Antenna replacements?

[mojothehut]

hey all
I was wondering if larger antenna replacements for my Linksys WRT1900AC router would extend the range in my house a little bit? Any drawbacks from replacing the default 3-ish inch antenna with these monsters?

http://www.newegg.com/Product/Produc...4691-_-Product

$16 why not? It doesn't exactly list my router as compatible but I don't see why it wouldn't screw in just fine.

 

[azazel1024]

Always possible they could create feedback in each other from the high gain, or other issues with reflection/multipath in your house depending on where it is located and what not.

Do not expect any real greater range. The WRT1900AC comes with 5dBi antennas IIRC, so 9dBi isn't really that much stronger (~2.5x higher signal strength). It should provide a modest boost to speed at current medium and long distance locations, but it probably won't actually push the signal to anywhere where you can't get it currently.

In my antenna experiments replacing the 3dBi antnennas on an Archer C8 with 5dBi saw around a 10-20% boost in 5GHz performance and 5-15% in 2.4GHz performance at various locations. One location where I could see the 5GHz network, but not connect I can now connect with a very slow connection. No extra perceivable range with 2.4GHz. Performance increase was generally more at longer distances with 2.4GHz, but I saw a boost on 5GHz even close in.

On my WDR3600 I replaced the 5dBi with 7dBi and I saw a 5-15% increase in 5GHz performance and 5-10% increase in 2.4GHz performance, but no increase in performance when close to router (unlike the C8, which saw 5GHz performance increase even close in, though not with 2.4GHz).

That is only a 2dBi bump and you are looking at probably a 4dBi bump. So...yeah, I'd expect you to see some performance improvements. However, path losses indoors are so high, don't expect to get a signal further away. you need a second access point for that. The signal loss just pushing through a regular wall is generally on the order of 3-5dBm for 2.4GHz and 4-8dBm for 5GHz, so a 4dBi gain is at most going to equate to a bog standard 2x4" wall (and not account for any extra distance, which is inverse square law, which means 6dBm loss in signal strength for every doubling of distance from the router).

PS as a note on my earlier bit, when I replaced the 5dBi with 7dBi antennas on my WDR3600, with its one location, I actually saw a performance loss in several locations and only mild gains in a couple. Relocating the access point to a new location and then retesting found the new location to be faster with the stock 5dBi antennas, but the 7dBi antennas ALSO increased performance in every single tested location over the 5dBi antennas then. I was probably getting weird reflections/mulitpath off the chimney/fireplace that the AP was located up against and the higher gain antennas magnified the problem, instead of simply getting a stronger signal to my clients.

 

[mojothehut]

Thanks for the useful information.
I'll play with the antenna, the price is so cheap why not. If I noticed worst performance like feedback or whatever, Ill switch back.

 

[JackMDS]

If money is Not an Issue, then it worth while to try.

Many of the (so call) Antennae put on consumers Wireless' devices are just a piece of wire.

Thus at times replacing the Antenna with a better made one can help regardless of being Highgain (or Not).

 

[mojothehut]

Posting a quick followup.

The new antennas seem to work just fine. The remote corner of my house where I previously only had about 2 bars of signal strength, I now have 4 to full

 

[EvaCarey]

If you are facing a antenna problem then replacing antenna is a best option, it is a cheap practical solution for replacing a antenna. Well I think information given by azazel is a best information for replacing the antenna.

 

[dave_the_nerd]

I recently did the same. It seemed to help a bit on the reception downstairs (opposite end of the house from the AP.)

But it's not night and day, and it might even be psychosomatic. I don't have a proper wifi spectrum analyzer, after all, just a utility on my laptop that showed me yellow bars, and showed longer green bars after I swapped antennae.

There's a practical limit to this, too. Ultimately, you can kick a signal out of your wifi router that'll peel paint, but if your laptop or whatever can't push an equivalent signal back to the router, it's pointless.

 

[smitbret]

In my antenna experiments replacing the 3dBi antnennas on an Archer C8 with 5dBi saw around a 10-20% boost in 5GHz performance and 5-15% in 2.4GHz performance at various locations. One location where I could see the 5GHz network, but not connect I can now connect with a very slow connection. No extra perceivable range with 2.4GHz. Performance increase was generally more at longer distances with 2.4GHz, but I saw a boost on 5GHz even close in.

