We have a problem here that can''t be solved by our dealer, nor did I yet have an answer from the antenna's manufacturer.

We have three rb112 based dual Atheros AR5212 radio's set up on distances of 600 and 700 meters with proper fresnell space. The idea was to have one of the radio's on each unit/rb performing a P2MP backhaul in the 5,x Ghz band.

Our dealer adviced Hyperlink HG5411P 11dBi Antenna's for this. But in contrary of their advice it seems these antenna's don't work on frequencies in the 5Ghz band on distances more then 10/15meters. (Tested on these distances with good result.) On the mentioned distances of 500/700mtrs they don't see eachother. Not even with a snooper run.

These antenna's for the backhaul are vertical polorized while the AP antenna's on the same rb's are connected to Hor. pol. sector antenna's.

By accident we found the antenna's working in 2,4Ghz band!?! We have the backhaul now running on a 2,4Ghz frequency but the 700mtr link has around -90dBm readings and link sometimes goes down and has overall low speeds. If TX output is set lower then 20dBm the 700mtr link goes down.

The dealer still defend their advice because the antenna's are manufactured for the 5Ghz band and they claim to have several networks running on these configs.....
We have tested all three Antenna's several times on several frequencies and with different setups. No result...

Hyperlink is not exactly promoting these antenna's for outdoor use so herein might be an answer to our problem?

But I'm still not sure if we have not overseen any config's on the rb's?
I just red a document about the software packages. Amongst them is the "RadioLan" software package for support on 5.8GHz RadioLAN cards. I found it is not installed on our router boards. Might this be the problem?
But the antenna's did work on short distances? We haven't a cluen nor does our dealer.

Any one has any suggestions?

Do you have the correct antenna connector selected ?

Those antennas seem to be 5.4GHZ, not 5.8GHZ.
Not sure what frequency your radio card are set for...

SMA

But the antenna's did work on short distances?

To be honest, I would not put too much into the fact they seem to be working at those short distances, as the cards themselves could probably manage that without any aerial attached.

Based on your test results, I would say you got 2.4GHz antenna incorrectly sold as 5GHz...

Even a 5.8GHz antenna will work in 5.4GHz, but you'll lose a few dB's...

To reply on some of the suggestions given...

- Yes, we did check the connector. Although the signal strength is marginal on short distance we tested on longer distance and verified which antenna was to be a or b. The dealer who sells MT boards in a Casing an selling as 'LoboMetrics' couldn't tell us!

- Yes, I also found that the radio's pick up signals evern when the connectors are shielded with alupaper!

- Yes, we checked the proper working freq. band of the antenna's. They are Hyperlink and I think they don't make many mistakes.

- We found discrepancies in the working frequency range between the antenna's and the radio's We found that our advices antenna's are just working in the gap between 5,4 and 5,7Gz which the radio's just don't!
Another stupidity of our dealer.

I still find it peculior that our link does work (although a relative short distances, 500 and 700m trs.) on frequencies in the 2,4Ghz band.
I think it has to do with the duplication factor of the antenna's and the wavelength of the frequencies.

We need parabolics for the proper frequencies.

Can anybody tell me if the 112rb are capable of transmitting in frequencies in the mentioned gap?
I found we have not the 'RadioLan' software package installed. Do we need that for this?

rgds

Rudy

"Although the signal strength is marginal on short distance...." should read "Although the signal strength difference is marginal on short distance....

Those antennas seem to be 5.4GHZ, not 5.8GHZ.
Not sure what frequency your radio card are set for...

SMA

OK, antenna specs are 5150-5350Mhz. I found country settings of the rb112 that have these freq.'s.
I put 5300Mhz in on both sides, all other Wireless settings checked but no contact! A 'Scan' run on either one doesn't show the other. A 'snooper' run doesn't see anything.... You would start thinking the radio's don''t work on these freq's.
But, I've tested them on very short range (10 meters) and then they did see eachother! Even on a freq. in the 5Ghz that later we found out is not exactly withing the antenna spec. range!
And how is it possible that these radio's can see eachother when they are on a 2.4Ghz frequency????
I can understand they will see eachother because the 2,4Ghz waves are roughly 2xwavelength of the 5Ghz range. The radio's are capable to pick up and produce these waves!
But then they should much better pick up the radio waves of a frequency that they are made for!!!!

What is going on here? What are we overlooking???

Power output? We set them on 20dBm for all speeds. 17dBm is default and should work on this distance (500 mtr) but 20dBm is better.

Fresnell zone? Antenna's are high enough. The fresnell for the 5Ghz is smaller then the 2,4Ghz so that should not be giving problems, on the contrary.

We are puzzled and it seems nobody knows the answer....

We are in the process of obtaining better 5Ghz antenna's to see if that might help, but what if the radios are not configed properly?

Has anybody any suggestions?

I think i now the problem try to get 2 pcs of new Radio cards.
it sound that you have broken diversity chips on your cards.
i have hade that problem like 100 times now . and it depends on the verry ESD sensivity CMOS chips, that get blown.

//Rickard

PS Im using that antenna that u are using and that works good.

I have the same problem! My RB532 with R52 card and 5.7-5.8Ghz, 13dbi omni does not function at 5.7-5.8Ghz but works at 2.4Ghz range. These are new equipment freshly order directly from MikroTik.

See http://forum.mikrotik.com/viewtopic.php?t=10466 for details

I think i now the problem try to get 2 pcs of new Radio cards.
it sound that you have broken diversity chips on your cards.
i have hade that problem like 100 times now . and it depends on the verry ESD sensivity CMOS chips, that get blown.

//Rickard

PS Im using that antenna that u are using and that works good.

Tnks for the suggestion. But I've three units and they are all brand new. Two of them are high in a mast and it's a bit complicated to get these units out.
What do you mean with "broken diversity chips" and "ESD sensivity CMOS chips, that get blown"? Why do they get blown?
Your remarks don't make me very happy!

[quote="dapsyra"]I have the same problem! My RB532 with R52 card and 5.7-5.8Ghz, 13dbi omni does not function at 5.7-5.8Ghz but works at 2.4Ghz range. These are new equipment freshly order directly from MikroTik.


Did you already solve your problem?

No! Problem not yet solved. I sent support request to mikrotik and I am yet to receive any response from them.