Reduced Noise Floor on HG3-TP-A60 60° using Mikrotik RMB11G + M11G miniPCIe

[n21roadie]

I have noticed that on 3 X RF Elements TwistPort Adaptor RBC for RouterBoard+RF Elements HG3-TP-A60 60° + Mikrotik RMB11G + M11G miniPCIe there is reduced noise floor -60 ?

Also noticed if I leave the frequency usage run for say 30mins the -60 frequencies listed will increase up to 8 from 1 and vary from these numbers, I counted a total 20 X -60 listed (5200-6000 scan ) 

As there is 3 horns with same problem is there a design issue with the horns?

 

 

 

 

Edited December 6, 2020 by n21roadie

[Tom]

Hello, horns, as any other antennas are passive devices - they do not produce any signal, or noise. Any and every signal merely passes through them. This must be something with the radio, have you checked MikroTik user forum for similar issues?

[n21roadie]

Hi, when there is 3 horns that are pointing in 3 different directions and have similar issues this is most confusing? 

(1) Why all at noise floor numbers at -60dBm, why not some at any other levels  ?

(2) A scan from a CPE pointing in same direction does NOT have any noise floor at -60dBm ?

(3) Of the 20 frequencies listed above at -60dBm only 3 are used on other AP's at the site the remaining 17 frequencies are not used?

(4) We have already replaced Mikrotik RMB11G + M11G and unfortunately same issue?

(5) I had posted the issue on Mikrotik forum and so far haven't got any replies to pin point the issue (https://forum.mikrotik.com/viewtopic.php?f=7&t=169254 )

We have another horn at another site but as its in live production I will have to wait until traffic is reduced to do a frequency scan.

 

[n21roadie]

I have done another Frequency usage from another site and once again Noise Floor of -60 (attached screenshot !) , i had to conduct a quick test as it was a live production site!

Something is seriously wrong with HG3-TP-A60 60° as this is occurring on 4 horns (3 at one site, 1 at another site) 

We also use Mikrotik RMB11G + M11G combination onto RF elements SEC-CC-5-17 sectors but once again they are in live production, so i will have to wait for off peak time to test!

[Tom]

I understand your situation - it is very strange to see a behavior like that and I am sorry you have to deal with this. From the antenna physics standpoint - there is no way the issue you're experiencing is caused by the antennas. A simple test would be replacing the antenna in question with anything you have - non RF elements antenna - and see if you're getting the similar result. If so, then you can be sure it is the radio.

The 5 MHz channel seeing -60 dBm noise while the neighboring channels see -95 dBm noise floor strongly point at the radio. Please do try the simple test and let us know about the progress / if MikroTik forum helps.

[n21roadie]

Update - The -60dBm noise floor is appearing on all RF Elements Antenna's 60° + 30° + SEC-CC-5-17, at this stage I am thinking that the issue maybe a Mikrotik ROS software glitch because the -60dBm is appearing on live production devices and they are working flawlessly since put up in the spring this year,

I did some frequency tests

(1) 20Mhz scan : No -60dBm,

(2) 40Mhz scan: just 1 result -60dBm

(3) 80Mhz scan : 2 results -60dBm,

Back to Mikrotik support to comment on this issue?

 

[Tom]

Right, the fact that you get the same -60 dBm regardless of the antenna strongly points towards an issue with the radio or its software. Definitely contact MikroTik support.