I have a problem that hopefully someone out there can give me some advice on... this is not directly related to the mikrotik OS or the routerboards, but the problem did not exist prior to using them, so i thought I would ask here and see if anyone else has come across this...

I migrated from a few YDI wipops, which had an lucent/avaya ap1000 mounted at the based of the tower in a weather proof enclosure, then to a power injector, then LMR600 up 100' or so, to an amplifier powered from the injector, then to an 12 db omni antenna. This was ok...
Then I came across mikrotik, and fell in love and started switching towers out. All is running GREAT, except any tower that has an OMNI directional antenna blows cards very often. When i say blows, i mean the reciever basically goes out, but the transmit still works, as i can see the device from a netstumbler scan on a laptop, but i cannot see anything when i do a scan from the tower. I swap the card out and bingo... all back to normal.

This does seem to only occur during an electrical storm (lightning) but they have never recieved direct hits, and I have tried them with and without surge supressors. Also tried some other high dollar polyphase blockers... no luck...

I now mount the mikrotik at the top near the antenna (within 10 ft or so) without amplifiers, and then run a shielded CAT5 down to the base for power and configuration.

All towers that use sector panels... work fine and I have never lost a card on any of them. I started changing out the OMNI's to sectors and so far, I haven't lost any of those that were switched, through the last 5 or more storms. However every storm i still lose the omni's that are left (only 1 left as of today, there were 10 or so before) I went through probably 30-40 SR2 cards so far because of this problem.. so it was getting expensive.

Also wanted to note i tried running a seperate ground from the box, antenna, and surge suppressor straight to a ground rod and that didnt help either.


I know this was a long winded explanation and I may have confused everyone, but if anyone has run into this or has any suggestion, I would sure appreciate it!
I like being able to pop omni's up here and there at a low cost, but not at the cost of 40 SR2 cards, plus the time and labor to change them out...
and the sectors are too cumbersome to use in some areas, and get full 360 coverage.

Thanks in advance!

Use :

- DC Grounded Omni
- Use Ethernet surge protector

- Ground your :
- board
- enclosure
- antenna mounting
- etc.


Thx
//Budi

I have a problem that hopefully someone out there can give me some advice on... this is not directly related to the mikrotik OS or the routerboards, but the problem did not exist prior to using them, so i thought I would ask here and see if anyone else has come across this...

What antenna and what radio card?

Sounds like a PacWireless omni. If so, we've had the same problem.

Changing antennas will get rid of the problem as in receive drops by 20dB after a storm.

George

Yes most of them are pacWireless, 3 of them were older YDI antennas, that had been deployed for 1-2 years already without any problems, but they did not blow near as often as the pacwireless.

What brand/model of antenna did you switch to? I am willing to try another, although i am a little gunshy...

sometimes recieve woul drop 20dB like you say, although occasionally it was much more.

the card were all ubiquiti SR2's origianlly, then i tried some NMP-8602's same thing happened though.

Yes most of them are pacWireless, 3 of them were older YDI antennas, that had been deployed for 1-2 years already without any problems, but they did not blow near as often as the pacwireless.

What brand/model of antenna did you switch to? I am willing to try another, although i am a little gunshy...

I'm back to using the Superpass 2.4 8dB Omnis. Only had two problems in four years of use with fifty in the field, price is very reasonable and they deliver the gain they advertise. Don't know why the PacWireless cause problems, but they do. Pity, the mounting hardware is great.

George

I talked with PacWireless about these antennas, OD24-12, and the engineer believes that there may have been a manufacturing problem with them, and they were not built with DC grounding as they were supposed to be... he is going to verify it and then let me know what needs to be done.

I'll let you know what he says for sure ....

Talked with them just a few minutes ago.. seems there is a defect in the mfg of the antenna, and I was told to RMA them. So if anyone else is experiencing this, you might contact pacwireless, or your distributer regarding this. He told me they were going to rework the product and wasn't sure when they would have the replacement product out.
this only applies to the OD24-12 Omni 12DBi Antenna.

jparsons, please shoot me a e-mail to discuss a very similar problem I had. I may just have a cure for you. mail@moorelandisp.com Thanks Kenny

jparsons.
Any new updates on your problem? Would like to here your cure.If you found one.

No definate fix yet, but, I haven't tried it yet ... I just recieved a couple of new antennas, a 9DB PacWireless that the engineers said is grounded properly, and one from a 12 DBi Commercial grade one from radiolabs.com that they say is grounded properly too, I am going to try them both out, I have a setup going up this week, ill keep you posted....
may take a few days / weeks to know for sure.

the first electrical storm will tell me for sure, I couldn't make it thorugh one before...

I have been having this issue at a new AP I put up about 2 weeks ago. The site is using a 15dBi omni from Pasadena networks(don't know manufacturer). My other 9 APs are using a 15dBi omni from hyperlink (no issues), and the 1 other site is using a 15dBi omni from Pasadena networks.

