially for frequencies outside the FM broadcast band. Amplifiers such as the FP6L and antennas like Discone or long wire are suggested to improve reception quality. Mobile and embedded platforms like Raspberry Pi and Android devices with USB OTG support are explored for portable SDR setups. The community shares detailed schematics, installation guides, and troubleshooting tips, emphasizing the cost-effectiveness and versatility of RTL-SDR dongles for radio experimentation and monitoring.
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