Upgrading Asus 68U Antennas - Worth It or Not?

[Poseidon]

Is it worth upgrading the stock antennas on the RT-AC68U???

If so, which ones are recommended. Thanks

 

[TonyH]

IMO, not worth the effort. What is your expectation? Gain antennas changes radiation pattern which means it is not omni-directional. Is your router sits at a best location as far as coverage goes?

 

[L&LD]

What is your coverage area target? Single floor? Multilevel? SqFt?

What would make it 'worth it' to you? Better throughput? Less drops/latency?

What devices do you want improvements in? Handhelds (I'd say save your time and money). Laptops (try upgrading the WiFi chip instead)? Other (use two routers in a 'bridge' and 'AP' configuration.

As you can see, it is not whether any specific antennae are 'better' or not. It all depends on your usage, expectations, network environment and your clients.

 

[sfx2000]

Is it worth upgrading the stock antennas on the RT-AC68U???

If so, which ones are recommended. Thanks

Generally no - the factory antennas are a "best fit" for most of the customer scenarios - and then one must also consider the client side...

 

[Poseidon]

Thanks for the feedback guys. I think it's best to stick with the stock antennas in my case as there probably isn't much to gain with "bigger" antennas.

 

[pete y testing]

Thanks for the feedback guys. I think it's best to stick with the stock antennas in my case as there probably isn't much to gain with "bigger" antennas.

however run ethernet or eop and an access point in another part of the house will achieve what you may be after

 

[Erdinc]

I was planning on replacing the stockantennas with 15dBi omnidirectional ones. But I guess I should stick with what I have....

Do you know what the maximum antenna output value of AC68U is?I can't seem to find this info anywhere...

 

[Erdinc]

Generally no - the factory antennas are a "best fit" for most of the customer scenarios - and then one must also consider the client side...

But the factory antennas are 3.5dBi X 3 according to Asus. don't you think they are weak a bit?

 

[sfx2000]

But the factory antennas are 3.5dBi X 3 according to Asus. don't you think they are weak a bit?

They're balanced and matched to the radio design...

If Asus thought higher gain antennas would be better, they would have done it in the first place.

 

[Erdinc]

They're balanced and matched to the radio design...

If Asus thought higher gain antennas would be better, they would have done it in the first place.

I see, thanks

 

[L&LD]

I was planning on replacing the stockantennas with 15dBi omnidirectional ones. But I guess I should stick with what I have....

Do you know what the maximum antenna output value of AC68U is?I can't seem to find this info anywhere...

What you would get by doing so would be an elongated 'donut' coverage pattern but at the loss of height in that coverage area. For a single floor, this is what you need. For most homes with more than one level, it will be a net loss (you will trade coverage for a little further out on the same level as the router at the expense of worse coverage on any other level).

http://www.antenna-theory.com/basics/radpattern.php

The antennae radiation pattern can be changed. The maximum 'output' can't (by only replacing the antennae).

In other words, as antennae become higher and higher gain, they become much more directional too. And the theory doesn't translate into reality either (at least, not directly a one to one relationship). What I'm pointing out here is that if the normal antennae had a range of 50' in a specific environment, it won't have 100' range if you quadrupled it's amplifying effect.

What sfx2000 said about the stock antennae being 'balanced and matched' to the radio is very true. While changing antennae can bring about improvements in a specific case or need, it will invariably also come with a decrease in performance in other areas that may be just as (or even more than), important than simple range too.

 

[sfx2000]

What sfx2000 said about the stock antennae being 'balanced and matched' to the radio is very true. While changing antennae can bring about improvements in a specific case or need, it will invariably also come with a decrease in performance in other areas that may be just as (or even more than), important than simple range too.

One of the challenges with antennas is that most people do not have the tools or knowledge to actually measure the gain or performance of a given antenna - so it's easy for someone to put a product up on Amazon, Alibaba, eBay, etc, and claim they're high gain - and as such, most people will pay the money, and subjective confirmation bias being what it is...

The main site did an article - using Linksys' WRT1900ac with official high gain antenna set provided by Linksys... and there, sometimes improvement, sometimes a big hit on performance. And that's with a kit that was certified by the OEM...

http://www.smallnetbuilder.com/wireless/wireless-reviews/32774-linksys-high-gain-antennas-reviewed

 

[jerry6]

not worth it , I gave it a try and did not get a drop in performance , not sure I got any improvement either . Placement or router and client wil get you more for less money .

 

[Erdinc]

Wow! Thank you all for this world of information and advice. I read them all and also visited the links in your messages, though it is impossible for me to digest all that technical stuff all at once.

Anyways, let me tell you why in the first place wanted to purchase antennas.... I live in a dublex apartment made of concerete including walls. My Asus DSL - AC68U is on the first floor in the study which is on the right end side if the apartment. The wife signal was week upstairs so I mounted a TP-Link RE 210 ac750 to boost the dual band signals. After trying different spots upstairs I finally found the right location that is half way the stairs. Now I have sting signal almost everywhere upstairs - except for the kitchen. However, the signal is still week downstairs in some rooms far from the study. I thought powerful antennas will not only boost the signals upstairs but also downstairs in rooms far from the router. I thought directing one of the new antennas towards the direction of the blind spots would solve my problem. Based on your answers, I might have to buy another range extender for those rooms...