I have lost 3 radios at a new site (only on the omni, the other radio is fine and continues to operate a 24dBi grid).
At first I just thought it was a failed card, but now I have lost 2 during a small t-storm. These are small t-storms for my area. The sites have not been hit, nor to my knowledge has any lightning hit close to the site. Most of the lightning is overhead. I am at a loss for what is causing this, I am going to change card and omni today as soon as weather clears.

My two theories are currently, wind induced static electricity builds up on the omni and discharges into the card. Or overhead lightning is inducing a charge in the omni and discharging into the radio.
If anyone has any solutions please do tell.

I use wifi-link omni anntena 15 dbi and atheros card.. mikrotik
i have to change my card evry time it rains, I hope someone can find a solution to this problem. please advice me what to do

I all. we are having the same problem her in Sweden...
but . we rebuilt the antennas with better grounding, that helps some times. and i reparing the radiocards by removing the Diversity switch in the cards. then the cards working perfect again so pleas do not throw the cards in the trasch cans!.

//Rickard

yes, very often problem with Omni antennas, because, as I understood, they collect statical electricity, until radio gets blown. I've got card blowned almost every week.

I also thought that there is no solution for this problem, but in fact solution was quite simple. I took few meters of cord (wide one): then I wrapped one end around the connector on the antenna (on the place where cable connects to antenna), and another end to lightning rod. So far (5 months) there was not single problem.

I'll try to post some pictures when I'll go on the roof

I all. we are having the same problem her in Sweden...
but . we rebuilt the antennas with better grounding, that helps some times. and i reparing the radiocards by removing the Diversity switch in the cards. then the cards working perfect again Smile so pleas do not throw the cards in the trasch cans!.

Please tell us how some pictures schematic can you??

And about the static problem I HATE PacWireless Omni ants, I switched to homemade 17db waveguide and AMOS ANTENNA

web site is on Serbian language but you'll get around and there is some english links to sites and people who tried to make this great antenna for few bucks.

And something more I thought I was only guy on earth to have problem with static electricity , you dont need to groung the antenna if its hard to achieve, but antennas must be mounted on the same pole or whether you mount them all the antennas ground elements have to be connected to each other (not the ground but all antennas together) and you'll have less mailfunctions and problems... Ofcorse you cant put 100 ants on the same pole but if there is more than one antenna on one mounting pole there has to bo a good connectivity to mounting pole both antennas ground elements have to be conected to mounting pole better connection longer the cards live

Just think about the number of radios that have been killed by these antennas that we know of here on this forum. Now just think how many we don't know about.

Do I smell a class action lawsuit!

Just a joke guys.....

I don't know about the law suit, because i use Trendnet TW-503PI, and it was always replaced under warranty, although reseller was suspicios what are we doing to those cards

So, anyway: Pacific Wireless should be informed about this problem, because it's a MAJOR problem, not some minor bug. There are "tweaks" how to prevent this, but anyway, this shouldn't happen.

And about the static problem I HATE PacWireless Omni ants, I switched to homemade 17db waveguide and AMOS ANTENNA

web site is on Serbian language but you'll get around and there is some english links to sites and people who tried to make this great antenna for few bucks.

Yes titius, we know there is a lot of better antennas, but what about us who bought 30 pieces of those antennas? Replacament with other antennas, which don't cover full 360 degs is not a solution. Pacific Wireless should fix this.

anyway

Rickard please can you tell us how do you change diversity switch

Yes titius, we know there is a lot of better antennas, but what about us who bought 30 pieces of those antennas? Replacament with other antennas, which don't cover full 360 degs is not a solution. Pacific Wireless should fix this.

if that antenna is not omni ... 360 ... then send them back to ... netiks ?:)

Talked with them just a few minutes ago.. seems there is a defect in the mfg of the antenna, and I was told to RMA them. So if anyone else is experiencing this, you might contact pacwireless, or your distributer regarding this. He told me they were going to rework the product and wasn't sure when they would have the replacement product out.
this only applies to the OD24-12 Omni 12DBi Antenna.

oooo ooo, i have one customer, change the radios 3 times, he have pacwireless od24-12 omni, when rain soft or hard, loss EIRP,

i have this problem now, in this month

yes, very often problem with Omni antennas, because, as I understood, they collect statical electricity, until radio gets blown. I've got card blowned almost every week.

I also thought that there is no solution for this problem, but in fact solution was quite simple. I took few meters of cord (wide one): then I wrapped one end around the connector on the antenna (on the place where cable connects to antenna), and another end to lightning rod. So far (5 months) there was not single problem.

I'll try to post some pictures when I'll go on the roof

please give me a photos here, i want to see how you fix this problem.

Best Regards

I don't know about the law suit, because i use Trendnet TW-503PI, and it was always replaced under warranty, although reseller was suspicios what are we doing to those cards

So, anyway: Pacific Wireless should be informed about this problem, because it's a MAJOR problem, not some minor bug. There are "tweaks" how to prevent this, but anyway, this shouldn't happen.

mmm i have lost 3 radios, and use the antenna od24-12, in 2 months

Well I hav etried several different antennas now, and i still have the same problem I am going to try something suggested to me, and run a piece of heavy gauge copper wire up the side of the antenna, and run that to a good ground.

anybody have any comments on this?

what do you think this will do to the signal or reception of the antenna?

also, I have a box full of about 30 of these blown cards now, if someone has a fix for them... I would love to see example or have some instrucitons on how to repair them.

