RT-AC87U Terrible RSSI compared to RT-AC66U

[spacemanspiff]

I had a chance to get an RT-AC87U and decided I should try and use it to replace my aging RT-AC66U that I use as a media bridge from my RT-AC68U that runs DD-WRT.

The RT-AC66U connected to my RT-AC68U and reports an RSSI of -56dbm. When I turn it off and replace it with the new RT-AC-87U running latest Merlin WRT, the RSSI is -70dbm and occasionally goes up to -80dbm.

Why is it so god awful terrible? I would have thought it would be the same or even better??? Even the signal indicator shows only 1 bar when it scans for available networks?

 

[kfp]

Which version of firmware were you using on the AC66? Also, have you kept all the Wifi settings the same? Like both using 5Ghz with same channel and width etc.

 

[appleseed]

it's Broadcom vs Quantenna, so different low level closed-source drivers in the mix now:

https://wikidevi.com/wiki/ASUS_RT-AC66U
https://wikidevi.com/wiki/ASUS_RT-AC87U

all things being equal (same firmware, exact same settings, height off the floor, exact same location, same noise floor etc..) you'll have to play with antenna position, and if that doesn't work then downgrading/upgrading firmware. It's trial and error, and not fun, but eventually it should pay off. Get a good wifi signal reader for your phone/tablet which is helpful.

 

[unsynaps]

Just to cover bases was the 87 set up from scratch or were settings files copied from the 68 to the 87?

 

[spacemanspiff]

Which version of firmware were you using on the AC66? Also, have you kept all the Wifi settings the same? Like both using 5Ghz with same channel and width etc.

It's on the final Merlin build from last month before support was dropped for it (380.70). I didn't change anything on my source router (the 68U) and when you are using media bridge mode there isn't really much that you can configure.

Everything is exactly the same in terms of location and positioning. Literally just trying to swap it out.

I see what @appleseed is saying about different antennae, but this RSSI difference between the 66U and the 87U seems like way too much of a discrepancy unless these two antennae/drivers just hate each other.

and for @unsynaps response - yup I factory reset the 87U before and after flashing to Merlin 384.5 and then I configured from scratch.

 

[spacemanspiff]

OK...this situation is getting a little stranger and I think something is really wrong with this 87U. Either from a hardware standpoint or maybe firmware issues?

I've been trying to hop onto different 5GHZ channels to see if it performs better. If I change the channel on my 68U, the 87U cannot automatically pickup the channel change and connect to it. However, my old 66U on 380.70 has no problem detecting and reconnecting when the channel changes.

Any thoughts or ideas on how to determine if this is a faulty 87U?

 

[appleseed]

I would guess 384.5 is the issue then. all should be on 380.70, in my opinion. I doubt the hardware is bad.

 

[Grisu]

>10dB difference can be if one is set to EU and other to US.

 

[spacemanspiff]

>10dB difference can be if one is set to EU and other to US.

Is one better than the other? I didn't see any option to set the regulatory mode in the Asus/Merlin firmware? And really, isn't that controlled at the Parent-AP end and either the 66U or the 87U would just adapt to what the parent-AP is set at?

Oh..and I just tried rolling back to Asus official 3.0.0.4.382_50010 and now the 87U can adapt to my changing the channel on the parent-AP and the RSSI has improved. So maybe all is not right in the land of 384.5 and the 87U. I'll keep testing with legacy next.

 

[Grisu]

EU much less!
It is set to where it is sold in cfe-bootloader, didnt say you could change it on a 87U.

If you use stock-AiMesh and it mismatches between parent and node it will something like default to minimum I think.

But you have merlin (no AiMesh), it has to take what you set, there should be no relation between your devices, except all auto-mode and they choose their WiFi-settings on their own.
E.g. ch. 36-48 or 100-144 much less than 149-165 by regulation.

 

[spacemanspiff]

@Grisu

Sorry...don't quite follow what you mean by 'EU much less'?

Do you mean the EU has less power and therefore less range?

How do I check the regulatory I wonder. I bought it here in NZ.

 

[Grisu]

Do you mean the EU has less power and therefore less range?

simply yes
allowed (or at least set by asus) channels and transmit levels can be very different around the world.
maybe you get it with telnet or ssh: nvram get territory_code