Thanks again for your help,

 

[L&LD]

A quick note about 'directing one of the new antennae towards the direction of the blind spots' part of your post above.

The orientation of the antennae will make a difference (and it has to be the same for both the router and the client).

On a single floor of the area to be covered, a vertical arrangement of the antennae like ||| will give the best throughput and lowest latency (all else being equal) as long as the client's antennae are also orientated similarly.

On two or more floors of required coverage, then a 'W' arrangement like \|/ will be a better solution.

In either case, you want the antennae and the clients to be at 90 degree angles to each other for maximum signal/lowest latency. So test the angle of each of the antennae (in three planes) to determine if you can further boost the signal (enough to make a difference).

So, try to visualize the antennae from the routers like this (single antennae shown for clarity):

/



                                        |

and the client device as parallel as possible to the router's antennae.


What you are trying to avoid (particularly at extreme distances, or with many obstacles in between) is to actually physically 'point' an antennae towards the client.

Below:                                                         Below:

Router                                                         Client

Antennae

Orientation

_                                                                |

The above is how to not do it.

 

[TonyH]

But the factory antennas are 3.5dBi X 3 according to Asus. don't you think they are weak a bit?

15 dbi is quite a jump It should be much bigger in height and omni directional, then how about rsadiation angle. In antenna design it is always give and take situation. 1/4 Lamba has 0dbi as a reference. Theory say 15dbi antenna is not
3/8th or 5/8th Lamba making it longer or coiled element which will have high Q, so no more wide band antenna.

 

[Erdinc]

A quick note about 'directing one of the new antennae towards the direction of the blind spots' part of your post above.

The orientation of the antennae will make a difference (and it has to be the same for both the router and the client).

On a single floor of the area to be covered, a vertical arrangement of the antennae like ||| will give the best throughput and lowest latency (all else being equal) as long as the client's antennae are also orientated similarly.

On two or more floors of required coverage, then a 'W' arrangement like \|/ will be a better solution.

In either case, you want the antennae and the clients to be at 90 degree angles to each other for maximum signal/lowest latency. So test the angle of each of the antennae (in three planes) to determine if you can further boost the signal (enough to make a difference).

So, try to visualize the antennae from the routers like this (single antennae shown for clarity):

/



                                        |

and the client device as parallel as possible to the router's antennae.


What you are trying to avoid (particularly at extreme distances, or with many obstacles in between) is to actually physically 'point' an antennae towards the client.

Below:                                                         Below:

Router                                                         Client

Antennae

Orientation

_                                                                |

The above is how to not do it.

15 dbi is quite a jump It should be much bigger in height and omni directional, then how about rsadiation angle. In antenna design it is always give and take situation. 1/4 Lamba has 0dbi as a reference. Theory say 15dbi antenna is not
3/8th or 5/8th Lamba making it longer or coiled element which will have high Q, so no more wide band antenna.

Yep,I was told here that the higher decibel the antenna the flatter the doughnut .I will first try positioning the router's antennas in the W shape as L&LD suggested to see if the remote rooms will receive stong enough signal. If this does not work, then I might try using 6 dBi antennas to flatten the doughnut a little bit.

 

[ColinTaylor]

Based on your answers, I might have to buy another range extender for those rooms..

Try not to use range extenders unless you have no choice. A much better solution is to place one or more wireless access points around your house. Link them back to the main router with Cat6 cable. If cabling is not possible use powerline adapters for the link instead.

 

[Erdinc]

Try not to use range extenders unless you have no choice. A much better solution is to place one or more wireless access points around your house. Link them back to the main router with Cat6 cable. If cabling is not possible use powerline adapters for the link instead.

Unfortunately, my wife hates cables and cords around , so using APs is out of question. But I understand your concern about range extenders, I guess you are pointing out how they divide the bandwidth to communicate with the clients and the router. Let me know if I am mistaken.


Sent from my ASUS_Z00AD using Tapatalk

 

[ColinTaylor]

Unfortunately, my wife hates cables and cords around

Same here.

so using APs is out of question.

Not necessarily. Depending on your particular environment, you can link the APs to the router using powerline adapters. That's what I do. In fact one of my powerline adapters has an AP built into it so there's no need to wire it to a separate AP.

But I understand your concern about range extenders, I guess you are pointing out how they divide the bandwidth to communicate with the clients and the router. Let me know if I am mistaken.

Yes that's part of the problem. The other is that, as you can see from these forums, Wi-Fi can be problematic even in normal circumstances! Add to that the fact that people are using them because they have a difficult environment, increases the potential for problems (compared to just hard-wiring an AP).

The other issue I've personally come across is the fact that range extenders have to "spoof" the MAC addresses of their clients. The can sometimes lead to problems in certain circumstances. Different vendors handle the MAC address problem in different ways, which means interoperability between vendors can also be a problem.

I don't mean this post to come across sounding completely negative about range extenders. I'm sure they've improved a lot since I last used them. Certainly, if you only want to extend web browsing to a difficult area then they're probably more then adequate, as well as cheap and easy to install. Trying to stream video (DLNA, Netflix, etc.) through one of them is just fraught with frustration IMHO.

EDIT: Something like this might be worth considering. Note that I have no personal experience of this product.

EDIT: As always, Tim has some excellent reviews of wireless range extenders here.