Jparsons, Give it a try!! 75days uptime through several T-storms! Best piece of copper wire I ever installed. Will try to get you some pics in a few days as I will be climbing silo to add 900mhz to the mix.
Any cure for the broke cm9's????

Jparsons, Give it a try!! 75days uptime through several T-storms! Best piece of copper wire I ever installed. Will try to get you some pics in a few days as I will be climbing silo to add 900mhz to the mix.
Any cure for the broke cm9's????

yes please give a photos

thanks in advance

Same problem here with "no brand name" omni's 8 and 12dbi

replaced them with 8dbi Stella doradus and not had any problem again.

had a lot of discussions with manuf and on the forums, no one did believe it, but i tried 8 radios on two of those 12dbi type antennas and all blow up with rainy weather like you guys say, after changing grounding several times , routerboard, pigtails etc, we at last replaced the omni for other brand and problem was gone.

i use the broken radios in the test systems witch are very close to eachother with signal strenghts of -80 to -90, and works great for testing new config before uploading to the real towers

I've fried over 20 SR2's with omni's.. Before I finally came up with a very simple yet effective fix..

Promise not to laugh..

Cheapo grounding rod with a few peices of stranded wire soldered to one end.. I clamp the other end to the top of my tower sticking about 1ft over the top of the onmi. I then fan out the stranded wire so that it looks like a pom pom on the end.. If my structure is not grounded then I run a ground wire to the grounding rod at the top. If the tower I'm using is already grounded then I don't worry about running an extra grounding wire.


I recently tried a new way of doing the same thing.. I take a small gauge ground wire and run it down the omni making a couple twists along the way to keep it in place. I then take some stranded copper wire and solder it to the end of the wire. I fan it out the same way I did with the larger wire above..


I've been using both setups for several months now and have not lost a radio since. I was losing a radio almost every storm before I started installing these.

-Gerard

You are my hero!
That is exactly what i am going to try too, fairly soon.
mwi, suggested teh same to me, and I havent had a chance to implement it yet, i had already cahnged all but one tower to two 180 sector antennas, which i didnt want to do, but it was the only thing working. the one tower i have left with an omni is hurting right now, but only has one cusotmer on it and they live underneath the tower. thier signal sits at about -80 but they are on.. so i am going to try this out on it, and if all goes well. I will report back here.

Gerard, did you try it without the "pom,pom" on top and did it not work? or just wanted to overkill it right off the bat and not have to worry about it?
Did the copper wire seem to hurt the signal levels any?

Also, I would like to know how to "fix" the blown cards if anyone knows.

Gerard, did you try it without the "pom,pom" on top and did it not work? or just wanted to overkill it right off the bat and not have to worry about it?
Did the copper wire seem to hurt the signal levels any?

No I never tried without it. I tried to replicate the expensive static dissapaters I saw tessco selling.. I tried several different materials for the pom pom but the copper wire worked just as good as everything else I tried.

I didn't notice any decreases in signal strength with just the copper wire.

I did notice if I placed the thicker grounding rod version directly agianst the omni the customers on that side would have slightly less signal (1-2db). however If I moved the grounding rod 6" away from the omni there was no noticible loss of signal.

-Gerard

I can add my pile of cm9's to the list

Thanks for the tip on using the copper wire, I will try this.

Do the R52's suffer from this as much? I assume that would but it would be intresting to see.

Nice tip, Gerard. Those aren't cheap to buy commercially. I'd never thought about using one on an omni!

With cards broken in this way i have found that you can most of the times measure and check if the diversity switch is faulty.

Do this at your own peril!!!!!!!!!!!!!!!!!!!!!

If you measure after the capacitor closest to the ufl connector you are supposed to measure very close to 50 Ohms. Most of the cards that have died due to static measure well below that. (3 to 25 ohms)


Take the whole card and preheat to abot 40-60 degress in a oven.
User hot-air solder tool to heat the whole diversity switch. The diversity switch have got quite a huge earth-plane (Thats why we pre-heat)
Do not use a high air-flow as you will blow other smaller components off the board

Remove diversity switch completely and wire the 2 points with single strands of fine wire.

Hope this helps!

any pics or more info on diversity switch removal? Thanks

Connect Pins
TX to A1
RX to A2

The TX & RX pins are the ones closest to the ufl Connectors.
Diversity switch disabled!

