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tilt
Premium
join:2003-04-11
USA
1 edit | Twas the night before christmas and my antennas were wet : (
Our temps have been hovering right around 30F for the last month or so. At night it may get down to 20, and in the day has been hitting 40 pretty consistently. Very uncommon weather for Minnesota. It's usually MUCH colder in January, with highs of maybe 20. We don't even have any snow this year.
I'll describe here, a nasty story of how it took me 3 or 4 climbs to figure out what was wrong with one of my AP's. I suspect I may have some moisture problems in my antennas due to all this freezing/thawing/rain we've had, as I've used the same model throughout my network, and made the same mistake when installing them all. This week I'm going through as many as I can, replacing/repairing them and the cables.
- Friday morning, Dec 22nd, SE Minnesota.
One of my mesh nodes disappears. Stops checking in every half hour like it's supoposed to. I get a couple calls from customers without internet. I drive out, and reset the power on it, which has worked many times with this particular AP. It still won't get a connection. This is a repeater node, and has no backhaul connection. It gets dark before I decide to replace the radio.
- Saturday morning, Dec 23rd.
I go up the silo this AP is mounted on and bring the entire assembly down to the ground, take it back to the lab and replace the entire WRAP board/radio and amplifier. Test it on the ground, it works. It meshes with another node 2 blocks away, it is fixed. I go put it back up. It won't mesh with neighboring nodes. I take it back down. This time when laying it down to think about what to replace next, I see water dripping out of the tube the antenna mounts in.
The antennas I've used on all my AP installations is the Comet GP-24-3. It's a 15dbi omni, with 3 degree electrical downtilt. These antennas come with an aluminum tube, which you clamp to whatever vertical mast you're mounting on, then the antenna itself slides down into that tube, and is held in place with a single set screw, keeping it from jumping out the top of the tube and tipping over. Your cable attaches at the base, and sits down inside the tube keeping it protected from the weather.
When I first started using these antennas, over 2 years ago, I noticed the 10" long aluminum tube the antenna sits in is rather sharp where the RF cable exits at the bottom. My solution to protect the cable, was to stuff some plastic packing foam (the molded kind, not the flaky kind) into the bottom of the tube, surrounding the cable, so the cable wouldn't flop around and get cut by this sharp edge.
Well when I pulled this foam out of the bottom of the mounting tube, about 2 cups of water came rushing out. NOT GOOD. The N connector had been sitting under water. Apparently I stuffed the foam in the tube so tightly it held water, and over time, moisture had penetrated the top somehow, filling the tube.
So huh, get out the blowdryer. I dried the antenna connector, and also grabbed a new 3' LMR400 jumper. I've heard that white layer in the cable can get saturated with water too. Put some dialectric grease around the lip of the male connector. Put everything back together and it tested pretty good, and I figured it should only get better if things dry out more.
I put it back on the silo.
Still wouldn't talk to any other nodes. GRRRRR
Take it back down. Now it's too dark to try anything else. Sleep on it.
- Sunday, Dec 24th. (Christmas Eve)
I go to take a look at the assembly laying in the floor, and huh, there's a puddle of water under the connector I just dried out. I KNOW THERE WASN'T ANY WATER LEFT IN THE MOUNTING TUBE. Where was it coming from? Hmmm... The antenna?
Disconnected the cable. Took a set screw out of the base of the antenna to pull the element out, and a cup of water runs out of the antenna itself. I thought, "How could any water possibly get into the antenna?" It's sealed perfectly top and bottom.
I concluded that when I laid the whole assembly on the floor the first time I went to work on it 2 days earlier, the horizontal position allowed the water trapped in that base mounting tube to funnel up, into the antenna mast itself. Since then, I've read about how condensation can actually fill an antenna mast if it is sealed at the bottom so it can't drain out. I'm hoping real bad it was just the fact that I laid it down horizontal.
From now on, I'll be caulking where the antenna meets the mounting tube on this model, and around the set screw. I will also NOT be sealing the bottom of the mounting tube with foam. I'll be deburring the sharp edge of the aluminum tube, and wrapping some tape around the LMR400 cable where it exits the tube.
This antenna was recommended by several vendors over the cheaper models that look homemade using pvc tubing. They really do look well engineered, although the way they mount to that tube at the bottom really is a flaw in my opinion. Being they only use a single set screw, it allows for play where the antenna meets the tube, making it virtually impossible to seal out moisture.
