Weather Stations and Ham Radio Go Together.

And this is the issue with running a weather station at your house. The readings just aren't going to as accurate as those taken by professionals.

Why?

Well, first of all most people live on a relatively small lot, surrounded by other houses, often with trees and outbuildings. Depending on the placement of the station, this either puts it in a location where the wind is blocked, or where the wind speed is artificially high where it is forced to pass between houses. This is why you see a lot of TV news using airport AWOS or ASOS readings, because those stations tend to be placed out in the clear where wind effects are more consistent, and ground turbulence minimized. They need that feature to give aircraft accurate wind information for doing safe approaches. It also allows them to get consistent temperature readings, because the station isn't surrounded by islands of hot and cold, created by the maze of city streets and rooftops, and irregularly-distributed trees.

I have a remote thermometer near my back porch in the back yard. The morning sun heats up the slab under the porch and causes the temperature measured anywhere around the porch to be much higher than the real temperature. As the morning rolls on, the measured temperature comes down due to less heating of the slab, and eventually is within a few degrees of the AWOS station of the local airport. The thermometer is good for gaugeing when to work outdoors, and when to not. But it is nowhere near the level of accuracy needed to be meteorologically useful.

Having a weather station is definitely fun, and you can learn a lot by watching one. But when used in a residential setting the readings are far from accurate.

 

I’ve had my Davis Vantage Pro 2 ISS mounted right under my 2 meter antenna (~ 15’ from base of antenna) for 7 years now, on a 4x4 post, no issues. The anemometer is mounted higher on the same pipe as the antenna. It’s ~ 30’ from my Cushcraft R8 vertical. I LOVE this weather station, it has worked perfectly since the beginning. Check the readings out on my QRZ page (WB8ZTP). My email is good on QRZ if you have any other questions. I also upload to Weather Underground beside Davis.



73, Mark WB8ZTP

 

Eric, great job! I’ve had my Davis Vantage Pro 2 for 7 years now. I love this weather station, it has worked perfectly since the beginning. Check the readings out on my QRZ page (WB8ZTP). I also upload to Weather Underground beside Davis.



73, Mark WB8ZTP

 

To be honest, if anything does ever happen, those who stuck with staying ready are extra valuable, because so many will have washed out from boredom.

 

I've had the Davis VP2 for many years now also and in fact, one of these days I need to send it in for service after 5 or 6 years in the Arizona sun... I love this station and got this one after having a OS wireless due to the transmitter update intervals, Davis is much faster. Anyway, I as a few others have said, upload my data to CWOP and WU and enjoy having data that's been rated well for many years. That said, there are a couple of things to note with this station and one was mentioned in the video. First, the display has a very nice backlit display but as mentioned, if you leave the backlight on for an extended time, like 5 minutes or more, the indoor temp will start to clime. I questioned Davis on this and they know about it and don't seem to care. I'm guessing they don't want to re-design the power supply and or re-locate the indoor temp sensor to correct this issue so, just remember, if you like to have the backlight on, your indoor temp is going to be way off after awhile. It's a pet peeve of mine since it should be a pretty simple fix, but... Since I use the Dataloger and USB connection as other are too, I use the Weather link software that comes with the dataloger. It's pretty good stuff but even after all these years, you can only start the console at boot up of the PC but you can't get it to display the station current weather without selecting the Icon. The unit will still report data to CWOP and WU, but the display is just a blank gray screen. :-( There was an attempt to make an add on software program, (free for just this weather station and its software) that monitored the output of the Weatherlink and if it hung, (was an issue in the early years) it would re-boot the software and was supposed to have a hook in it to bring up the display, but I could never get it to work and I have not found any modifiers you can put in the command line for startup of the software to turn on the display. These are somewhat minor although look how many words it took me to say minor... Anyway, a great unit and I would buy it again in a heartbeat if I needed to. One last thing, I also live in an HOA area and they have never said anything about it. As a matter of fact, I offered to provide the data to the landscaper to let them know when to turn off watering systems in the community if we had rain in our area. I don't know if they use it, but they have the links to get it if they want. My wind speed and direction are up about 23 feet AGL and the main ISS is at about 6' AGL. I live about 5 miles from the nearest commercial airport and my data and theirs track to within 1 or 2 degrees for temps. Wind speed is the only data point that is different and in some cases the direction, due to local terrain, but that's about it. Finally, the last thing to note and was mentioned in the video, was the pressure sensor for barometric pressure. The sensor is located in the console as noted and it is quite common in home weather stations for a couple of reasons. First, out doors, it need to be sealed up pretty well to keep dust and other nasty things out of it just like the rain gauge buckets. Second, the pressure inside the house is the same as outside with one exception that can get lost in the mix. If you live in an area where you use swamp coolers, (Arizona is one of them, but I don't have one) and you understand how they work best, (piping in the cool air at one end of the house and only opening 1 or 2 windows at the other end, if you have a high enough fan speed and smaller opening/window, you can slightly pressurize your home. It's not a lot, but it can increase the pressure and give you a false reading??? That's not unique to Davis since any station with the pressure transduce inside would do the same.
All in all, the Davis AP2 is really a great station and I would highly recommend it for the money. You can get them traceable to the standards, but unless you really need that, I wouldn't bother, its pretty dang good out of the box! That's my $.02 worth and I hope it may help. Great video and as far as HF or interference goes, I have never had any issues with RF and the system. We have stucco homes that have chicken wire in the walls that make great Faraday cages, (assuming you want that in HAM radio... NOT! ) and my station has never had and issue with that either and it's about 75 feet between the units.
73