This should be a picture of the switch:



seandsl
--

can someone add the nice drawing again ?, seems to be gone

Thanks ! , i can see its back

Think the method of wiring the Rx and Tx straight will only work for the cards if you plan them to use for N-stream/ only Tx or Rx mode.

for normal use of only one antenna connector you HAVE to use the diversity switch i believe, and were to get those ?

numbers on the chip are 512 / 3011 / 21, no brand or anything else.

can someone confirm that only diversitychip is broken ?, and the card has its original receive sensivity on the Rx port when wired straight ?

we have a number of the pac wireless antenna's out there, and we've only lost 1 radio... it was on a tower we *forgot* to put on a surge protector... put one on, and we've been running good ever since.

we use a polyphaser AL-LSXM-MA connected to every one of our boxes where the NMale bulkhead connector comes out of the outdoor box, connecting to the antenna cable. we ground the polyphaser to the tower with a short ground wire... we had a near strike once at a tower, blew out all the polyphaser's, (had about 20db of loss through them, as opposed to the 0.2 it's supposed to have), but we didn't loose a single radio or routerboard. We just changed out the polyphaser with a new one, and all customers came right back online.

Well, as an update, I did just as mwi and gerard suggested, and have now been up for more than 30 days on that tower! for that tower.. that is a record! I did not put the pom pom on mine, but if it looks to be needed in the future I will.

Thanks for all your advice!

also thanks for the pics on the card fix, ill give it a try as time permits...

Well, as an update, I did just as mwi and gerard suggested, and have now been up for more than 30 days on that tower! for that tower.. that is a record! I did not put the pom pom on mine, but if it looks to be needed in the future I will.

Thanks for all your advice!

also thanks for the pics on the card fix, ill give it a try as time permits...

is a very good notice, one week ago, in the roof in a house, a Tranzeo radio, put everything, but no finished) , put Tranzeo Tr-6600, omni 12 dBi hyperlink, and lightning arrestor, but no finished, no grounded.

the radio work very fine, give a 71 dBm, a 2 meters, in two hours, work fine, more later , rain soft, and 15 minutes, the radio lost EIRP,

i have a conclusion about this, my customers, Wisp, have problem with static, when the town is high and have mountain, i have 5 omnis, in sea level 0 meters , never problem, my conclusion is, if you put in mountain and the town is high example 700 meters, the static is more.

in my town is 0 meters and have radios 2 years work fine, mmmmmmmmmmmmmmm

---QUESTIONS----------------


1) NOW YOU WRITE HERE, no put the POM POM in you omni, how you protect ????, where is the magic? why you have 30 days no problems

2), is a good idea, two ground, one ground for the radio and lightning arrestors, and other ground for only the pom pom, i know if use two ground, have differential voltage in ground, but i am not sure, i thinking put only the pom pom with special ground, for only static, if static go to pom pom, go to radio , and go to lightning arrestors, and go inside the booster of the radio, and the radio lost the EIRP ni give more 1 dBm, in 1 meters, is the reason put two ground.

PEOPLE what you thinks ?

thanks in Advance

My appologies, this reply was more for those helping that were familiar with what i was going to try (read several of my previous posts)
I put a piece of number 8 wire up the side of the antenna and about six inches above the top. and secured it to the side of the antenna all the way down to the surge arrestor (i have used the polyphaser as well with the same results FYI) and secured it to the same ground that the rest of the equipment is using.
If i get back up there I will get some pictures.

I am located primarily in Kansas, USA. We are plagued with lots of wind here, and after talking to several people here, and then several radio engineers (some specializing in antennas and design) As i understand it the wind causes static buildup on the antennas, and eventually causes the problem. which would make sense because the problem has happened after just a very windy day with no clouds. I am no expert on the subject, but before in the same position with the same antenna. I would lose a card a week (on a good week) now i have gone 30+ days without a problem, just by adding a piece of copper wire up the side of the antenna.
What i meant by no pom,pom was that I used just a piece of wire without the pompom at the end.

sorry for the confusion.

My appologies, this reply was more for those helping that were familiar with what i was going to try (read several of my previous posts)
I put a piece of number 8 wire up the side of the antenna and about six inches above the top. and secured it to the side of the antenna all the way down to the surge arrestor (i have used the polyphaser as well with the same results FYI) and secured it to the same ground that the rest of the equipment is using.
If i get back up there I will get some pictures.

I am located primarily in Kansas, USA. We are plagued with lots of wind here, and after talking to several people here, and then several radio engineers (some specializing in antennas and design) As i understand it the wind causes static buildup on the antennas, and eventually causes the problem. which would make sense because the problem has happened after just a very windy day with no clouds. I am no expert on the subject, but before in the same position with the same antenna. I would lose a card a week (on a good week) now i have gone 30+ days without a problem, just by adding a piece of copper wire up the side of the antenna.
What i meant by no pom,pom was that I used just a piece of wire without the pompom at the end.

sorry for the confusion.

thanks very much for you very fast reply, very nice solution, really i want see you pictures.

thanks very much

Best Regards

My appologies, this reply was more for those helping that were familiar with what i was going to try (read several of my previous posts)
I put a piece of number 8 wire up the side of the antenna and about six inches above the top. and secured it to the side of the antenna all the way down to the surge arrestor (i have used the polyphaser as well with the same results FYI) and secured it to the same ground that the rest of the equipment is using.
If i get back up there I will get some pictures.

