Inversion Layer question?

[mohave_steve]

I have been troubleshooting an issue with a 4.9 PTP link and am begining to wonder if the issue could be weather instead of a hardware issue.

The hardware (unfortunately) is not Ubiquiti.

Details:

Three individual links: 5miles, 17miles & 22miles each link running (up to) 400mw & 23db antenna. The two longer links transit from mountain to to mountain top the shorter link shoots down into the valley to our gateway. The link at issue is the shorter 5mile link.

Initially we had ocasional loss of radio link between the two points. When it was running signal strength & throughput were very good. When it would fail linnk would drop & it required cycleing power at the far end to bring the link back up. This issue bacame more & more frequent until it was occuring minutes apart. We wound up replacing radios at both ends.
Both radios removed from service werre tested later at the shop and failed there as well.

The new equipment ran perfectly for 35 days and early in the morning on the 36th day the link failed. Keep in mind that we have three PTP links that are located at the same point. The failure occured at about 5:00am. The symptoms of the failure werre simply lost rf link. Zero signal showing. Resolution required cycling power at the head end. The link ran fine for another week then failed again. Same symptoms & time of day.

The only common condition I can find is that we have only had two mornings so far that the temprature has dropped to 20F. Could the fact that temprature tropped that low and the link we are having trouble with sees a 1400' elevation change point to weather issues and not hardware failure??

[WHT]

I don't think you'll have that much of a temperature inversion before the sun rises. Did you have a sudden cold front or warm front, or high or low pressure front move through your area at the time?

Check your PM and send me your GPS numbers.

[mohave_steve]

I am not certain what the front activity at the time was. I was not looking at weather related causes at the time of failure. It was well after the fact that I realized the two failures coresponded with particularly cold mornings.

[jp498]

I have seen similar things on a 52km link we have at 5.8ghz. It typically happens real early morning when the air is very still. It functions normally when the day begins and the sun gets temperatures changing and air stirring. One end is at about 600' on a hill, the other is at about 280' feet on a tower on a 100' hill.

[WHT]

Steve...

Looking at your terrain, its going to be hard to imagine you having a temperature inversion. Although you could get that on your Starbuck to Turner link.

[mohave_steve]

WHT,

What terrain feature are you refering to? I am not knowlegable regarding conditions causing an inversion layer. I do know that they are common here in cold weather. At times you can see the smoke from woodstoves rising a few hundred feet and stopping.

I may have more info on the issue as our low temp is supposed to be around 3F tomorow and we will be seeing continuing cold. No warm fronts trapping cold air at the surface though. Perhaps this will tell me if this is simply a temprature problem?

[mohave_steve]

JP498,

The elevation change on this link is over 1500 feet. The mornings we have seen the failure the weather has been very still and 20F or colder.

[WHT]

At times you can see the smoke from woodstoves rising a few hundred feet and stopping.

YUP...that's an temperature inversion layer. Ok, disregard what I said about not seeing how you would have inversion layer problems.

[mohave_steve]

Well I have come to the conclusion that the trouble is not due to an inversion layer.

Sunday morning temps dropped into the teens and the link went down.
Temps have been ranging from 4F to 18F since and I cant keep the link up. No inversion layer conditions. Just freaking COLD!!

Oops!! Just looked and temp has dropped to 3F..... Anyone want to climb 140' tower for me today? -11F wind chill....

Thanks for the input guys.

[Wolfie001]

I'm wondering if i need to worry i'm going to be running 2.4 but my highest link is at 5300 Ft and it will be connecting to a link at about 700 Ft with a 16 mile range... any thoughts or sugestions?
the temp normaly changes by 5-20 deg as you are going from point a to point b.

[mohave_steve]

Update:

I have installed a power controller that pings the far end of the link and cycles power if it does not receive a response for one minute.

The connection is good when temps are 20F or higher, flakey @ 10F-19F and unusable below 10F.

Hardware problem. Will be replacing the Solektec gear with (hopefully) UBNT.

Rant:
We had purchased 8 Solektec radios. They have been in service 3-12 months and 3 have failed so far. Solektec was kind enough to exchange the first two for refurbed radios at a cost of $800 each. The last one is a lost cause. No help from Solektec.

PTP link radios @ $2300 each. 38% failure rate in first 12 months.....

Anyone want to buy some hardly use Solektec radios???

[Wolfie001]

ohh man, i think I'd be a little Past the upset side, i did the math on that, that's ALOT for the short amount of use. i have read the specs on the stuff here, and I'm wondering if I'm going to need to pack my stuff in a box with some heat tape. (it was -17F the other week) but i have faith that the guys here aren't just out to slap some semi working crap together and put it on the market.

[WHT]

Steve....

Guess how many Google search hits you get for Solektec failure rate? ZERO..."Your search - Solektec failure rate - did not match any documents. "

That means if you post a few things in different forums with the phrase Solektec failure rate, word will get out of your experiences. Wait a few months and see how many follow up posts you see to your various comments.

THEN call Solektec back.