30mile link with 20meg BH problems

we are having trouble with a 30 mile link that is mostly up and running. At times the RSSI is up above 1000 and jitter bouncing around 1 and 2. Then over a period of an hour or more the stats degrade and finally it will go down for 8 hours. During this time the units constantly slip between registered and then scanning. Here are is my setup.

freq 5735 (no other BHs in the area until 5760)
the Z end of this link has no other 5.7 freqs
the A end has links going in completely different directions on 5760,5785,5810,and 5835

We have tried moving things around from 5600 - 5850 (factory freqs) and have found that when we are int he 5710 to 5720 range we have the most stable connection. When we go to the lower Freqs we end up with lower jitter BUT lower Jitter as well. When we went up in Freqs we had better RSSI but Jitter was all over the place.

on the Z end we have a Command Module with GPS sync.

Please ask any questions you have. I really need this link to become stable soon.

I assume that the BH and the A end BH are all on the same timing? If not that can cause problems.

If you are timed, then it is likely you simply need more margin. The noise floor is too close to your operating level. The only solution there is to use a bigger dish on one or both ends.

We were trying to find other reflector options. Please let me know where I can locate other dish options. Thanks a ton.

I have heard of people using commercial satellite dishes and fabricating a mount for the radio to replace the LNB

http://www.lastmilegear.com/catalog/def ... p?cPath=75

We use there 4' dish and 2' dish on our 20 mile link works good there are 3 times a year it just quits working at night for a little while

Can you put me in touch with someone that has sone this? OR can you sugest a place to purchase such a dish to modify?

again
Thanks!

rollerd wrote:
We were trying to find other reflector options. Please let me know where I can locate other dish options. Thanks a ton.


do you use radio mobile? i would look at it to see where your fresnel zone is. also how high are your towers?
Buck0 wrote:
[quote="rollerd":l142lnew]We were trying to find other reflector options. Please let me know where I can locate other dish options. Thanks a ton.


do you use radio mobile? i would look at it to see where your fresnel zone is. also how high are your towers?[/quote:l142lnew]

I am over 180ft on one end and 200' on the other end with a 100' bowl in between the two cities.

I an not using radio mobil and have not RTM yet on what that settig will do for me. I just started a WISP in Wisconsin after becomming a late bluming dotcom refugee. This is the first link I've done over 20 miles and am relying on the knoledge of some of the first Canopy equipment that we bought at my old job before it went under.

Just do a Google search for Commercial DirecTV Satellite dish - you should get some hits.

what time of the day/night does this happen… is there a related weather pattern like always on a hot day ?

how often does it happen…


A LONG SHOT:

it is possible (in theory) that due to trapped air, you get different pressure/temperature bands… as the waves travel through one band to the next they will bend, with the eventual effect that what started off as an aligned link now becomes un-aligned and once the temperature level out the link is fine again…

This link goes down for hours at a time and i see it drop off in the early morning 4 to 6am but it comes back up at random intervals. One day it will be for 3 hours and another day it will be until 9pm. there are days that the link is up and I have minimal packet loss. I believe that we are going to use a different dish and see if that will solve the problem. I will let everyone in on the results later this week.

Thanks for your help



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vj wrote:
what time of the day/night does this happen… is there a related weather pattern like always on a hot day ?

how often does it happen…


A LONG SHOT:

it is possible (in theory) that due to trapped air, you get different pressure/temperature bands… as the waves travel through one band to the next they will bend, with the eventual effect that what started off as an aligned link now becomes un-aligned and once the temperature level out the link is fine again…

Can anyone please tell me about the ups and downs of an amplifier for this issue?

Can’t be done as the radio and antenna are an integral unit. The reflector is a passive amplifer and increasing size is the only way to get more gain.


Have you used the spectrum analyzer to determine what the noise floor looks like on this link? If not, you really need to. You might be trying to use a frequency that has a high noise floor.

It may be a simple as changing frequencies.

I will be conectorized on one end of my link soon. Do I have to use a radiowave antenna on both ends?

Ideally, yes.

If you use differing reflectors, you do have to be certain that both ends are polarized the same.

I do not know of Canopy compatible amplifiers.

We used a 4’ radio wave dish on one end and a moto 27" dish on the other for a long time. We did replace the Moto dish after about a year with the 2’ radio wave this is a nice dish mounts great easy to tune. didn’t see any improvement in signal. but it gives you the option to run two different backhauls on the same dish, verticail or horizonal. We now have our 5.8 backhaul along with 2.4 as a backup

Jerry Richardson wrote:
Can't be done as the radio and antenna are an integral unit. The reflector is a passive amplifer and increasing size is the only way to get more gain.


Have you used the spectrum analyzer to determine what the noise floor looks like on this link? If not, you really need to. You might be trying to use a frequency that has a high noise floor.

It may be a simple as changing frequencies.


We have used the spectrum analyzer and have moved to an open freq. We have even tried moving down into the factory Freqs. It was worse when we wne into 5600 and low 5700 freqs.
clueless wrote:
We used a 4' radio wave dish on one end and a moto 27" dish on the other for a long time. We did replace the Moto dish after about a year with the 2' radio wave this is a nice dish mounts great easy to tune. didn't see any improvement in signal. but it gives you the option to run two different backhauls on the same dish, verticail or horizonal. We now have our 5.8 backhaul along with 2.4 as a backup



We put the 3'dish on the end of the link with the highest noise floor and had it up and running perfectly for 2hours. With no warning the link dropped and now we can not get an RSSI that is half of what we had when it was up. We have been through multiple aiming attempts and I'm getting really good and climbing but I'd like to hear what others can suggest as a reason. I don't want to climb again until I understand what is going on. Please help me trouble shoot this.

We originally had two canopy reflectors and the link would randomly drop out and that is why we added the dish to the link and now are having more trouble than before.

what is your rssi and pwr level when working?

It is hard to say why it is not working 30miles is a great distance. this is what I would do, you may have already done this.

1. use the spectrum analyzer on both ends look for two clean channels.

2. on both ends use the Ap aval, and alignment tool to see who else is in the area.

3. Put the master on the cleanest channel and tune the slave to that freq, It does seem to make a difference.

4.Leave all freq’s checked in the slave, test unit

if its doesn’t work.

1. Larger dish on one or both ends
2. Find a hop half way and say yours self a lot of trouble.

is the Master timed with AP’s? Is it getting the sync consistently?

Jerry