I am located primarily in Kansas, USA. We are plagued with lots of wind here, and after talking to several people here, and then several radio engineers (some specializing in antennas and design) As i understand it the wind causes static buildup on the antennas, and eventually causes the problem. which would make sense because the problem has happened after just a very windy day with no clouds. I am no expert on the subject, but before in the same position with the same antenna. I would lose a card a week (on a good week) now i have gone 30+ days without a problem, just by adding a piece of copper wire up the side of the antenna.
What i meant by no pom,pom was that I used just a piece of wire without the pompom at the end.

sorry for the confusion.

In a windy spot.
My guess is that it is the fiberglass on the outside of the omni building up static. It jumps to the after a certain ammount of buildup.

How to resolve this question?

For normal use of only one antenna connector you HAVE to use the diversity switch i believe, and were to get those ?

Think the method of wiring the Rx and Tx straight will only work for the cards if you plan them to use for N-stream/ only Tx or Rx mode.

for normal use of only one antenna connector you HAVE to use the diversity switch i believe, and were to get those ?

numbers on the chip are 512 / 3011 / 21, no brand or anything else.

can someone confirm that only diversitychip is broken ?, and the card has its original receive sensivity on the Rx port when wired straight ?

How to set to 1 UFL Connector TX and RX

Tks in advance.

Connect Pins
TX to A1
RX to A2

The TX & RX pins are the ones closest to the ufl Connectors.
Diversity switch disabled!

[img]

My appologies, this reply was more for those helping that were familiar with what i was going to try (read several of my previous posts)
I put a piece of number 8 wire up the side of the antenna and about six inches above the top. and secured it to the side of the antenna all the way down to the surge arrestor (i have used the polyphaser as well with the same results FYI) and secured it to the same ground that the rest of the equipment is using.
If i get back up there I will get some pictures.

I am located primarily in Kansas, USA. We are plagued with lots of wind here, and after talking to several people here, and then several radio engineers (some specializing in antennas and design) As i understand it the wind causes static buildup on the antennas, and eventually causes the problem. which would make sense because the problem has happened after just a very windy day with no clouds. I am no expert on the subject, but before in the same position with the same antenna. I would lose a card a week (on a good week) now i have gone 30+ days without a problem, just by adding a piece of copper wire up the side of the antenna.
What i meant by no pom,pom was that I used just a piece of wire without the pompom at the end.

sorry for the confusion.

This is now the beginning of December. Is this stil working for you. We have a similar problem in South Africa. We are about 3000 feet above sea level with a lot of lightning and thunder, also dry weather. We are loosing cm9 and rb52 on cpe's (using wrap board with either radios, 5.8 ghz). About 20 clients for about 2 months, lost about 10 radios so far, mostly in electric storms or some on windy days. I have one client that I loose after each storm, he is on a 36 feet metal pole (with grounding rod) -- see pic. We know the problem is caused by static electricity. We were first using a all plastic enclosure and replace it with a unit that has a metal backplate we we experise the same problem. I am going to replace the radio again today including the copper rod you suggest to see if this will solve our problem.

I am happy to see other's have the same problem and that somehow we should get around this problem. We will be getting Roo enclosures that we are importing from the states and we hope this will help us overcome our problems.

Your comments. (not sure how to add a image? first time posting!)

welcome to the forum! to post an image, you should enclose the image url with the img tag in brackets. if you hover your mouse over the IMG button it will show you. you need the image to be hosted on some server, no uploads here.

----
yes, by post image i think easy to make user forum understood...
again, welcome to this forum.

regards
Hasbullah.com
----

This is now the beginning of December. Is this stil working for you.

Several months have gone by and I have not lost a single card since I first started using the wire/pompom's/grounding rods.. I've found that a single wire 4-8" above the top of the omni seems to be just as effective as the whole pom pom thing I was doing at first.

-Gerard

The problem is atheros chip set . see :
http://forum.mikrotik.com//viewtopic.php?p=60412

We ran a small wire from the top of the omni (no pom pom) to the bottom part of the omni, then to the radio, then to a 6 foot earth rod, problem was fixed for us.

Also, we not see any loss of signal at all (20 clients on that omni)

Equis,
could you send a photo to better understand?
thanks in advance

I think Gerard posted pictures of the setup.

http://forum.mikrotik.com//viewtopic.php?t=9734


I dont worry about the pom pom bit.

We ran a small wire from the top of the omni (no pom pom) to the bottom part of the omni,

the bottom part means the base of the omni where there is the connector

then to the radio

to the ground of the mini pci or to the RB532 board

Could you tell me if you use a surge protection like this http://www.interprojekt.com.pl/minitar- ... p-236.html and if anyone has try to use only the surge protection solve the issue?

thanks
Max

Hello

Yes, thats the part of the omni I use.

Just to the Metal Radio box (thats eather radio inside)

No, I don't use any other surge protector.

Never lost a card since I did this, used to lose every week.

I am very grateful to all on the other thread that talked about it.

I'm not sure why your cards are keep getting fried so many times in same fashion,

but why don't you buy a long surge arrestor that can cover 50meter (it should cost around 700 to 800 USD and install it in a distance from your AP so no more frying stuff.

