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

Sumar wrote:

sluchacz/radioscanner.pl wrote:

The new version with spaces (tested on SDR # rev 1457) of XML generated a script, please be understanding if there are errors (and reporting them)

I converted to the format used by SDRUno as if someone needed it.

Hi, how to get virtual radar server to generate antenna coverage line? I set my location in the program and assigned it to the receiver and that has not helped yet. PS. tests with a 9-element collinear antenna. For this there will be an amplifier soon.

9-element collinear antenna + amplifier = 90% damaged receiver or, in better case, only clogged, which will result in fewer packets. You cannot jump over the range dictated by the curvature of the ground.
All you need is a collinear antenna connected with a short good cable to the receiver, without any preamplifiers.

If there is a BTS nearby with LTE hanging - your receiver will go deaf. I once put a receiver with a collinear antenna 100m from BTS Play for a test - it became deaf, it was enough to walk behind an obstacle such as a building and cover the BTS signal - it gave full range in the opposite direction.

You turn on the range graph in the browser by clicking Menu> Receiver Range> you choose from what ceiling.

However, I will approach it with my experience. First, you can limit in SDR # options how much the receiver "hears". Secondly, you can use a regulated power supply. Third, need is the mother of invention. Fourth, the analyzer shows whether the amplifier is excited from signals of other frequencies. Fourth, using an amplifier wisely does not mean that you will amplify the noise and the signal is still unreadable. With this post, I wanted to correct some information that appears here often. For me, each antenna has an amplifier. From tv, from probes, from digital radio. In any case, the antenna works better than on the symmetrizator itself.

I've been testing Ant recently. VHF 64-72MHz dipole + heat sink, third heat sink inside on
band 70 cm, I installed a L 70CM rod and RTL 2832 fc0012 dongle
various signals in the 432-435MHz band, the signals can be opened with a remote control from the mobile

Speaking of the antenna for the 64-72 MHz band: do you think that in Warsaw it is possible to passable and continuous (not only in tropo time) reception of radio stations in the OIRT band from neighboring countries such as Russia, Ukraine, Belarus and Lithuania?
I have a Ukrainian friend who rents an apartment in Warsaw and who would like to listen to the radio from his website this way. Why this way, when it is possible via the Internet, satellite or on long, medium and short wavelength? And because the owner of the apartment did not agree to a permanent Internet connection (and Internet radio consumes a lot of transfer on mobile internet, besides, streams can "hang") or to a satellite dish, while listening to the radio on long, medium and short waves is known limitations such as sound quality and in many cases the ability to only listen at certain times that are dependent on solar radiation.
I became interested in this topic a long time ago and I tried to receive such stations on taraban (before I tuned it), having a half-dipole for the OIRT band as an antenna, but the only thing I was able to pick up were "SLRs" of the strongest local stations from the 87.5-94 band . 4 MHz. I would like to point out, however, that the tests were conducted in quite poor conditions - the ground floor, a place surrounded by tall blocks and trees, no amplifier (which would probably only strengthen the "DSLRs" with CCIR even more).
Some time later I returned to the topic and tried the reception on the same antenna on RTL-SDR and in slightly better conditions - second floor, a lot of free space. Only occasionally I was able to pick up are calls from hams in the 4m band.

So my question is - is it worth trying and if so:
- what antenna should be used (or rather how many elements should it have, because it will almost certainly be some Yagi)?
- should you use an antenna amplifier?
- how high should I place the antenna?

A friend has a tuner with double VHF (some Sony made for the post-Soviet market), it is also resistant to "SLR" cameras, because the intermediate frequency conversion is already done with a microprocessor.
I admit that I would love to pick up these stations on RTL-SDR myself.

RTL-SDR will easily receive OIRT frequencies.
The Japanese 76-90MHz band received normally.
Anyway, I can check with a RF generator how it works in the whole OIRT band.

I asked a Belarusian friend that he said that they have not broadcast in the OIRT for some time.
Although he is from Brest, I do not know if this is the case in the whole area.

According to this thread, OIRT transmitters are also turned off.
https://www.elektroda.pl/rtvforum/topic2461951.html

Although it is written that it is public. Maybe the private ones still work.
You would have to check the position and the output power.

mrqpa wrote:

Internet radio uses up the transfer of mobile internet terribly

A very interesting topic, but I have to refer to it. Taking the quality of 128 kbps and listening 24 hours a day, you will get less than 40 GB in a 30-day month. In addition, the average price is PLN 0.30 per GB and comes out of PLN 12 per month. Horrible?

Or take Aero2 and listen at will.