Do any of you have any more information on condensation building up inside an omni mast? Is this common?
Attached is an illustration of how this particular antenna looks. It will give you a better picture of the mistake I made, and the place I didn't think to caulk.
Hopefully any of you using this model omni antenna can learn something from my nightmare here. If you have any ideas on a better way to protect this model, let me know! | |
joshg409
join:2005-05-03
Ottumwa, IA
| Oh yea, I forgot to tell you to not fill the bottom hole of the mounting sleeve for your omni with sealant!
We found this awhile back when we moved an omni higher on the tower. For some reason we lowered it to the ground and I noticed a puddle developing aourn the base. We thought that it was best to seal the end so you know bugs, water and things did not get in there and tear things up. Well I removed the coax seal plug we made to seal the hole. Also we thought the hole needed to be sealed to prevent chaffing of the antenna cable in the wind against the aluminum tube. Anyway the tube had probably 3oz. of water inside. We however didn't have problems because the n connector was coax sealed before it went through the tube. Luckily for us we didn't have any issues. | |
Bigpaddy_Irl
join:2005-12-12
Ireland | By any chance do you use LW for your operating system? You said they check in every 30 mins or so which tells me your talking about Wiana? | |
tilt
Premium
join:2003-04-11
USA | Yep, is LocustWorld Mesh Paddy. | |
Bigpaddy_Irl
join:2005-12-12
Ireland | What do you think of it? Any problems? | |
tilt
Premium
join:2003-04-11
USA
| You know, I am still using the free version of the firmware. I have been for 2 years now. I hesitate to upgrade to the Pro firmware for several reasons. The main reason is probably because every time I come across a chunk of cash that could pay for the Pro version, I have other more pressing bills. The other reasons I don't upgrade are that yes, I have seen one technical problem after the other. Most of these technical problems were caused by misconfiguration on my part, but the documentation for the firmware leaves me guessing pretty often. There's a wiki that details each section of settings you can make, but it lacks detail. It's more like a "best practices" description, but it doesn't explain enough why certain settings need to be the set a certain way, and how they relate to other settings. When I first started using Locustworld mesh, I was told that I could deploy single radio nodes, and that they would mesh with themselves, finding their most efficient path back to a gateway. I find this is rarely true, and the mesh nodes will often choose the wrong neighbor to route through. I've since installed a 5.8ghz backhaul into the heart of my mesh, and lock repeater nodes to which gateway I want them to route though. I've also just added more than one gateway node at a main gateway location, allowing me to branch off of that location on different channels. I have found running repeater nodes more than 2 hops from a gateway is unuseable. Therefore my network now uses more of a star topology, rather than true mesh, and it's been more stable that way.
When I first deployed most of my network, there were no 400mw cards available. I've found that a single 200mw card with a 15dbi omni on it, is not able to communicate reliably over 3-4 miles. I ended up putting amplifiers on most of mine, which seemed to work, although Locustworld recommends against amplifiers. Partly I think because of the signal testing that goes on in firmware. Richard Lander always says to set your radio cards to "auto", and this just doesn't work when an amplifier is run between the card and the antenna. The firmware freaks out and thinks the signal is plenty good so it can turn the power down on the card, or it can actually turn the power up on the card to the point where it overdrives the amplifier. Depending on the cable length, I need to set the card output to a constant 30mw or 50mw running into the amplifier.
Basically I have been waiting to see some stability in my mesh before purchasing the Pro firmware. I haven't seen that it "just works" like it does for everyone else according to Richard Lander at LocustWorld. Now, I'm thinking that without the Pro version, I may never get the remaining issues solved in my network, because the Pro version looks like it includes better logging, and also has provisions for managing P2P traffic, which could also be crippling my mesh. So it would help troubleshoot anyway. Richard has let me try the Pro firmware twice in the last 2 years. The first was over a year ago, and when installed remotely to live nodes in the field, my network freaked out, performing WAY worse than it was when running the free version. It required a couple climbs to go replace nodes that stopped functioning, but once the free version was back in place, it worked as it did before. The second time I tried the Pro version, was 8 nodes set up on the workbench here, about a foot apart from each other, and I ended up needing those nodes to replace some live nodes in the field, and never actually got the Pro version deployed.
