RT-AC87U High Gain Antennas

[Veldkornet]

Has anyone tried if the WL-ANT191 High Gain Antenna's with the RT-AC87U? I see on the website it specifically states "for 2.4Ghz networks".... Never knew that mattered for the antenna...

Not sure how these compare to the ones already on the RT-AC87U, but I've had good experience in the past with these sort of antennas on my D-Link Router.

Or otherwise, a good recommendation of ones that would work?

 

[Deleted member 22229]

Yes that antenna is for the 2.4 Ghz band only if you wanted to use that on your 87 you would need to keep the 5 Ghz band disabled or it could cause damage to the 5 Ghz radio. They do make similar antennas that cover both bands.

Keep in mind there have been many posts of people trying different antennas some report some success but most dont see i huge difference in fact some report the stock antennas work better. As always YMMV...

 

[Big_AL]

Hey Kal-El,

I have the same router as Veldkornet - the RT-AC87U. I have the stock antennae. I have tried to find the dBi rating but can't find this info. Is it 5dBi ? Anyway - I ordered these yesterday to see if I get any improvement in signal at the far end of my house ( I don't want to add a repeater just yet as I hate the idea of more SSID's than necessary) http://www.amazon.co.uk/gp/product/B00L83EYUA/?tag=smallncom-21
4 x 9dBi 2.4GHz 5GHz Dual Band WiFi RP-SMA Antenna

I am not willing ( yet) to try any 3rd party FW to boost the TX power....as I really enjoy the current 'stock' ASUS FW. In a house with 3 teen age kids, I need something simple I can use on the fly to set time limits.....etc and the peace of mind of the filters and baked in anti virus and malware...etc.

So I am hoping these slightly larger antennae will raise the bar slightly, enough for a reasonable signal in the 'slow lane' part of my house. So these antennae are probably on the old slow boat from China as Amazon tells me I will only get them next month :-(

So I also noticed that you mentioned that if you connect a 2.4Ghz antenna only - you need to disable the 5Ghz function in the router...or it would damage the radio. I am just curious as to how and why this would happen, for my own understanding and education. So - what would happen if you disconnected only one of the antenna? Do all the antennae on the RT-AC87U transmit both bands simultaneously?

Sorry for all the questions. Enquiring minds want to know!

Cheers

 

[Deleted member 22229]

You want have anything to worry about the antannas you bought are duel band so no issues there. Just simply replace all four and give it a try. Good Luck !

 

[Big_AL]

Thanks very much - I will give it a go..

 

[Veldkornet]

Hmm, interested to see what the results are, let us know!


Sent from my iPhone using Tapatalk

 

[Haggster]

After seeing the reviews under that Amazon link I wouldn't be too optimistic...

And the description contains a laundry list of seemingly compatible routers but the RT-AC87 isn't even among them.

 

[dlandiss]

So I am hoping these slightly larger antennae will raise the bar slightly, enough for a reasonable signal in the 'slow lane' part of my house.

Remember that those antennas do not create more power -- they redirect the existing power in specific directions, much like the parabolic reflector behind a flashlight bulb. Assuming the antennas are vertical, the horizontal direction is the strongest like the attached "doughnut" image.

Higher-gain antennas that are still vertical sticks "flatten" the doughnut, resulting in stronger signals at right angles to the antenna orientation but less one floor up or down in your house.

 

[sfx2000]

Also should note that higher gain antennas increase the receive side, and they're not selective - so the relative receive level of the client against background noise is not changed...

They can actually increase the receive level enough that adjacent networks will now interfere with the local AP, whereas they would be just back of the background noise... thus hurting performance rather than helping.

 

[dlandiss]

Also should note that higher gain antennas increase the receive side, and they're not selective - so the relative receive level of the client against background noise is not changed...

That would depend on whether the limiting factor is "external noise" (radio intereference) or "internal noise" (thermal noise, shot noise).

Gain antennas obviously can do nothing about interference unless one is able to take advantage of their directivity to place the offender in a pattern null.

If the limit is internal noise the antennas help tremendously, because they provide gain before the first stage of amplification in the receiver. And the thermal noise over a 40MHz bandwidth can be considerable...........

 

[Big_AL]

After seeing the reviews under that Amazon link I wouldn't be too optimistic...

And the description contains a laundry list of seemingly compatible routers but the RT-AC87 isn't even among them.

Yes - I agree - I did see that too....the RT-AC87 doesn't appear on their list. There are 12dBi versions of seemingly the same 'brand' available.....but they are stupidly long and butt ugly. I think I would just about get away with the 9dBi ones I have ordered....as I mounted my RT-AC87 in the hall way ( roughly middle of my 125 year old Victorian double storey house) . Quite a negotiation with the Mrs!!

Anyway - I can return the 9dBi ones if there's no difference in performance.....no harm done.

Just as an alternative .....what 3rd party FW is available that will allow one to boost the TX power over the '100%' it's tied to...on the stock FW?

I suppose then, the trade off is that I would lose all the slick 'idiot proof' noob friendly UI....more importantly the baked in AV and anti malware and parental time limits and filters?

 

[Big_AL]

Remember that those antennas do not create more power -- they redirect the existing power in specific directions, much like the parabolic reflector behind a flashlight bulb. Assuming the antennas are vertical, the horizontal direction is the strongest like the attached "doughnut" image.

Higher-gain antennas that are still vertical sticks "flatten" the doughnut, resulting in stronger signals at right angles to the antenna orientation but less one floor up or down in your house.

Excellent information, thank you. So ...what you are saying is that a higher gain antenna has the effect of squashing the 'inner tube', meaning it will be thinner (top to bottom).....but the circumference....and therefore the reach, will be larger?