I even wonder if thunder strike one place more than 10 times!!!

We use gas-discharge surge protectors on EVERY radio on EVERY tower. I have probably 4 or 5 pac-wireless 12dBi omnis in the field, and a few other brands. We've never lost a radio to this issue.

We use gas-discharge surge protectors on EVERY radio on EVERY tower. I have probably 4 or 5 pac-wireless 12dBi omnis in the field, and a few other brands. We've never lost a radio to this issue.

nickb, consider yourself very lucky! I was one too that has had this ESD problem. And I use gas-discharge surge protectors on EVERY radio on EVERY tower. I cannot recall just how many cm9's I had went through in a month from ESD. Since I added the copper wire to the side of the Omni my troubles have totaly gone away. It sounds crazy that this idea would even work, but it did fix of patch the problem. Best bare piece of copper I ever purchased! And I think it has helped others as well.

Regards

Since I added the copper wire to the side of the Omni my troubles have totaly gone away

Could you tell me if you have also notice some difference in terms of signal client, latency, ping time? I want understand if a problem that I have from long time is related a not ground issue + ESD problem.

thanks
Max

nickb, consider yourself very lucky! I was one too that has had this ESD problem. And I use gas-discharge surge protectors on EVERY radio on EVERY tower. I cannot recall just how many cm9's I had went through in a month from ESD. Since I added the copper wire to the side of the Omni my troubles have totaly gone away. It sounds crazy that this idea would even work, but it did fix of patch the problem. Best bare piece of copper I ever purchased! And I think it has helped others as well.

Yes, I'm glad we have not had this problem. Honestly I think that it depends heavily on the climate of where the equipment is located. i.e. humidity, temperature, types of storms, wind patterns, and things of this nature. When I first heard about this issue several months ago, I became very nervious and started watching closely. However, nothing has happened (or had happened before) of this nature. I find it odd, considering that we are in the midwest, and have lots of wind and some pretty heavy duty thunderstorms.

We've lost our share of equipment in storms, but never this specific type of problem.

You are my hero!
That is exactly what i am going to try too, fairly soon.
mwi, suggested teh same to me, and I havent had a chance to implement it yet, i had already cahnged all but one tower to two 180 sector antennas, which i didnt want to do, but it was the only thing working. the one tower i have left with an omni is hurting right now, but only has one cusotmer on it and they live underneath the tower. thier signal sits at about -80 but they are on.. so i am going to try this out on it, and if all goes well. I will report back here.

Gerard, did you try it without the "pom,pom" on top and did it not work? or just wanted to overkill it right off the bat and not have to worry about it?
Did the copper wire seem to hurt the signal levels any?

Dude,
you should not do that.
it looks so ugly when you thousands of volts wrapping around your
antenna. I believe it even generate a gargantuan electro magnetic
power, specially with those curve around the antenna.

just buy simple copper lightning arrestor, the cheap one is around 5 buck
in here. you must hang it totally separately from your antenna. there
must be no shortage to your antenna

This is now the beginning of December. Is this stil working for you. We have a similar problem in South Africa. We are about 3000 feet above sea level with a lot of lightning and thunder, also dry weather. We are loosing cm9 and rb52 on cpe's (using wrap board with either radios, 5.8 ghz). About 20 clients for about 2 months, lost about 10 radios so far, mostly in electric storms or some on windy days. I have one client that I loose after each storm, he is on a 36 feet metal pole (with grounding rod) -- see pic. We know the problem is caused by static electricity. We were first using a all plastic enclosure and replace it with a unit that has a metal backplate we we experise the same problem. I am going to replace the radio again today including the copper rod you suggest to see if this will solve our problem.

I am happy to see other's have the same problem and that somehow we should get around this problem. We will be getting Roo enclosures that we are importing from the states and we hope this will help us overcome our problems.

Your comments. (not sure how to add a image? first time posting!)

Do you have power regulator?
every time there is a storm hitting our tower
our fuse will trip and we have fused everything with
very low amp.
use some online UPS, specially power regulator.
also Use Surge arrestor on each antenna and as well as
Ethernet surge arrestor.

Try to kill every possible way of surge coming to your board.
I doubt if it is your casing that is directly receiving the electric surge.

Hello.
I'm living at the baltic sea and we have exactly the same problems, you described.
At the beginning of the thread it seems, that a "bug" in the PacificWireless-Omnis causes the problem of "loosing radios".
Is this true? We are using Pacific-Wireless OD24-9 Omnis and I wish to know if we can solve the problem by changig the brand. Or is it a problem related to the antenna-type, in this case omni?
Philipp

after three years of consuming PW products, we have concluded that they have less than 2 year lifespan of good quality, after that their product will get corrosion from inside out, their welding point will get loose and the total performacen of the antennas will drop.

recently all 24db grid parabolic that we ordered from PW had mis matched assembly holes. body didn't simply match at screw holes.

Now, if you tell me that it cause card to get fried or the antenna simply drop its quality in short period of time? I wouldn't be surprised.

