| Author |
Message |
    
Barracuda
| | Posted on Tuesday, December 09, 2003 - 11:10 am: | 
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In all my reading on antennas and propagation recently I believe that the "better" (more conductive) the ground the lower the angle of radiation. First did I get that right? Second, It seemed to me this past Sunday that the ability of my mobile to DX on the net was better than ever before. Now, since I installed the radio in the car earlier this year, we've had all kinds of atmospheric conditions that affected my signals propagation and therby my ability to be heard. From the mobile I've never been able to get more than about half way across our country. On Sunday, I was heard by at least 2 Califormia stations (looking at the logs posted). Nothing changed in the truck, so it left me scratching my head as to why. What I came up with is a combination of atmospheric AND ground conditions. I am guessing that the blanket of snow somehow enhanced my radiation pattern and helped. Does this make sense?
Barracuda |
Bruce
| | Posted on Wednesday, December 10, 2003 - 5:00 am: |
|
it does effect things i dont know if the modeling programs can be set up to show it. |
Tech833
| | Posted on Friday, December 12, 2003 - 11:13 pm: |
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Yes Bruce.
Barr- Yes. Not much, but a little. |
Mr_Rf
| | Posted on Saturday, December 13, 2003 - 1:05 am: |
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In general, snow has very minunal effect on ground reflections at 27 MHz.
Specifically, any form of water has a resonance near 900 to 1100MHz with increased reflectivity as you approach 10 GHz and higher where it begins to have RF properties similar to aroura by causing doppler shift in the signal and by 100GHz the doppler shift nearly renders the signal useless. |
Tech833
| | Posted on Saturday, December 13, 2003 - 4:22 pm: |
|
Doppler shift in snow is almost unmeasureable. Actually, 'doppler' is not appropriate, 'velocity factor' would be more accurate. |
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