Selecting VHF at such a distance is not an easy matter.

pawelr98 wrote:

RTL-SDR will easily receive OIRT frequencies.
The Japanese 76-90MHz band received normally.
Anyway, I can check with a RF generator how it works in the whole OIRT band.

I asked a Belarusian friend that he said that they have not broadcast in the OIRT for some time.
Although he is from Brest, I do not know if this is the case in the whole area.

According to this thread, OIRT transmitters are also turned off.
https://www.elektroda.pl/rtvforum/topic2461951.html

Although it is written that it is public. Maybe the private ones still work.
You would have to check the position and the output power.

The fact that it will easily receive OIRT is known. My point is whether a stable reception is possible a few hundred kilometers from the transmitter.
Belarus broadcasts only public stations on the OIRT. Ukraine and Russia different. In addition, 2 stations in Lithuania, several stations in Moldova, Georgia, Armenia, Tajikistan and Turkmenistan. I did a very thorough research on this topic based on the lists of transmitters and official websites of radio stations and this is how it looks.
This year, in Ukraine and Russia, the process of switching off analogue terrestrial television is also being carried out, which is postponed from year to year, and this time it is probably the end, because there are advertisements in the media and public communication.

Sumar wrote:

A very interesting topic, but I have to refer to it. Taking the quality of 128 kbps and listening 24 hours a day, you will get less than 40 GB in a 30-day month. In addition, the average price is PLN 0.30 per GB and comes out of PLN 12 per month. Horrible?

There is this type of problem with streams that they can clip with a very large number of users (or even be unavailable for this reason - try listening to Three during the week in the morning hours - a difficult task). Besides, my friend uses up a lot of bandwidth anyway, so why would he need even more?
And above all, making an antenna installation for such reception is not art for art, but a practical test of your skills and broadening your knowledge.

pawelr98 wrote:

Or take Aero2 and listen at will.

It is not convenient because you have to fill in a cap every hour, besides, I have no idea if foreigners can register for it.

I think it will be best to check what amateurs write about 4m reception.
You will probably find the entire description of the antenna, the equipment used or even the range.

There is another online alternative.
Attaching to SDR online in Ukraine and taking a signal from there.

And foreigners can get Aero2.

pawelr98 wrote:

I think it will be best to check what amateurs write about 4m reception.
You will probably find the entire description of the antenna, the equipment used or even the range.

There is another online alternative.
Attaching to SDR online in Ukraine and taking a signal from there.

And foreigners can get Aero2.

As in my opinion, the antenna for ham radio applications in the 4m band is completely different than for receiving OIRT radio (although it is the same band). Once it works with a more narrowband (~ 70 MHz), while the full OIRT was 65.5-74 MHz at the end (for some unknown reasons, most of the newer receivers with this band have the range from 64 MHz, although no one is below 65.5 MHz. transmits), and two that for HAM applications, the antenna is connected with a cable with an impedance of 50 Ohm, while in radio broadcasting is 75 Ohm (or 300 as the old receiver).
Attaching to SDR in Ukraine would certainly avoid (to some extent) falling streams, but on the other hand, it still does not solve the problem of increasing data transfer.
As for Aero2 - if I'm not mistaken, this year was supposed to be the last year of free use (the contract was extended from 2016 to 2019).

A couple of the strongest stations from the direction of Belarus - frequencies detected by the automemory method.

65.90 MHz
66.15 MHz
67.05 MHz
67.85 MHz
69.00 MHz
71.60 MHz

ps
I strongly advise against RTL-SDR for broadcasting matters, because the interference effects will be tragic.

In Aero2 there are packages for 5 PLN 3gb and the possibility of ordering from 1 to 3 packages at the same time.By having purchased packages, the system automatically notifies the consumption of the package. in from youtube

@flinc
Google caches itself locally. This is called google world cache or google local cache and it works so that there are google servers in the server room that cache different "jutubes" locally, if you are on a network that is close enough to such google cache, google services will be banging. If the aero is exchanged with someone who has such a cache at home, it will be fast, from what I associate it in Neostrada, it is already flying through Franfurt.

I have a few questions related to Radio SDR
1. Can an SDR radio with a transmitter be easily (software) converted into a DDS generator?
2. Can you use it as spectrum analyzer.
3. What are the benefits of a higher sample rate (Bandwidth).
4. Which gives a higher resolution of the ADC converter. Most have 8 bits, but I've seen 14 bits.

flinc wrote:

In Aero2 there are packages for 5 PLN 3gb and the possibility of ordering from 1 to 3 packages at the same time.By having purchased packages, the system automatically notifies the consumption of the package. in from youtube

Tommy82 wrote:

Google caches itself locally. This is called google world cache or google local cache and it works so that there are google servers in the server room that cache different "jutubes" locally, if you are on a network that is close enough to such google cache, google services will be banging. If the aero is exchanged with someone who has such a cache at home, it will be fast, from what I associate it in Neostrada, it is already flying through Franfurt.

