need your support

RouterOS Wireless Networking
1

hellow my friends
i have ominantenna 15 dbi+groove mikrotik 5 ahn
there is a user far from my access point above about 500ms.he use nanostation 5 ghz he have ( -60 signal strenght .. 75% ccq )
i put another ominiantanna ( hyperlink 12 dbi+routerbord433+xr-5 mini pci) .. this omini is far from the first about 10 ms …
the both antennas are with 15 ms elevation..
now..if i make that user to connect with the second antenna he have ( -75 signal strenght…40% ccq )!!!
i changed the frequences of wireless..but without a benefit !!!
is there a wrong !!!

please need your support
My thanks and appreciation

2

make a simple network diagram, I don’t understand the problem right now. and 15ms is meters? why do you call that “far” :slight_smile: ?

3

thank you very much my friend…( normis )
i will put a network diagram

4

hellow my friends
the antenna 1 = ominantenna 15 dbi+groove 5 ghz ahn
the antenna 2 = ominantenna 12 dbi + mini pci xr-5 + routerboard 433

Theoretically the transmitting power of antenna 2 is very stronger than antenna 1 due to its 600 mw mini pci xr-5
but in fact the opposite is happing to me
i mean the remote client ( = nanostation 5 ) is recieve signal from antenna 1 better than 2
i changed the frequencies on both antenna but the result is disappointing
i hope you understand me this time

5

check if u r using the xr5 at optimum power.
thr can also be some antenna or pigtail issue causing more db loss hence higher signal from ant-2

because i have a link with xr5 at one end and groove at the other and my signal level is -58/80 tx/rx

6

check if u r using the xr5 at optimum power.

but how can i chek this parametrs ..all i know that i have the setting down
on the antenna 2 ( with xr-5)

7

Looks loke you second antenna or pigtail or card is broken

8

The difference can also be explained by another effect:

Ant 1: 200mW=23dBm(groove)+15dBi(omni)=38dBm EIRP at the antenna
Ant 2. 600mW=27.8dBm(Xr5)+12dBi(omin)=39.8dBm EIRP at the antenna.

I take in respect the coax and pigtails used on both is the same quality and length.

From 38 to 39,8 is about 65% more power radiated from the antenna 2.
But because of the characteristics of this antenna (lower dBi) its signal strength is lost over distance faster than that of ant1.
The higher the gain an omni antenna has, the smaller the energy bundle is focussed in a vertical pane. Thus over the same distance compared to a lower gain omni (that has to cover a greater vertical pane with its energy) it will hit a distant antenna with more energy.

So I would expect signals to be more or less the same in your case. But only a proper link budget calculation with all the relevant parameter and characteristics of the the antenna’s and cable etc. will give you a decisive conclusion.

Another effect that could play a role here is in the case the antenna 2 is directly in front of the ant1 seen from the remote client. Now antenna 2 might have an influence on the signal pattern radiated from antenna 1 towards this client.
It can be that the antenna starts to work as an oscillator (because its made to work in the same frequency) and thus increase the signal in certain directions.
It might also be the radio waves from ant1 are a bit obstructed by ant 2 and behind it you get waves that sort of bend around that antenna 2 and hit each other creating a standing wave with black and hot spots. If that remote antenna now is in the hot spot it will receive more energy than normally.
(Look at is as an island in the path of a tsunami. The wave can get almost twice the size behind the Island as it has on the front!)

But nevertheless check cables, pigtails and radio. Because the other suggestions might be proven true too! :smiley:

9

I take in respect the coax and pigtails used on both is the same quality and length.

the omini with groove have no any cable .the omini is connected directly with the groove
but wait a minute
the antenna 2 have in sequence …omini > coax cable 15 metres >pigtail >mini pci xr-5>routerboard>…etc..
perhaps the proplem is in the lmr cable ( coax cable ) i think it is too long
any one have something to say..??.

10

Here you go!
Lets presume you use LMR400 cable with an approx loss of 0.35dBm per meter, times 15 makes 5,25dBm cable loss. Add this to the sum of antenna 2 and you have 34dBm EIRP which is 4dBm less than the antenna 1 config! Since each 3dBm represent double (or half) the power it means that your antenna 2 setup at the antenna already has less than half the power radiated as the antenna 1 setup with the groove. Together with the different antenna characteristics this explains your difference in signals… :slight_smile:

Conclusion:

  1. your radio’s work fine
  2. It proves valuable to do some math before just sticking a wet finger in the air…
11

thank you very much my dare freind…i will give you a karma
i did the fellowing steps
1- i changed the lmr cable to another shorter one ( 2 meters ) but still the transmission is not good !!!
2- i changed the method of powering connection
i mean from poe type like the image down

by the connection type above ..the transmission is not good
by the connection down the transmission is very perfect ..the signal of the remote client now is -45 :open_mouth: :open_mouth: :open_mouth:


12

laithmikrotik: thanks for the karma.

What you show me here can be very interesting. You show me now that when the board is powered by the PoE cable (So the power comes through the POE ethernet port) you still have bad receipt?
And if you power the board by the jack you have good receipt?
This is hardly impossible to believe…
Because how the board is powered should not have any effect on the output of the radio.

But please check or give some more info now:
Is the voltage supplied to the board by the POE cable the same as when using the jack plug?
What is this voltage anyway? And how long is the cable between board and power supply (battery/adapter?)
Is the board grounded to earth?
What ROS version do you use?

If you can give me this info it might be a finger-pointing into another issue I and many others still struggle with; Ethernet port flapping or disconnections.
I have a strong idea the issues with Ethernet ports, specially the PoE port, has something to do with currents ‘leaking’ over that port when in use.

13

poe cable voltage= 24v
jack plug = 24 v

24v / 3A …50cm becuse the adapter is beside the router box

no

v5.1

14

ok thanks..
Is it possible to repeat the two test while the board is upgraded to 5.8? And what firmware is presently on the board?

sys / routerboard / pr

type this in terminal and it will show the firmware. If there is an old one, first do all the tests with the old fw, even with 5.8 installed.
Than in last instance also update the firmware.

sys / routerboard / upgrade

Do the test again to see if the fw made any difference. Personally I think the error has to do with the firmware.

thanks..

15

when i type the code you want the result is this

16

somthing is wrong with my router board… what does the image down mean !!!
there are no ports ..but i sure i made bridiging between wirless and ether 2 ports.now nothing is appearing
also i dont have any proplems with the clients.i mean the internet is very very good with them
i dont understand what heppen to me :confused: :confused: :confused:

also see the image down..now there are no ip addresses

17

Sorry, made a mistake, the code should be:

system
routerboard
pr

So each word needs to be ended with an enter to execute the command and get a new prompt at a new line.

Regarding the empty windows. This seems to be happening in 5.8 if you are connected to the routerboard by mac.
Give your routerboard an IP in the same range as the PC and log in with winbox by its IP.

18

windows are empty because you connected to the device with MAC address and not IP address, and over MAC the connection is very slow.

19

oh …my god how i forgot that
the result is

20

OK, so everything seems to be fine apart from the fact that your test showed a difference at signal strenghts between if the unit is powered by the power jack or POE?
Repeat that test please again and if the issue is still the same report it to MT support because this would be very weird behaviour…