Static rain.Static rain can easily rise above S9 on 144 MHz. I have no experience with other bands, but from theory I would expect the problem to be present on most amateur bands, maybe with an exception for low bands where the atmospheric noise might be very high.Different antennas have significantly different response to this kind of interference. A Beverage that is a couple of cm below ground is probably not sensitive while a horizontally polarized yagi antenna would suffer badly when hit by charged raindrops. More data on this kind of interference is urgently needed. I believe it can be totally eliminated with adequate hardware and good SDR algorithms. Look at the info currently at hand static rain screen dumps. With more and better info it will be possible to demonstrate how static rain can be eliminated under difficult circumstances with strong signals present. The optimum procedure on a band where only very weak signals were present would be a wideband amplitude limiter with a bandwidth of 10 MHz or so. Broadband over Power Line.It seems like different modulation schemes are used by different companies. Some use OFDM and they are hard to eliminate in SDR. If would probably be necessare to decode the message to be able to build the proper signal to subtract.It seems however that other companies use some kind of UWB scheme with the information coded in pulses. It is possible that such interference can be eliminated, but more info is needed. This link:Power Line Telecommunications Shows some data but more importantly tells what is missing. To SM 5 BSZ Main Page |