The topic finally went to the Internet, but I would still like to try remote receipts on VHF (mainly OIRT, but CCIR can also be), because it is an interesting issue. What is the real maximum distance from the transmitter to have stable and constant reception (by this term I understand that the radio station can be received at any time, in stereo, without crackling and with RDS)?
I have self-made half-dipole antennas (for the CCIR and OIRT bands) and with CCIR it is about 50 km, but I note in advance that it is a two-element antenna, in addition, located in an unfavorable location.
With this station performed at OIRT (in the same way) from across the eastern border, I never managed to pick up (I live in Warsaw), sometimes only local hams in the 4m band. Once I had a situation that during the tropo, a little below the OIRT band (around 63 MHz), I was able to receive a signal transmission from the studio to a transmitter of an Italian radio station (in Italy, frequencies from 50 to 87 MHz are used for this purpose). It is so strange that such broadcasting is carried out with very low powers, lower than the transmitters of the stations in the OIRT band across the eastern border, which I have never been able to receive. As you can see, electromagnetic waves, contrary to commonly accepted theories, can be unpredictable.

Status of VHF stations currently broadcasting UKW BRECHT page or enter in G ... le VHF radio stations many threads open in the topic

mrqpa Hi, I think 50km is not much. I recently built a 1090 MHz collinear antenna and set it up at the highest of all antennas, about 6-7 meters above the ground. Out of curiosity, I checked how it deals with other bands and, for example, I came across a radio from Kielce (174 km from me). Maybe not stereo and RDS, but reception was very correct. A different situation. I built a 5-element antenna for the VHF band with the help of the local forumers. It is put on only on Fridays at night and it is removable on Saturday, so I adapted the handle on the mast so that it was easily accessible and that the assembly could be done without tools. I receive the signal from Warsaw, and more specifically, it is about DAB +. On the antenna-transmitter line there are certainly obstacles in the form of nearby buildings. On the antenna with a balun, I received a signal from SNR 12db. After using the antenna amplifier in the same location, it was already 22-25db. In my opinion, you should try to build a half-wave yagi antenna with a loop dipole. Maybe it will be large, but it will bring tangible benefits. Second, at least try an amplifier. Be sure to use a regulated power supply as overload can occur. In SDR settings, rather do not use the highest possible gain.

You won't be able to do the VHF-FM DX DX equipment on this equipment, because one station at + 20dB is enough and in the frequency settings you have to look for a free space so that they do not overlap, because the equipment cannot completely cope with suppressing mirror frequencies. If you have a few such stations (and you certainly have them), the more the band will be cluttered with wide-spectrum SLRs (the bandwidth of such a VHF-FM station is about 100kHz) and in addition the AGC does not work properly when RTL-SDR seeing such a SLR "thinks" that he sees the signal being received. And you can forget about proper DX listening. Get yourself a real decent tuner for these purposes and give it up. Personally, I recommend the ST-S311 unique in the range of Sony tuners on the extremely rare third-order NARROW filter with a sensational RF selectivity. I recommend it for the competitive DX listening. It can be purchased on the Allegro for a cap of pears.

So where do youtube recordings in the Netherlands and the UK during tropo are received from stations broadcast in OIRT?

Propagation of this type is unknown and no one will answer this question unequivocally. During the tropo, strange things are observed, such as weakening of the signal of local stations. Recently, when it was in the fall, the signal of the local repeater completely disappeared for me. The reason for this situation was the abolition of the phase of waves reaching me from two different directions.

@mrqpa
These Italian transmissions below VHF or the reception of VHF OIRT stations in the Netherlands and Great Britain are not tropospheric propagation, but ionospheric (sporadic Es / e, es / e sporadic), which is a completely different type of propagation. With this type of propagation, apart from the equipment, a lot of ... luck is also important. And the signals can be so strong that you can hear them also on less sensitive receivers. The main thing is that in such a receiver strong signals do not "spread" strong stations over the entire scale.

In addition to tuners, some FM DXers also use car receivers (due to their usually quite good parameters related to the conditions of their use).

