iMac Wi-Fi intermittent connection

How is it dropping out? Are you doing ping tests and finding dropped packets or is it loosing connection completely?

First one, mavericks runs some funny power saving features which cuts power to wifi frequently unless it's requesting a stream of data. Pings aren't enough to wake it up to full power. It gives the illusion of packet loss when in fact there is none.

If wifi is dropping as in disconnecting then it is likely to be wifi interface. Not great if your previous computer in the same place was fine.

I have issues with weak signal too and live in a super congested wifi area. I solved my problems with poor signal by repositioning the antennas if you have them or laying the box on its side, not on the vents tho! But the main change that worked was changing the wifi channel. Try 1, 6, or 11 and try using inSSIDer to check channel congestion for the best channel.

 

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Could you press the option key and click on the wifi icon once connected to see what speed you are achieving.

It should tell you the transmit rate and signal values

 

Your transmit rate and signal is quite good. The new channel should potentially rule out interference unless it's very congested.

The only other thing I can think of is if you have another wifi access point you can try connecting to. Connect it to the router via Ethernet and set is as an access point mode and make sure the dhcp is disabled on the wifi box.

Falling that it's a hardware return I think

Only time I ever had a wifi drop out was when my MBA failed to reconnect from sleep because it was on channel 13. If the imac is going grey and loosing the connection either the router is loosing signal or power or the hardware in the imac is failing.

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Ps : check your router doesn't have power saving enabled on the wifi. If possible reset the router but only do so once you have all the access codes etc you need to set if back up again to your needs

 

Do you have any other wireless equipment in your house? Like phone, baby monitor, keyboard, mouse (especially another brand then Apple's). Our wireless went down every time my girlfriend startup her PC with Logitec wireless mouse and keyboard. Apparently they all work on the 2,4 GHZ band and caused major interference. It took me a while that it was her wireless mouse and keyboard that caused it. Replaced them with my old USB Apple mouse and keyboard and now have a solid connection again!

 

I'm guessing but those should all be ok. We have similar wifi equipment in our house. But as the other poster said baby monitors and other devices like cordless phones do mess with the wifi signal.

You can change the 2.4ghz to 5ghz which is usually much less congested. In my house I can see upwards of 12 wifi networks on 2.4ghz but I see no 5ghz.

Trying to skype on 2.4ghz is pointless, on 5ghz I have no issues. To get 5ghz you need a compatible router / wifi access point and 5ghz needs to be available. You just simply turn it on and connect to the ssid name you assigned to the 5ghz network.

Few things tho, if your router can even do 5ghz some of your devices might not have 5ghz capability. Therefore you would need to run 2 networks, some access points like the latest airport express / extremes allow you to run dual band networks at the same time... As do other decent routers.

If you don't have 5ghz I could only guess you need to isolate by switching everything else off. Only problem is if next door have these phones or baby monitors.

 

What model iMac is this? I recently picked up a late-2013 model which exhibited all kinds of wifi connectivity issues (completely dropping the connection every 1-2 hours).

If you have this model as well I think it could either be hardware/firmware related or something with Mavericks and this particular chipset. Some people have said it's the same or similar to the issue some experience with the MBA.

My network strength was never an issue, and I could do nothing to get the dropped connections every hour or two to stop. Previous iMac has no issues. No laptops or mobile devices in the house had any issues either other than the iMac. No interference in the area.

 

It's not that clear the iMac is the problem.

There can be a gigantic difference between different routers, in terms of performance -- in concurrent data handling and radio frequency performance (range, reliability, etc)

Typically an ISP will install the cheapest router they can. It may have limited data handling, limited features and limited RF performance.

Upgrading to a higher performance router will often help. I like Asus routers, several of which have user-adjustable RF power output.

Your 2012 iMac supports 802.11n MIMO (Multiple Input Multiple Output) which uses several antennas in parallel to improve performance. Ideally you'd want a multiple-antenna router which supports that. One example is the Asus RT-N66U, about $120: http://www.asus.com/Networking/RTN66U/

I have an RT-AC66R:http://www.asus.com/us/Networking/RTAC66R My 2013 iMac 27 uses only wireless internet, and I typically get 120 megabit/sec down, 20 megabit/sec up.

Other brands of routers are also good, I'm just familiar with Asus.

There's an iOS app called Network MultiMeter that helps isolate WiFi performance problems: https://itunes.apple.com/app/id518835474

 

I fixed my poor signal by buying myself a set of TP LINK home plugs. Uses your houses electrics as an ethernet cable. Check them out:

http://www.amazon.co.uk/gp/aw/d/B004INVKP4