We had used Hyperlinktech product, they are very good and they have followed standard, and so far we did not have any sort of failure from their products, except surges. however their sales department is very selfish and they treat you poorly and they have limitation on orders for overseas and etc. they only accept wire transfer which is difficult.


good luck

Yes... for the most part it did fix the problem. I have lost a couple cards from DIRECT hits, but nothing like i was losing before adding the copper wire up the side of the antenna (several cards a week), extending it about 6-8 inches higher than the antenna, and then grounding that well to the tower or all the way down to a ground rod at the base. I have also used SP-6 surge suppressors on the antennas, with some luck.

I've noticed that I've only lost atheros cards when there is improper grounding. I usually have a gas tube arrestor closest to the radio, which still seems to not be a guarentee. We have been putting ground kits on all of the coax cable. I would say that one thing has helped immensely. So far I haven't lost a radio to ESD where there are coax ground kits. I'm in NE Oklahoma, so there can be lots of wind and electical storms. Also, many of my base stations are on water towers; and I generally run my own ground wire down to the bottom of the tower to about 2-3 ground rods.

Eric

Hi all,
I have lost 2 wrap2c boards using both mikrotik and Ikarus os due to lighting static, in the close proximity.
I have had to replace the mother boards, but the os on flash, and the wireless cards: atharos 200mw cards have been returned to service without any problems.
yes it can get costly, and not give much confidence to customers.

I think that the esd diodes on the boards do there job and blow!!

Any help with protection appreciated.

Sat dave

The easiest and most effective way to DC ground an antenna is to use a short circuited quarter wave stub at the centre of operating frequency.

http://www.hubersuhner.com/mozilla/prod ... b-princ-qw

Such a stub can be made using a high quality N type T piece, insert into antenna coax at base of omni and attach another N plug into the side with a shorted length of coax.

The stub acts as a bandpass filter to 5.8Ghz, it attenuates signals out of the bandwidth and also provides a DC ground.

However the coax shield needs to be grounded somewhere along its route with a low impedance connection to the ground.


The following applies to those concerned of direct hits.
Ground wires should be attached to the legs of the tower and run alonside the structure to the top. Coaxial cables should run up the centre of the tower and should not come into contact with the legs of a tower.

Ethernet cables the same.

Guy wires should be grounded and run across the top of any ancillary buildings below the tower.
Lightning arrestors fitted to top of tower, ball or spikes.
These are there to prevent the build up of static and to stop the tower becoming charged to the point where a lead off taper might begin.

The tower should have a earth ring around its base and all points tied to it. Points of entries into buildings need to have copper bulkheads which are tied to same ground.

Watch out when using typical 2 pole SMPS units, 2 pole by definition means that their supply rails are floating from earth, it could be that many folk believe that their towers are earthed when indeed by the nature of the type of supplies that we are using in this industry, nothing could be further from the truth.

Simonjpryce@hotmail.com
Wireless Waves.SL (spain)

Hey all, Just a question... I have all of my 2.4ghz Omni antennas Hooked up with the Pom Pom design, Thank you inventor But is this required on the 900mhz Omni's (getting a Pacific wireless 9.2 dbi omni. "8" ft. high)? Using the Ubiquiti Brand Sr9/Xr9.. Just curious becaus im setting up another 2.4Ghz/900mhz AP'S and need to know... Thanks -Jordan

I don't do anything special for my 900mhz omni's and I haven't lost any cards yet..

-Gerard

I don't do anything special for my 900mhz omni's and I haven't lost any cards yet..

-Gerard

Alright Gerard, Thats what i will do then thanks for this good invention. saved me Radios! -Jordan

Johan

Dis die static jong.....

yes, very often problem with Omni antennas, because, as I understood, they collect statical electricity, until radio gets blown. I've got card blowned almost every week.

I also thought that there is no solution for this problem, but in fact solution was quite simple. I took few meters of cord (wide one): then I wrapped one end around the connector on the antenna (on the place where cable connects to antenna), and another end to lightning rod. So far (5 months) there was not single problem.

See above thread from Krunoslav....

We had the same problem - especially on Water Towers (for some reason) and Silos...

All we did was as Krunoslav said - this was ± 2 years ago and we haven't had a single failure since then... en dit reën hier!!! - BAIE...

As an aside - I've noticed that the SR2's and WRG card are way more suseptible to static than others (RB52's).

Hope this helps

//Tanker

I also was having the same problem as was first posted here, a radio blown in 2 weeks at most. Even though I saw a couple of posts where the pom pom was not used, I made one up with the pom pom. Have not lost the radio since then, signals are great and data throughput is just fine.

Thanks to those who found the solution.

tk

I ran a ground without pom pom, just 3 inches above the top, on my 2.4GHz omni as well as my 900MHz. Cheap insurance.

I ran a ground without pom pom, just 3 inches above the top, on my 2.4GHz omni as well as my 900MHz. Cheap insurance.

