I have made some measurements of the ambient electromagnetic noise during car drive.

?Happy New Year to everybody. ?
Chavdar LZ1AQ

On Tue, Jan 4, 2022 at 05:30 PM, чавдар левков wrote:

I have made some measurements of the ambient electromagnetic noise during car drive.

Hi Chavdar,

A very interesting post, and something I would like to be able to do better.

If you could capture GPS co-ordinates you could produce a heat map, something like this on one of my webpages.



I used a mapping add-on in Excel to combine the data and overlay it on the satellite map images.

I've been trying to persuade various popular SDR software authors to include the option to add GPS derived co-ordinates to recorded signal strength logs in order to make this task easier, but no luck so far.

Good luck with your work.

Martin

Hi Martin,
I was not aware about your postings on this topic. Excuse me for that, you are ahead of me in technology. I read them with great interest. I will add them to the links in my article. Yes GPS sync is a need if a "noise" map? must be drawn but I have made these recordings just of curiosity to see? what is going on with the man made noise in my county. The most important result was that I compared? the minimal recorded noise with the noise at my house - so now I know "where I am" . The VDSL systems are very rarely used here.- most common are LAN cables and cable TV. The telephone lines do not exist here any more - everything is GSM.? I choose 3.5 MHz as a center frequency? because in semi-urban areas I have noticed that there the noise level has a peak (between 2 - 4 MHz) I do not have an explanation for that.? It will be interesting? for someone else to make similar recordings in order to compare the noise pollution.? We do not need? precise calibration - the level of the noise in quiet places is a good reference point. The merit of pollution will be? Nc/Nq?? where Nc is the current noise level? and? Nq is a quiet place noise level measured in the same date and time(approximately) . (or Nc-Nq in dBm). This can be done by car (or bicycle? : -)
Chavdar lz1aq

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On Tue, Jan 4, 2022 at 07:34 PM, чавдар левков wrote:

I was not aware about your postings on this topic. Excuse me for that, you are ahead of me in technology.

Hi Chavdar,

No need to apologise, my webpage regarding the system is quite well hidden, and I haven't done any further work on it for several years.

At the time I was trying to develop a low cost system around an RTL dongle that could be used to map VDSL noise by driving around the affected area. The intention was to encourage local radio clubs to have a system that could be borrowed by members, in order to locate VDSL hot spots, and then to be able to provide evidence to the UK telecoms regulator in order to try and get the problem resolved.?

However there wasn't as much interest as I'd hoped, and the available software wasn't that easy to use. So in the end the project got put on hold, and in the meantime a new set of other interference sources, such as Solar PV and Car chargers have become more problematic.

I'm still hopeful that one of the SDR software authors will at some stage add the ability to use GPS co-ordinates. But at the moment Winradio is the only company I know of who are offering software a price that is unfortunately still not quite affordable to the average hobby user.



Good luck with your experiments, and thanks for all of the really useful and detailed information on your website.

I have found your recent index of articles to be particularly helpful in finding items of interest.



Regards,

Martin