See rich T's list of frequencies. As I understand it, the Davis transmitter sends each burst at one of those, and then moves to the next for the next burst. The point is to move around so that any interference that is localized in frequency will not interfere with many transmission in a row.
Given this slow hopping, there are multiple: interesting points for your situation: *) Since you have extended periods at zero loss, probably whatever is causing trouble is relatively broad, affecting the entire 902-928 band. *) There are several freqencies near 915, so if you are listening to 915 +/- 1 MHz, some transmission should show up. At 2.5s interval (from dim memory, and I amy well be off), and 51 frequencies, that's 127.5s. So a waterfall around 915 should be useful. So, I'd be inclined to run in waterfall mode and adjust gain so that the background noise is considered relatively not so high. One tricky part is that rtl-sdr is often run in automatic gain control mode, so you don't really see more total energy on receive, but shifting from broadband to hotspots and quieter areas. In your plot, the strong line at the tuned frequency is I believe a normal artifact and not concerning. There is some structure in what I'm seeing, but nothing super strong. I do not know how long the Davis bursts last. There are a few things that could be that, if they are short. I would suggest that you 1) look at the waterfall for a full 127.5 seconds, so see if you see any vertical streaks and 2) keep it running, and maybe set up an alarm on low receive% from davis, and then look, and see if it looks different that how it looks when things are ok. -- You received this message because you are subscribed to the Google Groups "weewx-user" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/weewx-user/rmiwo8i14q4.fsf%40s1.lexort.com.
