What difference does space diversity make on BH30/60. I ran the link estimator along with path profile, and it did’t make much difference even in the reliability. A little bit more reliable than having no space diversity at all. Another thing I noticed in estimator was that if I wanted to keep diversity in and end which was higher than other end, the distance was more, like multiples of 5, whereas in lower end it was multiples of 0.72 or something like that.
What do you suggest, space diversity or not?
Any one please share their experience, running with and without space diversity
suggestions needed please
We run Polarization only, never tried spacial. I have heard that on really tuff paths spacial is better though. otherwise i don’t think it healps that much.
Mike,
Could you tell me how long are your shots and which antennas you have been using, how much of fade do you experience from your strongest signal, it would be pretty helpful
We use Andrew PX2F-52-NXA dishes, links are as follows:
17 Miles – Really tuff path but one end is a Water tower. 7.42Mbps each way, Max Fade of 7dB Max Fade, but was for a very short time.
Second 17 Mile hop – Really a pain to line up, blasts right next to another tower, running at 8.66Mbps. About 3dB of Max fade.
We really like the ortho geminis, spectras are a little picky with noise so we don’t use them anymore, but we pulled all the BH20’s out in favor of Geminis.
Thanks mike,
My links will be around 50-88 miles long. So I was wondering if space diversity is must in these sort of long links.
Well then… that’s a horse of a different color.
I would think that you would want to run space diversity for links that long.
Have you used the link estimator tool? You can get it from your supplier.
Jerry,
I have used that and when I put space diversity, I get little improvement in reliability, throughput is same. I was wondering if it was only little improvement or actually more
Might be a good call to have with a moto application engineer.
Those are some pretty long links…
The longest shot I have with 60’s is 79.7 miles. The link is running at 64QUAM 7/8 running at maximum recieve mode. Currently I get 14.86Mbps each way at about a -72. It did run around a -69 but with all the nasty weather lately something might have moved on me.
We have several long shots between 30 and 79.7 miles. None of them are space diversity, and all are using Gabrial 4ft duel polerized dishes.
The 79.7 mile link should have the 6ft units instead, then I might get a little more out of them.
Thanks Attitude,
What’s the lowest throughput do you get in the 79 mile link. What is the maximum fade you have experienced in that link? I have heard stories about links going down because of fade (thermal/ducting) in long distance.
Have you experienced any these?
Both end’s of the link are on mountain top’s co-located with large communications sites. I have all of them set to fixed freq. The only time i have any problem is at one end I believe someone else has equipment that shifts freq and will land on mine reducing threwput. I have 3 other units at that site all set to fixed so its not me. I never lose the link it just drops the threwput and the lowest it has gone is 1.5Mbps. Other then that one issue I have had no complaints with any of the links and i have 7 or 8. again 6ft dishes on that link might solve that problem. I experiance no fade issues on any of the links. just tune them real good. the temperature varies from below freezing to around 90 to 110 in the summer.