On my WDR3600 I replaced the 5dBi with 7dBi and I saw a 5-15% increase in 5GHz performance and 5-10% increase in 2.4GHz performance, but no increase in performance when close to router (unlike the C8, which saw 5GHz performance increase even close in, though not with 2.4GHz).

Dang, I have some old antennas lying around from my old D-Link DI. I think I will swap 'em out on my Archer C7 and see what happens.

 

[azazel1024]

Keep in mind that the Archer C7 is external 5GHz antennas only, the 2.4Ghz antennas are internal and seperate. The Archer C8 has dual band externals.

 

[smitbret]

Keep in mind that the Archer C7 is external 5GHz antennas only, the 2.4Ghz antennas are internal and seperate. The Archer C8 has dual band externals.

Yeah, I just feed some of my mobile devices with the 5GHz bans and there is a corner of the house that is near a stairwell that juuuuust gets lost on 5GHz. I never really saw much benefit when I tried a couple of sets of non OEM antennas on my old D-Link so I never really gave it a second thought. It's just screw on/test/screw off if it doesn't work. The most time consuming part will be finding the antennae.

 

[John Connor]

I have larger antennas like this for my router I bought on eBay that came all the way from China. I bet it's just a piece of wire. Are these antennas different?

 

[azazel1024]

For an omni, there is a difference in quality and there CAN be a difference in the dipole size, etc, but they are basically all half dipole antennas. So a 5dBi omni is a 5dBi omni is a 5dBi omni WITHIN REASON. There can and will be slight difference between them depending on the exact size they use, resistance of the wire (should be 50 ohms), etc.

Otherwise they'll have extremely close to the same gain and same radiation pattern, supposing they are really the gain stated.

 

[John Connor]

I made a couple of these and the signal did go up in that direction. LOL

http://www.freeantennas.com/projects/template2/

 

[arkcom]

There's a practical limit to this, too. Ultimately, you can kick a signal out of your wifi router that'll peel paint, but if your laptop or whatever can't push an equivalent signal back to the router, it's pointless.

Antenna gain will increase reception to the router just like it does transmission.

 

[JackMDS]

Quality of Antenna has nothing to do with small or big size.

The size is a derivative of the wave length and putting Antenna that is longer than the needed kills/attenuate the signal.

What is important is the impedance (projected residence) of the Antenna to match the impedance of the RF output circuit of the Wireless device, and staying stable for the life of the Antenna.

Good Antenna is an Antenna that after it is manufactured each is tested and make sure that the impedance is correct, the physical design is so that it does not change its parameter in time, and that the connectors are fit and do not change their connectivity over time.

The Gain of an Antenna his a derivative of the Size of the transmission field, the narrower it is the more Gain is provided.

 

[billyb0b]

load 3rd party firmware and boost the tx power

 

[azazel1024]

load 3rd party firmware and boost the tx power

Often does little to nothing (though not always). 11n/ac are symetrical MCS rates. That means that you can't have higher receive than transmit rates (11n has optional asymetrical, but I don't know of any chipsets that implement it. 11ac dropped the option completely).

Get the Tx power too high and you are in a situation where you have hidden node issues/hidden clients. The base station is so loud that the client can still hear it, but the basestation can't hear the clients acknowledgements (and they have to come at a regular pace, otherwise the basestation holds transmissions and/or retransmits).

At best higher Tx power is a mild panecea that can slightly boost transmit bandwidth and medium to long range. It won't really increase maximum range, as you are limited by the clients Tx power. Only time it is highly beneficial is if you can boost BOTH the basestation and the client (IE with things like wireless bridges and stuff).

This is why most routers/APs typically only broadcast at 50-100mw where as most laptops and mobile clients are in the 25-32mw range, because unbalance the Tx power equation too much, and it doesn't provide any benefit at all (and actually it can lead to roaming issues as the client things the network connection is stronger than it truely is). Also the electronics of the radio are made with an "ideal" Tx power. Increase it too much and it leads to wave form distortion, which decreases throughput.

Increase Tx power is generally something to do with extreme caution and lots of testing. it CAN be beneficial in SOME circumstances, but it can actually be a negative in others.

Also keep in mind, you have to boost it a lot to get much dB gain (3dB is a doubling of power).