 

weather.janeandjohn.org

I've had my Davis Vantage Pro2 running for several years, I upload to CWOP and Weather Underground along with two Web cams. My sensors meet NOAA specs, temp and rain collector about five feet off the ground in the clear. The wind sensors are about 10 meters off the ground also in the clear.

The Vantage console interfaces with an embedded headless server running Linux and the weewx application.

 

The local news stations always have their temperature, wind and UV located next to a river or stream. My weather station is normally 10 degrees higher than the local weather mans forecast. And my wind speed is always less than reported.

 

I have my Davis Vantage Vue ISS and consoles about 50' away from my 2m/440 antenna, as well as my 6m and triband yagi (10/15/20m). Have never had any problems working up to 100 watts.

 

I have my Davis Vantage Vue ISS and consoles about 50' away from my 2m/440 antenna, as well as my 6m and triband yagi (10/15/20m). Have never had any problems working up to 100 watts. 73 KI7CKE

 

Nice video and nice forum. Enjoyed comparing notes.
I've had my WeatherMonitor II (WM2) since 1994, and only small problems occurred once installation was completed. The WM2 is a fully wired system, and I have all the options except soil moisture and sun intensity. It was a wedding gift. Okay, so she [we] got to go to Club Med Columbus Isle (check it out!) for her wedding gift.
The original system did not work because someone powered it up prior to connecting it up. The WM2 is NOT a hot-swappable unit. The previous owner apparently didn't know this issue. The warranty replacement worked perfectly first time powered up.
Sometimes when I run 1499 watts on 80m, the temperature will be measured at -101F. If you see that in the software, you can easily delete it in the database.
After 15 years or so, the wind speed sensor (cups with no-stop pot) seized. I used a drip of Pennzoil 10w30 on the bearings and it was back on line.
One issue I've wrestled with for years is the rain cup. Here in SC, the 110 foot pine trees drop their needles every winter, and ONE NEEDLE will stop the auto-dump function dead in its tracks. So, it will fill up with water. If it's not caused by pine needles, then small pine bark bits will clog the hole at bottom. I end-up cleaning the sensor about every 3-4 months as a result. It's not fun, because the only place I could mount it in the open is on the roof or in the middle of the front yard. Yeah, I've tried everything I can think of to keep it clean, but no joy.
When I clean the rain cup, I clean the outdoor humidity sensor, because in this hideously humid environment green mold tends to grow on/around it in the isothermal container.
NOW FOR THE GOOD STUFF:
The temp is always within 0.2 degrees of my calibrated Fluke thermocouple, and as such tracks with the NWS usually. Same with all the other readings except wind. The 110 foot pine trees keep that from happening.
I'm EXTREMELY satisfied with the hardware, especially when you consider the thing has been on constantly for nearly 25 years!
I record stat's every hour, so several official databases have been compared to mine for calibration and historical purposes.
Because I'm lazy when it comes to programming, I just did enough of a web page to get the info out there. The neighbors are ecstatic, because we live in a valley, and humidity or temp can vary slightly from the official. Rainfall can be slightly different because of isolated showers, but when it tracks with the official reading, it's usually within 1/8th of an inch.
The neighbors like it for telling them when their plants might freeze.
It updates to the web every 8-10 minutes.
The software is interesting; lots of predictions can be gleaned: dewpoint at 5pm under most circumstances is the low temp upcoming; the baro spikes upward (you know, the ole "hockey stick graph?") IMMEDIATELY upon rainfall commencement.
Bottom line: having one of these is a BLAST.
There are many other quality units out there, but the neighbors haven't had too much luck with the ones available locally at the super stores. They seem to fail in about a year, probably because the weather and thunderstorms here can get pretty nasty.
Check out my weather web page (software from manufacturer): http://home.earthlink.net/~creesesc/wxdata.html
A network of vastly more expensive weather gear to compare to is here: http://www.rcwinds.com/
I'm just NE of Columbia in Forest Acres so MLK and/or HQ (point to the orange flags) would be closest.
BUY ONE FOR CHRISTMAS!