After discovering the moisture issue with these omni antennas I've been using, it gives me hope that once fixed, maybe a big part of the performance issues I've seen on my network in the last 2 years may be solved. Maybe the moisture issue has been plaguing my network, and the firmware was not to blame.
If I can see some improvement in things after getting the moisture problem solved, I will probably be looking at the Pro version again asap. The automatic throttling of P2P users in the newer firmware looks like it could solve some other issues I'm seeing as I add more subs.
There's another thread going in here concerning why someone would pay $1500 for a piece of big name hardware, when you can build something like Locustworld Mesh, or Mikrotik for $200. I can attest the the fact that That big brand name hardware is probably more hearty, and will withstand weather extremes like I see here, better than a homemade solution. I often wonder if I would spend less time running around putting out fires if I had just got a big loan and went with expensive gear. I honestly feel I did as much research as a could, and put things together correctly when i first got into this. There is just such a lack of support for LocustWorld Mesh, that I feel could be fixed so easily, that it's frustrating. I've mentioned to Richard more than once, that if there were a message forum focused on LocustWorld Mesh, I wouldn't have to bother him with my issues. We should be able to have a place to discuss issues with LocustWorld Mesh among ourselves, the users. I even asked Richard if he'd mind if I hosted it, but he didn;t sound very positive about it.
In closing on this topic, I must say that Richard Lander has spent several hours trying to help me get my network stable, and I appreciate that. The problem is Richard seems to be more of a sales guy than tech support. He knows plenty about how the system works, but where is Jon Anderson? He is apparently the guy who put all these open source packages together to create what we know as LocustWorld Mesh. I swear, I cannot be the only user who comes across the issues I do, and maybe if there was a users message board to discuss this stuff, Richard could answer a question once, and everyone else would read it, instead of Richard feeling like everyone wants his time for nothing. LocustWorld WILL be paid for what they've done for me, WHEN IT WORKS AS DESCRIBED. Who knows, maybe I am the only one in the world who has issues with it once in awhile.
So that's how it's been for me Paddy. | |
Bigpaddy_Irl
join:2005-12-12
Ireland
| Hmm....Sounds just like my story all over too. I too had great problems with the configurations in wiana at the start. To be honest it was all mostly my fault, wrong settings & not enough wi-fi education. This is my second year in the business now, second year using Locustworld Pro. At one stage I would never sleep at night, I would be going around in the car with the laptop at night trying to see what the problems were, trying to reboot nodes, etc. I often found myself at 3am in the morning climbing roofs trying to repair equipment. I too was lead to believe all you had to do was stick a mesh box here & there and they would all mesh just fine!!, Not true, never worked for me.
I also scrapped using omni's completely, so stop wasting your time, get sectors, less noise, less service calls.
Tilt I can tell you now, my Wireless broadband business is now paying for my van, diesel, phone, advertising, light bill, but to name a few. I never ever worry anymore about a LW access point going down. The Pro version has come a long long way since I started 2 years ago. Take my advice, buy it, you will not be sorry. I honour you for getting this far without using the Pro version!!. I currenly get 2-3 calls a day for new installations, the only thing on my mind these days now is more bandwidth. I have gone through everything you have, stick with it & it will reward you!
Paddy | |
bryandj23
join:2002-08-15
Bay City, MI
1 edit | Tilt...
You say that you've got 5.8Ghz backhauls in place on your LW mesh, yet you're using the free version? I'm curious as to what type of cards you're using for 5.8. It was my understanding that most 5.8 cards are Atheros based, and the free version of LW does not support the Atheros chipset.
I too have been running LW, although I have not gotten past one node, for the simple fact that my deployment requires the star configuration, rather than a "real" mesh. I've had my own problems with the setup, one of which I even had Jon Anderson connect to my node and fix some settings for me, only to have the same problem again within a few weeks. (Users who were assigned automatic MAC address authentication were getting their bandwidth dropped down to the "public" class, rather than "owner" class.)
My home brew mesh node has been running for just over a year now, through sub-zero Michigan winters, and 90+ degrees in the summer with no issues hardware wise.
EDIT: I also like the idea of a LW user's forum. The mailing lists don't work, contacting anyone from LW isn't timely. I'd be one of the first to sign up.
