Hello!
I am having a strange situation with one routerboard 433 RouterOS 3.24
There are three wireless cards on it, two of them are on 5GHz and one on 2.4GHz.
One of the 5GHz interface is configured as station, the other as AP. The remaining
2.4GHz is configured as AP also.

Now, when I do a scan from the station interface I see the other card at a signal
strength around -40 and frequency 5200, but I do also see another one, with same SSID and same
mac-address at a signal around -90, but on frequency 5240.
I tried to change mac-address of the interface acting as AP, I tried to hide the SSID
but still teh same situation. Every time I do a scan there are two AP I see with same
mac-address and same SSID, only different frequency and signal strength.

What is going wrong here?
Thank you, Toni

Using 10Mhz or 5MHz channel? If so, this is normal.

No, it is not using 10MHz or 5MHz channel.
Any way why it would be normal on a 10 MHz and 5Mhz?

I have seen the exact same thing with 4.1 and R5H cards. Two cards side by side in a 433AH, when scanning you will see the other SSID leaping across. My assumption is that the "bleed" over to the other channels is strong enough for the scan to recognize it as another channel.

Yes there were a lot of former threads on the forum regarding the same issue. Some say it is caused by "spurs" radiating from one of the cards. Others have different views.

I has seen it for myself too.

The problem is that the "spurs" if they can be called that, will actually allow another device to register with it. I have had that happen.

However what may be common is that those that have experienced the same, have multi-radios within the same enclosure.

As a former RF engineer, I would say that it was expecting a bit much to have one radio card plonked 10mm abother another, and then expect 50db or more isolation.

Why dont you try puting the radio cards in seperate metal enclosures and see if the problem still exists.

There was much debate over this issue many months ago, even with the use of a laboratory spectrum analyser, some other guys had his claims disputed.


I am assuming that anyone who owns a spectrum analyser costing 20,000 quid or more, certainly should know how to use one, yet the poor chap had his findings shot to pieces.

I dont know what the answer is, a trawl through the history of posts and you will find many threads regarding the same issue.

Good luck with that one.

Simon

Thanks guys for your replies, I come to understand that this is some
"leak" of the card itself. Once we know what the problem is
we can provide at the solution after.

One more thing, do you think these "leaks" come primary from below
the card or from above it (where the pigtail is connected)?