Indeed, RTL-SDR does a poor job of receiving weaker stations.
Today I checked it and with the "AGC Tuner" option turned on, a strong station (in my case Radio Plus at 96.5 MHz) "clogged" almost the entire range. Disabling this option meant that the situation returned to normal, but unfortunately it was not possible to receive these weaker stations at all, and so it was possible in a trace.

I did the tests by the way - I made a TV antenna for one of the family members and I wanted to see how it would perform on other bands. Surprisingly, despite the different destination band and polarity, it receives noise-free stereo and radio rds, plus the aviation band, cb, security, railway, ambulance and everything above 400 MHz (taxi, energy, 433 MHz, 70 cm, pmr, police in edacs).
The antenna was made as passive and directional (broadband dipole at 191.5 - 770 MHz) from the elements I had at hand (2 mm steel wire cut to size, balun for channels 1-69, coaxial cable, junction box). The only thing I had to buy was an LTE filter to reduce interference from nearby base stations.
In that case, it will be used not only to receive TV, but also radio. That would be too much for old Taraban anyway.

At this point, you are talking about something else other than me before. Ie. about two things. The first is the noise generated at the receiver's input, the greater the lower the frequency of the generator (LOCAL) relative to the reception (TUNE). They can only be detected after spectral analysis in at least two or three different generator settings by comparing the signal strength or by simply moving the graphical analyzer with the mouse. These are intermodulation distortions usually (but not necessarily) caused by the nonlinear imperfections of the integrated (pre) amplifier that each any amplifier generally insignificant. If by moving the analyzer (say to the left) the signal follows the alignment in the same direction (ie to the left), you can see the intermodulation distortion of the device. Importantly, these are the non-linearities of the so-called low rows. In this case, they are enormous - to the extent that they completely cover the weaker stations. If, by shifting the analyzer as above (i.e. to the left), the signal goes in the opposite direction (i.e. to the right), this is the RF interference distortion, the so-called the mirror frequencies I mentioned earlier. The second thing you are talking about is the usual clipping, which is quite easy to get rid of by setting around - (minus) 10dB to the highest possible setting. Below is the RTL-SDR intermodulation distortion using graphical analysis, where you can see the non-existent station marked in yellow. That is, the spectrum of the station on this frequency is not actually present in the device. You can see how the spectrum suddenly disappears during tuning at the highest LOCAL setting (near 108 MHz), which is unfortunately an unpleasant sign that the interference / interference takes up / takes up almost the entire tuning range of the device.



I am talking now about something that has so far been found with great effort in specialized literature. And you can say unattainable for the average person. Meanwhile, they can be due to the imperfections of the RTL-SDR. Importantly - IMD distortions have always been present in electronics !!!

ps
For information, let me add that point IP3 capture concerns essentially common but completely separate higher order nonlinearities!
It is used as one of the leading parameters for technical control of receivers.

Hello everyone,

Can any of my colleagues advise me what is wrong with my configuration, that DSD does not decode DMR for me?

I am attaching a few photos from my configuration and the error I am seeing.

You pick on the microphone, and Vac comes out. This is how it is supposed to work.
Besides, I don't prefer to "sew" DSD into this plugin. And there will be people like me here.
You definitely need to change the Output to 1, because these are the speakers.
And the rest I do not know how is configured there.
Besides, Step is not 10, but 12.5. Bandwith is not this one either.

Thanks for the hint.

How should the bandwidth parameter be set?

Did I choose the virtual cable correctly?



What settings should I send for verification?

The optimal bandwith for a given system is here: https://www.rtl-sdr.com/tag/signal-identification/
In the case of DMR, it is 10,000 Hz.
I don't know if you chose VAC correctly or not, because it depends on how you configured it.
If, according to this: https://www.elektroda.pl/rtvforum/topic3182271.html, it should be Line3.
I am set like this:
a) Audio
- samplerate: 48,000
- input: [MME] audio mapping Microsoft - Input
- output: [MME] Line3 VAC
b) DSD Interface:
- you check Enable aux audio output
- the output level slider between the second and third bar
- audio device: [MME] Line3 VAC
And then I run .exe DSD
Pros:
- nothing growls from the speakers, because here the sound itself is decoded
Minuses:
- the analog should be listened to through KG-Tone - if you leave it running while decoding the digit, it will be a drone of the digit

For mrqpa
In AGC, uncheck AGC = increases RTL sensitivity

Added after 40 [minutes]:

For mrqpa
In AGC, uncheck AGC = increases RTL sensitivity

Added after 1 [minutes]:

For mrqpa
In AGC, uncheck AGC = increases RTL sensitivity
and USE HANG