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

And if there is a window sill, you can put something up, I have such an antenna on the balcony on the 4th floor and I receive stations within a radius of 10 to 15 km, you have to combine it in various ways. Recently don_viking has released SDR software for SDRsharper (v0.5V) and it is receiving very well. This is my antenna.

The fact is that the sill is, even a magnet would probably catch oki I will be up to date in October greetings, thank you.

As for the antenna attached to the blue R820T2 tuner, signed with the NooElec logo:

In my apartment, with the window closed (approx. 7 km from the center of Warsaw), I detect:
- GSM band (900/1800 MHz)
- sporadically ADS-B (1090 MHz) - it is possible to receive aircraft locations and information sent by them (the farthest collection was from Ostrołęka, I usually pick up planes heading to Modlin)
- UPC cable audio (quite good sound quality)
- radiotelephones operating at the frequency of 470 MHz (quite faint)
- radios of known services operating in edacs in the vicinity of 459 - 462 MHz (satisfactory reception quality)
- radiotelephones operating at the frequency of 430 MHz (quite faint)
- I very rarely manage to pick up something on the airline
- FM radio in CCIR: here I only catch a few stations and it's rather bad, because I rarely manage to pick up RDS, generally you can hear crackling during reception
- I pick up calls via CB Radio very sporadically
- sometimes it is possible to pick up a radio station from Riyadh on a frequency of around 16.43 MHz

Generally, it is not bad for this antenna, but it is better to invest in better equipment. I did not receive on it:

- transmission in the VHF band (railway, services, 2 m amateur band)
- FM radio in OIRT from neighbors from behind the eastern border (it was possible on old, unadjusted Unitra receivers and a piece of wire)
- transmission in amateur bands 4 m and below

And here I have another application of SDR technology for you. I am posting because nobody on this forum has written about it before. In this link Link it is shown how based on the set: SDR receiver, computer with debian-like distribution + appropriate software, you can decode calls and text messages in the GSM 900 MHz band. Of course, we carry out the entire experiment only for our SIM card, because there is an appropriate paragraph for intercepting someone else's data However, we must first determine the frequency of the BTS downlink to which we connect, our TMSI and our Kc key. Then, based on the system modeled in GNURadio and running Wireshark, we can capture the data. This is what it looks like in theory. In practice, I couldn't even decode the template file provided by the author of this project, even though I followed the instructions provided. Simply, Wireshark did not receive any packets that would allow the SMS to be reproduced, not to mention a voice call. Maybe one of you will be more lucky and he will succeed, and maybe even decode your own file with encrypted voice call and SMS :D

Such a note: do it on Kali Linux version 1.05 or 1.06, because on the newer ones (and on Ubuntu) the whole project will crash at the compilation stage, so you won't even be able to install the appropriate tools. Also switch your phone during the experiments so that it works in GSM mode - most phones from the last 5 years use 3G and 4G technologies by default for voice calls and sending SMS. Of course, I also remind you that the whole game is purely educational and an attempt to decode someone else's transmissions is subject to the appropriate paragraph. Moreover, it would not even be that easy to do - determining the TMSI and Kc of a random person is practically impossible. Apparently, there are rainbow tables somewhere on the Internet (about 2 TB in size) that would allow you to get this information. The only question is whether it is worth taking up valuable space on the hard drive with them? Because it is neither legal nor quick, and the effect will be such that we will find out that some time earlier "Janek" had an appointment with his girlfriend in the park

How strong do you need to have a laptop for the R820T2 dongle?

lantin wrote:

How powerful you need to have a laptop for the R820T2 dongle

And what is a powerful laptop for you? Power is power - my equipment draws 30W and works fine.

Artur k. wrote:

lantin wrote:

How powerful you need to have a laptop for the R820T2 dongle

And what is a powerful laptop for you? Power is power - my equipment draws 30W and works fine.

The number of processor cores and the size of the frames.

On a desktop computer, I have a Core 2 Duo processor and 4GB RAM - it works without a problem. I have an Intel Atom 4-core and 2GB RAM on my tablet - it also works without a problem.

