Thanks, Greg. Nice to hear from an expert! On Tue, Feb 11, 2020 at 9:47 AM Greg Troxel <[email protected]> wrote:
> Troy Lass <[email protected]> writes: > > > Over the years I seem to get signal quality at 0, often. I'm not moving > > the console, in fact I get the same thing on a console and a envoy in > the > > same location. > > > > The console is approximately 25 feet from the station and I can see the > > station in a clear line of sight from the console. > > So 25 feet line of sight means that the path loss (difference between > power into the tx antenna and power coming out of the rx antenna, more > or less) is almost certainly not an issue. I mean that if the > transmitter is working, and there is no strong interfering signal, then > this should be solid. > > I have a VP2 with the console about that distance away, but with maybe 2 > walls in between. I see spikes from 100% down to maybe 99% mostly and > 96% once over a month, maybe twice over a year. > > Given that two base stations are seeing the same problems, there are > three hypotheses: > > A) The transmitter is failing to transmit correctly > > B) There is some interfering signal > > C) Both receivers are defective in a similar way > > D) Something else we don't understand (always there, but good to list) > > In my experience, when a Davis ISS has transmitting issues due to power, > it will stop when it's cold, or dark, and then start again when it warms > up or gets sun. Your pattern doesn't fit that. So this doesn't smell > like A to be. > > C seems very unlikely. > > For B, this does not strike me as a bizarre situation. There is a > tremendous amount of badly-designed and badly-built electronics that > radiates energy where it should not. > > I have a friend who had signal dropouts with an Acurite station in one > location, not closely matching yours, but similar in that they were > occasional and inexplicable. After the entired station was moved (well > over 10 km, to an essentially uncorrelated 433 MHz environment), there > were no dropouts. So I don't find your situation surprising. > > The Davis signal (assuming VP2) hops in frequency, to avoid narrowband > interference. I am unclear on the VP(1) signal. So it looks like, if > interference, that it's fairly broad band. In the US, this is in the > 915 Mhz range. This link may be useful, and there may be a maintained > version somewhere: > > https://github.com/bemasher/rtldavis > > This is also interesting: > > > https://madscientistlabs.blogspot.com/2010/12/davis-weather-station-hacking.html > > https://madscientistlabs.blogspot.com/2014/02/build-your-own-davis-weather-station_17.html > > Overall, I suggest that you get an RTL-SDR dongle and use gqrx to look > at what's going on in the radio spectrum. You should be able to see the > transmit pulses, and I believe that broadband interference will appear > very differently from weak transmit pulses. I would recommend that > you get a dongle with a metal case, an SMA connector, and a TCXO. > > I've used ones like: > https://www.nooelec.com/store/sdr/sdr-receivers.html?sdr_usb_ic=34 > to receive 433 MHz signals from eg. acurite sensors, but have not tried > to listen to Davis. > > Another thing to try is to unplug everything in your house that you can > deal with being unplugged overnight and see if that helps. You may have > a defective switched-mode power supply wall wart or semothing. > > -- > 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/rmi8sl9yq0z.fsf%40s1.lexort.com > . > -- 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/CAPq0zECcZEWehf3mbFjgjE-UAsNj%3Dw6bQtnKtqdU2h0xxAHpHA%40mail.gmail.com.
