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Author Topic: transmitter height  (Read 2767 times)

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Offline aardvark

  • Posts: 6,392
  • Des Moines, Iowa
  • Des Moines, Iowa, USA
    • Des Moines, Iowa Weather and Climate
transmitter height
« on: August 08, 2009, 01:55:07 AM »
I have found that with the VP2, reception the console seems to be dependent on how high (elevation) the various transmitters are.   I am running with  7 stations including the ISS and one would assume a drop in reception would be in order.  I average about 95%  over all and that isn't bad.   

I found that with my shed transmitter the reading was 87%.  So I went  back and lowered the transmitter so that it was about at the same level as where I thought the console was by the IP weatherlink.  It improved to 91%, so I think there is merit.  I also had my wireless anemometer above the ISS for that second anemometer and got terrible readings into the 80s,  so I put it on a spare mast and we are doing in the 97% range.. again  the height in relation to the console of the transmitter does seem to have a lot to do with the reception. 

Something to consider when working with reception
http://home.mchsi.com/~dsmweather/station_setup.htm
Davis VP2 Plus; 24h  FARS; Extra Temp Humid sensor (2); Extra Temp Station (2); Soil Moisture/Temp Station;Weatherlink IP;USB; MAC Mojave;https://www.weatherlink.com/embeddablePage/show/1c484adbfa914d1aa10a58ad53ccd563/summary

Offline looney2ns

  • Posts: 3,222
  • Fearless Weather Dog-Loves to watch Lightning.
  • Near Evansville Indiana USA
    • Newburgh Weather
Re: transmitter height
« Reply #1 on: August 08, 2009, 05:16:56 AM »
Your metal roof probably has something to do with that.

Offline aardvark

  • Posts: 6,392
  • Des Moines, Iowa
  • Des Moines, Iowa, USA
    • Des Moines, Iowa Weather and Climate
Re: transmitter height
« Reply #2 on: August 08, 2009, 03:38:32 PM »
when we had that long term roof put in and I really wondered about it.  When I had a vp1, for the same 100 foot distance , I was lucky to get 87% reception on the ISS alone. With the VP2  I am up in the upper 90s.  WHen the roof came on board, no difference in the reception rates at all.  Now, if I wanted a Boltek, that roof would have a definite issue.  It is interesting.. it is like shingle , but the stone is fused to the sheeting and  to look at it, it looks the same as asphalt shingles..

Davis VP2 Plus; 24h  FARS; Extra Temp Humid sensor (2); Extra Temp Station (2); Soil Moisture/Temp Station;Weatherlink IP;USB; MAC Mojave;https://www.weatherlink.com/embeddablePage/show/1c484adbfa914d1aa10a58ad53ccd563/summary

Offline N7XSQ

  • Posts: 465
  • Phoenix, Arizona
Re: transmitter height
« Reply #3 on: August 10, 2009, 01:25:15 AM »
It may be due to the angle between the antennas. They transmit and receive the best at 90 degrees to the axis of the antenna. They will receive almost nothing from you when the tip of the antenna is pointed right at you. In between the two angles it varies, with the exact pattern depending on the design of the antenna. Therefore, if the two antennas are pointing straight up, you will get the best transfer when they are at the same height because that places the each unit in the strongest lobe of the other's antenna pattern. They also will not receive well if they are at right angles to each other. For example when they are directly above each other, and both are oriented horizontally, but one is aligned East-West, and the other is aligned North-South.

Steve


Offline Stuart

  • Posts: 30
  • Fruita, Colorado, USA
    • Wet Rocks
Re: transmitter height
« Reply #4 on: August 10, 2009, 06:24:44 PM »
I would think the "line-of-sight", walls, trees,..  between the transmitter antenna and the receiver antenna would have the most effect. Having the two antennas in vertical alignment (tilt) should also have an effect the reception %. However, how close to 100% does the signel need to be for the system to operate in-spec?
Stuart DW0581

Offline aardvark

  • Posts: 6,392
  • Des Moines, Iowa
  • Des Moines, Iowa, USA
    • Des Moines, Iowa Weather and Climate
Re: transmitter height
« Reply #5 on: August 10, 2009, 06:48:23 PM »
moving the unit raised it to 93% reception over an 87.  and yes, line of sight plus everything else , rfi  and so forth   would have a direct effect on reception.
Davis VP2 Plus; 24h  FARS; Extra Temp Humid sensor (2); Extra Temp Station (2); Soil Moisture/Temp Station;Weatherlink IP;USB; MAC Mojave;https://www.weatherlink.com/embeddablePage/show/1c484adbfa914d1aa10a58ad53ccd563/summary

Offline Stuart

  • Posts: 30
  • Fruita, Colorado, USA
    • Wet Rocks
Re: transmitter height
« Reply #6 on: August 12, 2009, 07:09:12 PM »
"VP Live" is showing a 2-min average reception of 95% @ 1300hrs local time. My USB Envoy is at eye level here in this room, ground level. The ISS is higher at 8-feet on a 10-foot, 1-1/2-inch mast and about 50-feet away, the far side of the house. The anemometer is about 15-feet above the house roof (the roof is about 15-feet off the ground) so the anemometer is 30-feet above the ground with it's transmitter mounted at eye-level on the roof mast. All antennas are vertical. Pictures at 7...... :D
Stuart DW0581

Offline aardvark

  • Posts: 6,392
  • Des Moines, Iowa
  • Des Moines, Iowa, USA
    • Des Moines, Iowa Weather and Climate
Re: transmitter height
« Reply #7 on: August 12, 2009, 08:24:02 PM »
what I find is spooky..my envoy is in the basement, maybe 6 feet below the ground, which would be 11 feet below the line of sight and I am pulling at least 95-100% reception.

What I am guessing is that all the pipes, wires and assorted house crap is providing a channel to the Envoy... Just lucky.
Davis VP2 Plus; 24h  FARS; Extra Temp Humid sensor (2); Extra Temp Station (2); Soil Moisture/Temp Station;Weatherlink IP;USB; MAC Mojave;https://www.weatherlink.com/embeddablePage/show/1c484adbfa914d1aa10a58ad53ccd563/summary