August 21, 2024

Exploring Russian and International Analog TV From Leaky Cable TV Networks via the Airspy Server Network

Thank you to RTL-SDR.COM reader Micha for submitting a story about how he has been able to use SDR# and the Airspy Server Network to explore cable TV stations across the globe via cable TV signal interference.

If you were unaware, the SDR# software from Airspy.com has access to the Airspy Server Network, which is a collection of public Airspy SDRs available all over the world that can be accessed freely over the internet. To access these SDRs simply select "Airspy Server Network" as the source in SDR#, and click on the "..." button next to the server address entry. A map will pop up where you can select from SDRs all over the world.

Using Airspy SDRs in Russia, and in other countries (Guatemala, Brazil, Chile, Uruguay, Mexico, Dominican Republic, Argentina, Indonesia, Vietnam, Micha found that there were several analog TV signals found at frequencies that should not have terrestrial TV signals there. Upon further investigation, he realized that these are actually cable TV signals that are leaking and causing interference across the RF bands. Micha notes that he's also observed how the leaking signals often change in frequency and intensity too, making it difficult to keep track of them.

Combined with the TVSharp SDR# plugin, Micha was able to recover some (very rough) images from these interfering signals. Micha has provided several images shown below that demonstrate Russian cable leakage, as well as for Mexico and Argentina.

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Micha

5 days ago

#259721

On the page "dxinfocentre.com/tv-sam"
It is written that analogue television has been switched off in Brazil. But that doesn't seem to be entirely true...

Micha

11 days ago

#259537

For a few days now, an online SDR has been broadcasting from Novosibirsk/Russia. 
In contrast to the previously known SDRs, with the leaky cable networks, only 3 terrestrial channels are broadcast here. After a long search I found a frequency table. But I'm not sure whether the listed channels match.

Kanal/ Frequenz/ Sender
25 / 503.25 /Freitag! / Werbung MПятница! / реклама M Регион

33 / 567.25 / Disney / OOO Werbung – Region Media Group
реклама OOO «Регион Медиа Групп»

51 / 711,25 / Ю / реклама OOO «Регион Медиа Групп»

Micha

16 days ago

#259412

The live streams shown do not necessarily match the image. The rest should be OK though.
There is probably a time zone offset between the terrestrial TV and the online channel.

Micha

21 days ago

#259224

This is all a big deal. As a technician I throw my hands up in my head, as an analogue TV fan I think it’s great.
So you can roughly summarize that there are leaky cable networks across Russia and disrupting the surrounding area.
The signals emitted interfere and even mix with each other so that identification is sometimes impossible. I’ll even go so far as to say that Ivan, Alexey and Ilya’s online SDRs didn’t think about the distribution of TV signals (at least not primarily).
I’ve spent the last few hours confirming Alexey’s list using live images. I actually discovered a few more streams. But somehow nothing agrees here. This can have several reasons, including time delays, regional programs, or, or. Doesn’t matter.

Digital programs with their 8MHz packages do not fit into the online SDRs. At least not in one go. Because the signals are interleaved, decoding is not possible.
Hello Kirill, it’s nice that you still have analog VHF transmitters. Despite TV DXing, I haven’t met them yet and I’ve never heard of them before.
Thanks Micha

Alexey(@alexey)

21 days ago

#259215

Hello Micha.
Server is still running, I just hid it on the map. The address and port remain the same:

sdr://46.166.94.54:7210/

.
At least 3 providers offers cable analog tv in my home: Siberian networks (ex. Prima-teleset), TTK, SiNT. Perhaps this trio we seeing in the spectrum.

