PTP 400

Dear All,

recently we bought 30mbps 5.8ghz bh (v&h antenna output), we use 30dbi semi grid antenna to work with (hyperlink)

The link is +/- 80km(50 mile), the tower height according to gps+antenna height is 127m and 82m. We look at the earth map, and found it is 100% LOS. According to link estimator:
1. los
2. the fresnel line(pink line) almost merge with the ground (brown line)
3. the new fresnel (blue line) intersect with ground (brown line)

What I can summerize is, the tower height is not enough because the fresnel zone is nearly merged with ground.

any ideas?

thx

Bigger antennas? The link uses in 30 mbps modulation 64QAM. It can be a problem if you upgrade it ti 60 mbps in the future to use 128QAM.

we are using 2 x 2 x 6ft’ers on a 60 mile link over water… rock solid…
on lite at the moment…

may need to go to spectra one day… the bigger the antenna the better…

any recommended “standard” antenna, since here in the 3rd world country, there’s no such maxrad, mti, radiowaves stuff…
(but yes, we use full set of maxrad antenna with connectorized ap ) 8)

VJ,

"we are using 2 x 2 x 6ft’ers on a 60 mile link over water… rock solid…
on lite at the moment… "

Are you using two 6-foot antennas on each side of your 60 mile link?

shouldn’t diversity be at one end of the link only?

what do you mean by "shouldn’t diversity be at one end of the link only? " :?:

one end should have a dual polarized dish and the other end should have two single polarized dishes, thats what I meant to say by having diversity at one end only.

I think you mean split diversity then.

That’s an interesting idea, and should work well over water. To have two seperate dishes, one on horizontal and one on vertical, on one side of the link and the other in a dual polarity antenna.

VJ,

what kind of antenna you use?
is it 2 set of parabolic antenna on both side, or
1 set of parabolic and on the other side is antenna with dual polirized?
(like nepalken said?)