Thread: antenna hight
View Single Post
  #10   Report Post  
Old February 10th 07, 10:38 PM posted to rec.radio.amateur.antenna
[email protected] znaqwi@googlemail.com is offline
external usenet poster
 
First recorded activity by RadioBanter: Feb 2007
Posts: 4
Default antenna hight

On 7 Feb, 15:43, "Richard Fry" wrote:
wrote The total distance between the transmitting and receivingantennaof a
microwave link at 10GHz, is 30 Km. the height of the Txantennais
above ground level is 20 m. the maximum acceptable total path loss is
169 dB. Furthermore there is hill located 10 km away from the
transmitterantennawith a height of 80m.


calculate the height of the receiverantennafor the path loss to be
just equal to the maximum acceptable value?


_____________

The height above mean sea level of the tx and rx sites, and the terrain
profile for the path would be necessary to answer this ~ accurately. But
for a smooth earth model, the graphic at the link below will give some
insight.

It shows that a height of around 270 meters would be needed for the receiveantenna, using a K-factor of 1.33 and 0.6 fresnel clearance for an 80 m hill
10 km downrange. The path loss then would be about 142 dB.

http://i62.photobucket.com/albums/h8.../10GigPath.gif

RF


hi

Richard
i have read ur response very carefully and its perfect 142dB Path
loss but problem is that what's the Rx height
if i suppose Tx and Rx install on the same height
then my Rx height after the earth buldge and knife e calculation
i have got 100m Rx
its totally wrong
because
if i increase that (100m) Rx height its mean get the problem at
fresnel Zone

need help

thanks
regard

naqvi