Getting back to my question though; what are you using for 5.8 cards under the free version of LW? | |
Bigpaddy_Irl
join:2005-12-12
Ireland | Yes I meant to ask this question too! | |
tilt
Premium
join:2003-04-11
USA
1 edit | reply to tilt
I basically put up 11 nodes before realizing the single radio topology using omnis isn't the most efficient way of doing things. I had them all running on the same channel, same SSID. What began happening was one node would reboot, and a customer's CPE would lock onto some other node, too distant for a reliable connection. When the nearest node to them came back online, their CPE would stay on the poor connection until they reset the CPE. VERY large pita for that customer.
The 5.8ghz solution for me came by using Tranzeo TR-5 ptp radios. (2) between my office and the first tower, (2) between that tower and the next, then another (2) between two other towers. Like I said, each location isn't on the backhaul. Some are just repeaters.
I just connected the backhaul radios at locations that have them, and the nodes at those locations, all to the same switch. assigned static ip's to the nodes at those locations, making them gateways. The ptp radios are transparent, so it just gets me gateway nodes o0ut further into the heart of the network, so data isn't hopping through (5) mesh radios on it's way to/from the internet. I was told that could be done also, that badwidth would not be halved at each hop running through mesh radios, but yes, it is.
Wish I had more to tell you guys on whether the dry antennas helped out much, but I opened the first new antenna yesterday to find Pasadena Networks had shipped them with 3.75" u-bolts in each box. NOT GONNA WORK. I was thinking "Who would want to mount their antenna on a mast that's smaller diameter than the antenna itself?" I would have been left with about a half inch between the clamps. I have more of the Comet GP-24-3 arriving in the morning, as being tomorrow is supposed to hit 38F, and we won't see 30 again for a few weeks, I hope we get them all deployed. Not looking forward to the 50mph wind gusts at 130', but I'll survive. I'll keep you posted. | |
bryandj23
join:2002-08-15
Bay City, MI | I sorta figured you were using a second product outside of LW to do 5.8Ghz. Thanks for the info! | |
tilt
Premium
join:2003-04-11
USA
| reply to tilt
Update:
I replaced 6 antennas Wednesday, along with the cables. As I described, I had stuffed foam around the cable at the bottom of the mounting tube to protect the cable from wearing on the edge of the tube. This caused one installation to hold water in that tube, drowning the N connector. The first thing I did at each site was pull out that foam. None of the rest were holding any water, but I replaced the cables and antennas anyway with brand new. I did see improvement in the signal on these installations, and all is well. On one site, when I pulled the foam out of the bottom of the tube, the cable came with it, like it was barely attached to the N connector up inside. Hopefully they will hold up, as I caulked around the top where the antenna seats into the tube, and the set screw.
I'm considering using that 3M adhesive lined heatshrink tubing in the future to seal all coax connections. I hesitate though, thinking it may make it a pain to disassemble when/if any future dissaembly/replacement is required.
These omni antennas seem to work fine, but I am looking at trying to use sectors in the future, it just adds so much to the cost of each installation, needing 3 radios/antennas at each site. | |
superdog
I Need A Drink
Premium,MVM
join:2001-07-13
Lebanon, PA
| said by tilt  :I'm considering using that 3M adhesive lined heatshrink tubing in the future to seal all coax connections. I hesitate though, thinking it may make it a pain to disassemble when/if any future dissaembly/replacement is required. You will not have a problem doing this. Just put a few wraps of electrical tape around it first and then the shrink tubing. With the tape underneath it, is a snap to just make a slice down the length and then peel it off. 
--
»www.wavecrazy.net Join WISPA today! »www.wispa.org/ | |
tilt
Premium
join:2003-04-11
USA | Thanks, I gotta try that stuff. | |
Ketcham
join:2005-11-02
Wappingers Falls, NY
| reply to Bigpaddy_Irl
said by Bigpaddy_Irl :Take my advice, buy it, you will not be sorry. I honour you for getting this far without using the Pro version!!. Where did you purchase Pro software? How much does Pro version cost? I can't find anything on LW site about where to purchase. The download section still have free version.
Are you using Pro version on your Wrap boards with 5.8/or 2.4 cards?
| |
Bigpaddy_Irl
join:2005-12-12
Ireland | You have to contact business at locustworld.com to purchase it. | |
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