HFU HF Underground
Technical Topics => Equipment => Topic started by: Ray Lalleu on July 27, 2023, 1957 UTC
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I know it's not this thread, but it's important for the oppressed SWLs !!!
- after sunset, the panels do not work, but the photovoltaic installation can give energy to the home network from the batteries via "inverters", which still generates RFI for some time! >:(
When the central inverter gets energy from the batteries, it should send nothing to the panels. But if you are close to that house, the RFI can jump to the overhead power lines.
How wide is the RFI ? Here, it's between 4 and 8 MHz, with a maximum between 5 and 7 MHz.
All other frequencies are jammed near the offending house, but only the lower SW bands have an efficient antenna : all the wiring above the roof.
(I will move this to the proper forum)
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You're right Ray! It was a short period after sunset - the neighbor had an air conditioner powered by photovoltaics. Even during the daytime hours of operation of the panels, the antenna of the small HRD-747 receiver did not detect interference in direct proximity to the panels and their cables. Interference is generated by the Inverter, located about 25m from my antenna line. My range of interference is similar to yours - the strongest are from 5 to 7 MHz and reach about 11 MHz. Maxima interference saws are every 20kHz, which I showed on the screenshots in the topic Software - Console V.3.3
Jul 28 2023 (http://Jul 28 2023) And this is what 16MHz spectrum looks like today at noon!
(https://i.imgur.com/fhXbnW1.jpg)
If I lived here permanently, I would have to drink a lot of vodka with my neighbor and spend several hundred euros on ferrite cores to secure his installation.
Fortunately, its installation is not electrically connected to the public power grid.