I did the same, No pom pom just a ground rod about 5 inches above it. been running strong for 3 months... -Jordan

I have had the same problem for around the past six months, so on the 4th of July I did what was suggested in this forum. I ran a copper wire along the length of my Omni’s and about 5 to 6 inches above it on two of my towers. Last night (July 11th) we had a thunder storm come threw and one of the two towers that I made this modification to made it threw the storm just fine but the other did not. The card (R52H in a Rb532A) didn’t stop working, but lost around 15 db gain. I am really getting tired of climbing these towers to replace a card every time we get a storm. My towers, and equipment are properly grounded, and there should be no reason that this should be happening. I will start RMAing all these cards that have failed. If I can’t RMA them, then I will stop buying them. If I can’t find a card that will work properly with out failing due to ESD then I will stop using all MikroTik equipment.

Note to MikroTik ….. You better figure out whats going on soon or your going to start losing customers …. We cant afford to replace out a card every time we get a high wind or a storm.

It's not Mikrotik's fault. It happens to radio cards and cpu boards made by most vendors.

You have a few options..

relocate your antennas below the top of the tower.. or
use a DC grounded omnis.. or
use an XR2 w/grounding strap on your omni antennas..

-Gerard

I don't think its that simple.

We have a lot of towers on granite outcrops, as that is where the high places tends to be.

We have had a LOT of trouble with omnis with no DC grounding, but have got past that pretty well as we junked the un-grounded antennas.

Antenna problems aside, grounding is an inexact science. Grounding effectiveness varies with ground water content and a bunch of other variables that change by location and also change by time of year, and with the price of heavy copper cables today the cost of making a really good tower ground is not trivial.

We had one tower in particular that every time a storm came through we lost radios, power injectors, switch ports or all three above.

We spent a few hundred bucks on some 2/0 copper cable and a couple of good ground plates, dug them into a pair of holes that actually filled with water while we were digging, and haven't had to touch that tower since. I'm not very bright, but if you hit me with a stick hard enough and often enough even I can learn, which is exactly what has happened with grounding and radio failures over the last six years.

The towers on rock with crap grounds blow radios, the towers on soft ground with water close to the surface don't. We are going to spend whatever it takes to fix the grounding issues, then hopefully our trips to fix radio cards will drop dramatically.

We get a huge amount of lightning here, and currently (pun intended) we are double the normal amount of lightning strikes for year to date, so we have to fix this or die.

George

There is something wrong with these cards!!! I use to use Orinoco ROR’s with gold cards and never …. I mean NEVER lost a card!! These cards (SR2, R52H) are way too sensitive. I’m scarred to breathe when I put one into one of my Rb532A on top of a tower!

As far grounding! I didn’t have this problem last year using the same equipment so it has to either be a problem with OS/Driver or a production issue with the cards!

And who the hell decided that it would be cute to put two antenna connectors on these cards anyway… Correct me if I’m wrong but can’t you only use one at any one time anyway? If this is an issue with the diversity chip wouldn’t removing one of the connectors and the chip resolve the issue?

Chris,

Problem solved. I had lots of problems with the Pac Wireless omnis several years ago, 2005 to be exact. I lost Prism radios and other radios during almost every storm. You can either use a DC grounded antenna or put a Polyphaser lightning arrestor on your omni to keep the static discharges out of your radio gear. Not a cheapie! Get a Polyphaser LSXM-ME.

I have not had to replace a single radio to due static discharges since 2006 when I installed all the Polyphasers. Well, except once on a tower where I forgot to install the suppressor. That radio lasted until the second lightning storm before it got it's ears blown out. I've posted here before but people still don't believe me I guess. These things just work, try one at least! I'm guessing people try the $20 gas tube suppressors and no they probably won't stop this type of discharge.

chucka ,

Thank you for your input!

My antennas are DC grounded. But I will order a Polyphaser LSXM-ME and see if that resolves the issue!

Okay, good. When I say DC grounded I mean the internal antenna construction not the mounting of the antenna atop the tower. If you ohm between the center pin of the antenna connector and the outer connector it should show a direct short if it is a true DC grounded antenna. Most omnis are not. I've seen omnis that claim to be DC grounded but they are only grounded through a capacitor. Either way, try a Polyphaser on it, I think you will be pleasantly surprised. I believe it will be your last trip up that tower until you get a direct strike.

AL-LSXM-ME High-Pass Filter Protector


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An update on my little project, the ground running beside the omni works. Survived a strike that hit my electrical ground and fried the POE suppressor and either the ether1 port or the cable itself. Lightning struck within 50 ft of a 200ft tower, didn't blow the diversity chips in 3 radios. Power still works, but no link over the ethernet. AP still works, got a CPE connected wirelessly to feed the system until I replace it.

Connect Pins
TX to A1
RX to A2

The TX & RX pins are the ones closest to the ufl Connectors.
Diversity switch disabled!

can we have the picture one more time?:D

Use :

- DC Grounded Omni
- Use Ethernet surge protector

- Ground your :
- board
- enclosure
- antenna mounting
- etc.


Thx
//Budi

may i want use sepearte earthing wire for all things or same ground is enough