Re: Help in identying a jamming signal

[Undescribed Horrific Abuse, One Victim & Survivor of Many]

Hi,

I'm not a radio engineer and don't use gnuradio much but used to think
about these things for hobby hacking.

Thoughts:
- Recording from multiple antennas simultaneously could:
  - provide for separating it from the signal using a blind source
separation approach
  - give more information on the direction of the noise
- Integrating a signal pulse period to gain detail on it (like with
pulsars or van eck phreaking) could reveal things, such as what it is
doing if it is a powerful unshielded electronic device

Incidentally, I'm quite curious how to do those two things with gnuradio.

On 9/27/23, Daniel Estévez <daniel@destevez.net> wrote:
> Hello,
>
> Taking a quick look at your recording, I see some kind of pulsed signal
> that follows a regular pattern. The signal is on for a period of ~548
> usec, then off for two periods of this duration (~548 usec per period),
> and then the same repeats forever (one period on, two periods off). This
> doesn't look like anything that would remind me of LTE or 5G.
>
> A wider recording might give more clues, since, since this pulsed signal
> appears to be much wider than 2.5 MHz. If you have access to an ADALM
> Pluto, you could use Maia SDR (https://maia-sdr.org/) to record. This is
> exactly one of the use cases I had in mind when I started the project.
>
> Best,
> Daniel.
>
> On 27/09/2023 13:21, veso266@gmail.com wrote:
>>
>> Hello there all, I hope someone can help me
>>
>> I am trying to watch some television on CH47 (679.25Mhz)
>>
>> I am in Slovenia and I am trying to receive and watch Federalna
>> Televizija transmitting from Bosnia and Herzegovina (BiH)
>>
>> But there is very anoying signal bothering me, you can see the problem
>> here: https://youtu.be/wt4vEfu7yEI?si=XDQ8wQ-rK-lb8LMW
>>
>> Instead of seing PAL and hearing sound, I see this anoying lines and
>> hear digital data :(
>>
>> So I decided to bring my Airspy R2 to visually see and record some IQ
>> data on whats going on
>>
>> So this is what I recorded:
>> https://transfer.sh/dMhDtqnodK/baseband_679250000Hz_14-23-42_26-09-2023.wav
>>
>> Center frequency was 679.25Mhz but sadly I was only able to record about
>> 2.5Mhz of Bandwith, because my phone could not handle full 10Mhz
>>
>> As you can see PAL was bearly able to get through this jamming signal
>>
>> At first I thought it could be 600Mhz 5G NR which is sadly right where I
>> want to receive  (663 – 698 Uplink, 617 – 652 Downlink), but thats only
>> for US, not Europe
>>
>> The next suspect could be 5G Extended Lower SMH (which has downlink from
>> 698 – 716) but its 20Mhz above my signal, PAL only needs about 6-8Mhz so
>> this should not be a problem
>>
>> Then I thought maybe LTE Lower SMH on 700MHz could be the culprit, which
>> again doesnt make any sense (Downlink on 699 – 716Mhz)
>>
>> I hope something could be done
>>
>> At least to figure out what signal that is so I can complain to relevant
>> local authorities
>>
>> I am there for a 3 more days, so if needed I can do more messurments
>>
>> Sadly I only brought Airspy HF+, and Airspy R2 with me nothing more
>> capable bandwith vise
>>
>> I also have Samsung Galaxy S10+ if it can maybe help in messuring LTE
>> signals somehow
>>
>> Thanks to everyone for anwsering
>> --
>> Sent from myMail for Android
>>
>
>