Kirill

22 days ago

#259203

Yakutsk also has a problem with leaking cable TV signals. There are two providers in the city: Beeline (former Helios-TV, also they used to have an analogue MMDS network until 2007) and Transtelecom (TTK). Gelios has a very old and leaky network, it uses frequencies from 111 to 583 MHz, digital TV is located somewhere in the 300-380 MHz area. And here it is in some parts of the city very much interferes with TV-DXing (in the region still operates a large network of terrestrial analogue TV NVK Sakha, by the way, which has several dozen transmitters in VHF Band I), not to mention the reception of Satcom and other satellites. TTK, which has been operating for 11 years, on the contrary has a pretty good network without any Soviet cables (their network does not interfere with reception on the outdoor antenna) Digital TV is clearly a priority for them in terms of cable capacity, they have placed it in the 110-230 MHz area, but strangely one of the multiplexes overlaps the terrestrial analogue channel on VHF ch. R7 (Yakutia24), there are small problems with stuttering of a couple of channels, fortunately they are TV shops. Analogue in contrast to Helios is located from 231 to 850 MHz, the upper part of the spectrum is noticeably affected by LTE, a couple of channels are located in the area of terrestrial digital TV, they are impossible to watch. What is rare for cable networks absolutely all analogue channels use the SECAM colour system. No one transmits radio in cable networks anymore, only via DVB.

Micha

22 days ago

#259202

Hello Alexey, 
I have now created a few screenshots quickly and will evaluate them shortly. I've noticed that here and there, double, even triple tones disturb each other. Also that the cable networks are used differently.
 Now that I can put Ivan's and your information together, I may have found an explanation for how some TV sound can also be found on military satellites. I realize that some of the TV sound is sent in a targeted manner, but some of the signals sound like radiation. After your explanation that there are still some programs in even higher frequency ranges, it is not completely impossible that one or two sound signals get lost there, or a harmonic one. It is completely clear to me that there is a frequency offset between uplink and downlink.  For a while, the entire Mil-Sat spectrum was transmitted via WebSDR. But this SDR was switched off. Unfortunately, a parallel tone comparison is no longer possible.
gruß Micha

Ivan Abilev

22 days ago

#259196

Our cable networks are holey 🙂 cable network #2 was built in 1996 and they haven’t changed cables or done maintenance since then. After all these years, the cables at the top of the range show very poorly, but the bottom of the range still works well. They fixed this problem with a powerful amplifier that boosts the high frequencies to a moderate signal and the low frequencies to a crazy level that can be heard far beyond the cable. This cable is owned by the giant Rostelecom, who bought it along with the internet service provider. 90% of subscribers do not pay for its operation, and I hope that soon it will be completely disconnected in favor of IPTV.
The second Intersvyazi network was launched in 2015, and it works differently. Optical cable is brought into the house, and from the telecom equipment comes coaxial with a full set of frequencies. I don’t know exactly how they assemble this pool of frequencies, but there is virtually no interference from them. But they also plan to do away with analog broadcasting, leaving only DVB-C. Unfortunately, they interfere with FM reception with their internet.
Twisted pair as a huge conductor gives interference in all bands in the form of frequencies with hum. In general, the situation is the same all over the country. Cable networks are wearing out and the TV charges do not match the quality, people are disconnecting it or not paying for it.
In some cities FM radio still works on cable, just bring the receiver to the cable and it will Catching radio stations

Micha

22 days ago

#259195

Thank you Alexey for your information. 
It looks like I can expand and correct my Achinsk table. Thanks.
It quickly became clear to me that the TV signals could in no way be regular terrestrial broadcasts, but I couldn't imagine how big the problem of leaky cables was. 3 cities in these distances, with the same problems, on this scale?  As a radio and television technician, part of my job is to repair leaky cable systems. Of course there have been similar problems here in Germany, but not on this scale and with the introduction of digital TV and FM switching off (in cable systems) this problem has almost been eliminated.

I know from the press that UHF TV is still broadcast in Russia. Also that more and more programs are broadcast digitally or via the Internet. The frequencies received do not fit into any internationally established terrestrial grid and I think that Russia is also bound to international agreements. OK, these interferences don't spread to neighboring countries and only the online SDRs reveal this interference. Of course, here I can only access and report on the frequency range fed in.

My own SDR (Noelec NE SDR smart XR) also likes to react to strong VHF/FM signals, despite the upstream filter. This problem is annoying and mainly affects the aviation radio range (109-139MHz). Otherwise, this device is worth every cent and is a great receiver with the appropriate antennas (terrestrial and satellite).