Thought you might find this interesting. It's an app that's due out in January I believe on IOS and Android I think.

I am sure this will revolutionise trouble shooting and remove some of the voodoo associated with wireless networks!

 

[dlandiss]

So ...what you are saying is that a higher gain antenna has the effect of squashing the 'inner tube', meaning it will be thinner (top to bottom).....but the circumference....and therefore the reach, will be larger?

Exactly.

Now somebody will jump in here and remind us that these patterns are theoretical only, and represent the antenna's behavior in free (non-reflective) space. He will be right--they are not this perfect. However, the theory, while modified in real usage, does give us a good starting point AND the reminder that power is not gained or lost--just redistributed.

 

[L&LD]

Excellent information, thank you. So ...what you are saying is that a higher gain antenna has the effect of squashing the 'inner tube', meaning it will be thinner (top to bottom).....but the circumference....and therefore the reach, will be larger?

Thought you might find this interesting. It's an app that's due out in January I believe on IOS and Android I think.

I am sure this will revolutionise trouble shooting and remove some of the voodoo associated with wireless networks!

Wow, the most uninformative video ever.

This will not revolutionize anything. Just as big of a waste of time as using utilities like inssider to optimize a network.

 

[dlandiss]

Just as big of a waste of time as using utilities like inssider to optimize a network.

Could you elaborate on why you feel that utilities like inSSIDer are a waste of time? We have found it to be quite helpful in finding "sweet spots" for access points, and choosing channels that minimize same-channel and adjacent-channel interference.

It also helped me identify a signal transmitting on the same channel as my access point and having similar strength. It was a Roku 3 streaming device trying to hook up with that access point even though the Roku was configured for a wired connection only. Once I found the way to move the unwanted Roku radio to another channel performance of the access point improved.

 

[L&LD]

Could you elaborate on why you feel that utilities like inSSIDer are a waste of time? We have found it to be quite helpful in finding "sweet spots" for access points, and choosing channels that minimize same-channel and adjacent-channel interference.

It also helped me identify a signal transmitting on the same channel as my access point and having similar strength. It was a Roku 3 streaming device trying to hook up with that access point even though the Roku was configured for a wired connection only. Once I found the way to move the unwanted Roku radio to another channel performance of the access point improved.

Inssider only shows number of networks and relative signals (which mean nothing for the actual signal reaching a specific device). It does not show network utilization, other (non-WiFi) sources of interference nor can it show latency improvements for different channels for clients either.

When I'm optimizing a wireless network for customers, actually selecting each channel available and testing for throughput, latency and range (multiple locations) from a wired NAS or other high performance storage server to a wireless client (laptop), collecting inssider information not only slows down the process, it actually interferes with it (when inssider was running, the real world throughput, latency and range was affected). In addition, it also confused the issue of which the best channel actually was. Often indicating that a certain channel was by far the best one to use when in actual use, the throughput was choppy, the latency was high and the range (although technically connected), was unusable.

On the other hand; the real world testing did not give any such discrepancies or conflicting data.

The best channel is simply the one that gives the best balance of throughput, low latency and range, period.

That method is fool proof because it takes the entire environment's variables into account (and not just what inssider decides (or is capable of) reporting).

 

[dlandiss]

collecting inssider information not only slows down the process, it actually interferes with it (when inssider was running, the real world throughput, latency and range was affected).

Kind of has to, doesn't it? The client WiFi adapter cannot devote all of its time to regular network traffic if it is also called upon to scan all of the channels and report their SSIDs, MAC addresses, and RSSIs.

As with most test equipment a skilled operator still has to interpret the readings and the conditions under which they were made. Various networks analyzers, both wired and wireless, have saved us countless hours despite their limitations.

 

[L&LD]

Kind of has to, doesn't it? The client WiFi adapter cannot devote all of its time to regular network traffic if it is also called upon to scan all of the channels and report their SSIDs, MAC addresses, and RSSIs.

As with most test equipment a skilled operator still has to interpret the readings and the conditions under which they were made. Various networks analyzers, both wired and wireless, have saved us countless hours despite their limitations.

You kind of missed the point that even using it in a 'skillful fashion', the data collected and the recommended actions were not lining up to real world use. This was on top of the time taken to needlessly record the signal strength, relative position of the ssid in question and then also manually analyze and test the indicated 'best' result as shown by a simple utility that is more toy than tool.

 

[dlandiss]

You kind of missed the point that even using it in a 'skillful fashion', the data collected and the recommended actions were not lining up to real world use.

Your point may have differed from mine. We do not perform detailed analysis of every location. If we have poor "real world" performance at any given client location, we use one or more of the utilities to tell us if it is a signal strength issue or if we need to look deeper. We don't use Metageek's recommendations, but look at the graphs to tell us what might be a more favorable channel, or if an access point will be needed to increase RSSI.

It doesn't work for you. It works for us--in the real world. No point in discussing it further.

 

[sfx2000]

Inssider only shows number of networks and relative signals (which mean nothing for the actual signal reaching a specific device). It does not show network utilization, other (non-WiFi) sources of interference nor can it show latency improvements for different channels for clients either.

InSSIDer (and many like this tool) only shows adjacent AP's that are not hidden - a cloaked SSID doesn't show there, nor does it reflect any clients attached to a given AP. It's also very dependent on the feedback/info provided by the Windows driver, so some are good, some not so good..

Not saying that it's a bad tool, it's good, but there are other tools that pro's like L&LD and others use as part of our role as wireless consultants/engineers/developers..