Does anyone have such a dongle for sdr for sale? Of course, 100% functional :)

best regards

Why don't you just want to buy a new one with a guarantee?

I just wanted to ask if someone is in arrears and sells for cheap Of course, I will buy a new one on the Allegro, but I can see that everyone orders on alieexpress and the shipment takes 30-40 days - so and how can I order

tygrysss wrote:

I just wanted to ask if someone is in arrears and sells for cheap

And PLN 40-50 is it expensive? Would you like to buy for 10 or 5 PLN?
I just bought my two on Allegro, one for PLN 40, and the other for PLN 60. I had the goods the next day - I picked it up personally.

But none of those things! Prices on the Allegro range from about PLN 65. I thought that someone would sell here for just like you say PLN 40-50.
If you see somewhere cheaper on the Allegro I will gladly take it - enter the auction number. Just that the shipment is not from China
Because on the Allegro the spread is from 60 to 149 PLN.

Edit: from PLN 75 version T2.

tygrysss wrote:

Prices on the Allegro range from about PLN 65. I thought that someone would sell here for just like you say PLN 40-50.

No exaggeration, the PLN 15 is such a big difference?
You can always wait, the auction at the price you are interested in will definitely appear.

Buddy, no difference, but it's worth asking - and if you had 3 pieces and 1 unnecessary - would you keep in the closet or sell it on the forum to someone who will be useful ?

And with the money saved, you can buy some lumber for the antenna to make it.
In addition, the shipping time, as I said - 30-40 days - flies from China from the seller with Allegro.

I have 5 pieces and no one has ever been redundant

Quote:

radios of known services operating in edacs in the vicinity of 459 - 462 MHz (satisfactory reception quality)

Since when have the known services work in this band?

Hello, I found a website where someone provides SDR. I recorded something like this, what could it be?

For now, I am playing on the Internet - I want to get to know it a bit, and then I will buy something specific :)

best regards

what's 2 = CW
what is = RTTY
As you add frequencies, you will be able to more accurately identify them.

Thank you for your response! Is RTTY decoding legal? If so - what software is recommended by a computer colleague (if any)? I did not have time to save the frequencies. I'm currently listening to 18157.97 on USB.
By the way, when to know what modulation, USB AM or other?

Best regards.

Edit - walrus here, I suppose. 6822.75kHz USB.

Is there any online morsa decoder? Does the study of the walrus remain ?

Tygrysss here is the website of the sdr receiver from Toruń and even the CB band is in Polish and there is an instruction, and there are a lot of these sdr online http://sp2pmk.tvk.torun.pl:8901/

Added after 8 [minutes]:

Maybe I wrote the manual incorrectly in Polish, and you can also listen to the CB band.

Added after 50 [seconds]:

Maybe I wrote the manual incorrectly in Polish, and you can also listen to the CB band.

http://websdr.org/ this site is websdr from all over the world and even satellite receivers.

Thank you very much - you can choose the color you want
How about RTTY decoding?

Buddy TYGRYSSS, you have to search the internet on ham radio forums.

There are many RTTY decoding programs such as MixW, MMTTY, Fldigi. Below are programs for different types of broadcast. They will probably interest you.

Link

kowalsulik wrote:

Quote:

radios of known services operating in edacs in the vicinity of 459 - 462 MHz (satisfactory reception quality)

Since when have the known services work in this band?

For at least a dozen or so years, at least in Warsaw. This is nothing new.

However, I have a few questions about antenna installations used with SDR dongles.

1. I want to connect a dongle to a cable TV installation to see "what's going on there". Can I do it directly, or will the signal from the cable be too strong and it can damage the dongle?
2. I have an antenna that is over 30 years old to receive terrestrial television. It consists of 2 telescopic antennas with adjustable length (max. 1 m each). These antennas are connected with a 300 ? flat cable, which in turn is led through a balun to a 75 ? connector. Will the reception on the VHF, UHF, CB and GSM bands be tolerable on such an antenna (will the signal attenuation be too high), or it is necessary to invest in dedicated antennas with BNC, SMA, SMB connectors (50? ?