Thanks Micha

Alexey(@alexey)

22 days ago

#259189

Hello. I’m SDR receiver owner from Achinsk, Russia. Those signals are received from ISP’s cable analog television networks. Most of the them duplicated in DVB-C format and many other providers offers TV via internet connection (IPTV/OTT). The only one TV station currently broadcasting on terrestrially in analog format in my city is сhannel 52, U-TV. Antenna connected to receiver mounted on roof of a residential building. Under the roof there is an attic with the ISP’s equipment and bunch of different cables (UTP, coaxial, etc). Those cables simply lying in the attic for many years and aren’t protected mechanically; many of them have damaged insulation and shielding. That’s why they emit so much signals.
I’ve added some frequencies to your list, if you interested. On some frequencies signals from different providers are mixed, see coms after ‘/’
There is much more channels can be received on higher frequencies, but my receiver (Airspy HF+) works only up to 270 MHz. Other receivers (RTL-SDR, RSP1a) are overloaded by FM band (88-108 MHz) radio signals when connected to an ext. antenna.

111.265 117.764 Первый канал(Perviy kanal)
119.280 125.768 Россия 1(Rossia 1)
127.315 133.753 Матч!(Match!), 133.755 Первый канал(Perviy kanal)/ audio carriers overlap from different providers
135.275 141.773 НТВ(NTV)
143.267 149.755 Россия1(Rossia 1)
151.232 157.738 5 канал(5 kanal)
159.255 165.754 Матч!(Match!)/ there is also much weaker signal from another provider, I can’t identify it
167.243 173.727 Россия 24(Rossia 24), 173.755 НТВ(NTV)
175.254 181.727 Первый канал(Perviy kanal), 181.754 5 канал(5 kanal)
191.254 197.754 Матч!(Match!)/ there is also weak carrier from another provider, I can’t identify it
199.206 205.723 НТВ(NTV)
207.255 213.755 Россия 24(Rossia 24), 213.777 5 канал(5 kanal)
215.255 221.755 Культура(Kultura)
223.255 229.734 Россия 24(Russia 24), 229.755 Карусель(Karusel)
231.255 237.755 ОТР(OTR), 237.772 О!
239.254 245.748 ОТР(OTR), 245.755 ТВЦентр(TVCentr)
247.225 253.724 ТВЦентр(TVCentr), 253.754 РЕН ТВ(REN TV)
255.267 261.767 ТВ-3(TV-3)
263.240 269.740 Спас(Spas), 269.755 СТС(STS)

Micha

24 days ago

#259144

Hi Ivan
Thanks for your signal. I am convinced that the bandwidth is not that important here. You can only receive picture or sound anyway. You won't get the required 8MHz with this technology anyway. Please try reducing the bandwidth. The TV plugin works from just a few KHz. Perhaps you can attenuate the direct cable connection or connect it with 2 wires (2 antennas) and thus simulate a radio link. Maybe after that the signal will be snowy but more visible. 
Thank you very much for your efforts
thanks Micha

Ivan Abilev

24 days ago

#259143

I just checked. Indeed, it does not work through Spy Verter. It is necessary to enable full IQ and minimum frequency 2.4 MHz or better 4.8 MHz. Then it probably won’t work.

Micha

24 days ago

#259142

Thanks for your invitation, but see the problem. 
The signal is great, but the images are heavily rasterized. So I can't find anything out...
Noisy images are easier to identify.

Micha

….ooh server is busy…

Ivan Abilev

24 days ago

#259141

Connected. Come in.
sdr://178.46.161.201:5560/
Hopefully the Airspy mini will suffice. R2 is at a remote site.

Micha

24 days ago

#259140

ooh, exactly

Micha

24 days ago

#259139

Hello Ivan. 
Your information is great, as is your offer. I would never have looked for TV programs in the FM range (except in the fringe range up to 88MHz), 

My plan is to make a small documentary about analog television in Russia and South America. Your offer is very helpful.

OK, an intended signal activation would be a great thing and, above all, unique in SDR online history. I guess this has never happened before (this week would be great).
But I'm afraid that a public date will attract thousands of people and then I won't get a chance...

I can well imagine that analogue television is no longer popular, but that's not the point. Rather, it's about finding the last remaining channels. The discoveries about online SDRs are pure coincidences. In this context, it is also a shame that some people in Central and South America were only online for a very short time. Maybe some of your people will get in touch

Thanks Micha

Ivan Abilev

24 days ago

#259138

In Troitsk you receive signals of 2 cable networks at once. Intersvyaz and the 2nd local ‘Untitled’. Somewhere they work on the same frequencies, somewhere they overlap.
There are 3 cable networks in Miass, and one of them is Intersvyaz, whose frequencies coincide with Troitsk. So, in ‘Intersvyaz’ the sound track works with an offset of 150 kHz. For example, Channel 4 operates on the frequencies 91.75 and 91.5 MHz.
Generally, there are 20 compulsory channels in Russia
and this list of channels is the same everywhere. It makes no sense to collect information on cable networks. The same channels operate on different frequencies. But I can connect cable network ‘Intersvyaz’ for 1 day or 2 days on the server and you can watch and record the necessary information yourself. This network works all over our region.
In Russia, up to 90 per cent of TV viewers watch TV via cable. There can be up to 5-6 networks in one city, and even the communications regulator does not control them. Analogue television works on a residual principle, it is not watched at all.

Micha

24 days ago

#259136

Ivan Abilev/ Troitsk

Bild      Ton     Ton
           65,500 65.750
77.153   83,500 83.750
111.256  117.500 117.750
119.258  125.500 125.750
127.253  133.500 133.750 (Testton) Kanal Kultura
135.258    ?      ?

Ilya Pastukhov/ Miass

Bild     Ton 1   Ton 2
111.185  gestört 117,750
119.267  125.500 125.750
127.254  133.500 133.750 (Testton) Kanal Kultura
135.227  141.500 141.750 Rossija 24
143.248    ?          ?

Anonymus/ Achinsk
Bild     Ton 1    Ton 2   Programm
111.265 117.764
119.280 125.768
127.315 133.753
135.275 141.772      Kanal Kultura ?/ Nachts Testbild/ Test-Ton
143.267 149.757      Telekanal Rossia ?
151.232 157.738
159.255 165.754
167.243 173.727 173.755 unterschiedliche Töne
175.254 182.727 181.754
191.254 197.754
199.206

Micha

24 days ago

#259131

Hello Ivan!
Thank you for answering. Finally I get one of you three reached. Unfortunately, the email address I knew was inactive and I haven't been able to reach you yet. Your offer is worth its weight in gold. Please give me information about the other programs and frequencies that I have not been able to determine yet. A live stream comparison would be great, but I don't have the opportunity because the programs are blocked here. Only Rossia24 and Kanal Kultura have been identified. In addition, the signal quality fluctuates extremely, and you change your frequency range every now and then.

At least I'm glad that my assumption is correct because I'm familiar with this problem from the analog TV era. 
Thank you, Micha

Ivan Abilev

24 days ago

#259130

Hello. What exactly do you want to know? The servers of Troitsk and Miass are installed in a residential building, and the cable TV signal penetrates through the terrestrial antennas. You got that right. Signals from these cables on SDR can be received at a distance of up to 1 kilometre from residential houses

Micha

28 days ago

#259048

Maybe I can reach a few SDR providers this way. Many of you don’t have an email address or don’t respond when I write to you. Often your SDRs are only online for a few hours or days and there is little time (or lack of language skills) to identify the TV channels. The Internet mainly contains information about digital offerings. The same transmitters are used here, but different frequencies are active. You could compare the channels in the live stream, but geoblocking makes it impossible (except Rossia24). Another hurdle is the separate reception of image and sound.
I get important but incomplete information from:

https://www.dxinfocentre.com/tv-sam.htm
https://en.wikipedia.org/wiki/Pan-American_television_frequencies#Terrestrial_television

All TV channels from the countries in Central and South America can be found in Wikipedia.