You won't find anything interesting in cable. Several wide digital broadcasts from multiplexes. If you give the signal from the socket at home, the level will not damage you. Unless you want to plug directly into the output of a distribution amplifier that serves a larger building :D

Connect this antenna with two telescopes directly with a coaxial cable, bypassing the built-in balun. You can also convert it from 4: 1 because that's how it is there to 1: 1. But as for listening, it is pointless fun.

methyl wrote:

You won't find anything interesting in cable. Several wide digital broadcasts from multiplexes. If you give the signal from the socket at home, the level will not damage you. Unless you want to plug directly into the output of a distribution amplifier that serves a larger building

Anyway, I would like to play it for the sole pleasure of observing the frequency band of cable networks. I understand that then connecting to the dongle, for example, a VCR or an 8-bit computer with a built-in modulator should also not damage it?

methyl wrote:

Connect this antenna with two telescopes directly with a coaxial cable, bypassing the built-in balun.

Do you suggest disassembling these two telescopes and soldering each of them to the core of the coaxial cable and to its braid?

At the antenna input of the DVBT-USB receiver there are LEDs that act as a signal limiter. As long as you don't overdo the given signal, you can take it as a safeguard.
They also perform other functions, but I am omitting it here.

As for the antenna, there is no point in rummaging around with these telescopes. Unless you make it some kind of portable / tourist version that you can roughly tune to the interesting band.
Generally you understood OK. Hot (middle) "coax" to the upper telescopic antenna, screen to the lower or in the case of a horizontally oriented antenna left / right or, of course, right / left ;)

In the place where the antenna cable connects to the antenna, you can put a few turns of this cable about the diameter of a beer can. It will be a kind of balun, but it is not necessary.

I propose to take specific 2 sections of Al or Cu pipe and cut them so that each section is approximately 1/4 of the wavelength of the radio range you are interested in.
The wider the tubes, the larger the diameter, the better because it has a broader range. Make a simple dipole out of it. Attach such something to the appropriate boom and preferably to the roof The higher the better!
Hear more than you need to. It is good to put a few k ohms resistor between the arms of the dipole. The reception will not be affected and will protect against electrostatic, which can charge the capacity of the coaxial cable up to several thousand volts. Discharging such a charge by a dongle is known how it ends.

best regards
SP5MET

Buddy MRQPA see post # 961, this is my antenna on the balcony and above 100MHz it works fine, I receive within 30 km, and even planes can see 1090 MHz in the program adds a program for observing aircraft in your area

Added after 5 [minutes]:

A program for airplanes, my colleague SP5MET as a radio amateur has experience, but sometimes the samorubs work well.

I was listening to the ADSB on a 2m / 70cm dipole. A two-lane one on the roof.
Completely mismatched and theoretically deaf at 1090MHz.
In addition, the attenuation of a 25-meter-long cable is of a better type (CNT-400), but above 1GHz, it already attenuates a lot. The range was over 200-250 km anyway, which surprised me. However, as I saw how many frames per second can be achieved with a simple 1/4 wave GP antenna at 1090MHz connected with a short cable to the dongle directly on the roof, I think it is better to let go of half measures and do it properly.
You can make wide-working antennas but nothing is for free.
The wider the antenna works, the less gain it usually has. Usually quite a bit of a negative. In addition, the angles of radiation of such antennas, and thus the angles from which such an antenna hears, are completely from outer space. Literally and figuratively.
An example is the DISCONE antenna so popular among VHF listeners.
I had it on the roof for 3 years and I had time to compare it to other structures and I will not wear it again. Maybe it's good for RMF-FM and ZETka, maybe AIRBAND hears somehow, but it's a joke in general. Especially "lame" for RTL SDR, because due to the fact that he hears the most in the 88-108 MHz range, it completely clogs the receiver if we have any transmitters of commercial stations in our location. It's hard without the 88-108 MHz traps.