I need information from:

Ivan Abilev, Troitsk, sdr://178.46.161.201:5555 / Russland
Anonymus, Achinsk, sdr://46.166.94.54:24816 / Russland
Ilya Pastukhov, Miass, sdr://178.46.165.91:5556 Russland

Edurardo SDR, Santo Dom, sdr://179.132.220:5555 / Republica Dominicana
CE5AUC-2-RTL-SDR, SDR://186.103.216.243:20003 / Chile
anonymus, Valparaisosdr:// 181.206.120:5555 / Chile
anonymus, Santiago, sdr://201.241.85.46:5556/ Chile
sdr://186.54.21.14:5555 Argentinien
Lu8ML- Airspy Mini, sdr://190.177.187.122:5555 Argentinien
ReneDXRadio YouTube channel- Airspy HF+, sdr://187.145.12.40:5557 / Mexico
Naglio Braga VSN- Airspy R2, Tower do Cerro Grande -Cangucu RS, sdr://177.10.119:5556 / Brasilien
LWB [email protected], sdr://45.160.148:5555 / Brasilien
Jorge Blumenau-SC Brazil- [email protected], sdr://210.34.189:5555
Alonso Franco (anonymus), RTL-SDR, sdr://181.206.23.16:5555 / Columbien
[email protected], Dolores, sdr://167.57.44.147.:5555 / Uruguay

SDR addresses are constantly changing!!

Allan, from Guatemala, willingly sent a TV channel/frequency list – thanks for that.

Micha

Iván

Reply to Micha

16 days ago

#259411

Hi Micha Iam the owner of the spyserver in Argnetina LU8MIL. Nice see that you used is some funny way. [email protected] if you need something

Micha

28 days ago

#259047

Hi Mario.
Only a small part of the pictures and information is published here. OK. They are just noisy images and it is difficult to determine the real channels. This is because there is no longer any new information on the subject of analogue TV for good reason. In the future, the channels will gradually be replaced by digital channels. That's why we only report on the new technology. So far I have only found sparse information on the internet. These analog programs are the last of their kind and the onlineSDRs are not originally active to transmit these programs, but rather radio and communication are transmitted here. The TV programs are an "unintentional" by-product and were only discovered by chance. I wasn't aware that there were so many in total. With even more SDRs online, there should be even more programs worldwide. The phenomenon and mystery remain the 3 Russian SDRs because cable frequencies radiate into the SDR antenna, all 3 have the same problem and some live 2000 km apart (according to Google Maps)
Greetings Micha

MARIO

Reply to Micha

24 days ago

#259137

Thanks Micha. Here in the USA, analog TV ended in 2009. However digital TV stations from long distances can be received depending on weather conditions. I’ve logged DTV from as far away as Virginia. When your country switches over to all digital, TV DX is possible. Have a nice day Micha.

MICHA

Reply to MARIO

3 days ago

#259755

Hi Mario. TV DX macht spass, ist jedoch durch Einführung des digitalen Signals erheblich schwieriger geworden. Wegen der großen Bsndbreite und der Verschachtelung der Signale, ist ein Empfang über das onlineSDR Netz wahrscheinlich unmöglich. Schade! Da wären viele digitale Programme zu empfangen.
Gruß Micha

Mario

28 days ago

#259046

Now that’s really neat.

Micha

29 days ago

#259023

Thanks for publishing.
But a few explanations seem necessary. Only with the Russian SDRs do the programs radiate into the antenna. I think terrestrial broadcasting is unlikely because the TV programs also mix with terrestrial radio signals, eg AERO-Voice and weather satellites (NOAA). The antenna must therefore be attached to the window or outside. A leaky cable network can certainly radiate in here, but a weather satellite in the indoor area is unlikely to. The only strange thing is that all 3 providers in the cities of Miass / Achinsk / Troitsk
have the same problem. After all, there are up to 2000km between the cities.
In South America these are regular terrestrial broadcasts. But be careful! An SDR in Brazil receives the programs from Urugay.
The whole story is difficult to understand because some SDRs are only online for a short time, constantly change the antenna or gain, are not designed for TV reception at all and terrestrial TV is switched off (e.g. Indonesia)
greetings Micha

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