Wireless speed issues on the 2.4ghz band

[Pierino]

I have had this router for about 4 months now and I am starting to notice my wireless speed seems to fluctuate wildly. I am on RMerlin's 220.18b fw now but have tried ASUS official fw with the same result.
I pay for 30mb down and 3mb up but just now I got less than 1mb down.
I am not on auto channel, I used inssidr and am using ch11 which is unused around me. I am also using only 20mhz bandwidth.
Any advice?
The 5ghz runs fine.

 

[RMerlin]

I have had this router for about 4 months now and I am starting to notice my wireless speed seems to fluctuate wildly. I am on RMerlin's 220.18b fw now but have tried ASUS official fw with the same result.
I pay for 30mb down and 3mb up but just now I got less than 1mb down.
I am not on auto channel, I used inssidr and am using ch11 which is unused around me. I am also using only 20mhz bandwidth.
Any advice?
The 5ghz runs fine.

Disable QoS, and test LAN to LAN to make sure it's not a WAN-specific issue.

 

[Pierino]

Qos has always been disabled and only wireless is effected.
Right now I have a wrt54gsv7 hooked up and it's working better than the n66u on the same settings.
I think it's time to return it.
Thanks RMerlin.

 

[Starrbuck]

Are you sure channel 11 is unused? Try other channels just to be sure. Some may work better than others.

 

[Pierino]

I'm positive ch11 is unused, I've tried others as well. Right now I'm getting 11mbs down with my old wrt54gs.
Maybe the rt-n66u is going bad. Anyway, I am going to try another one or maybe the ac66u.

 

[Pierino]

Exchanged my n66u for another one and speeds are back to normal on the same settings. Fw2 20.18b.
Kind of scary that the router started to fail after 5 months. I also noticed that the new router is about 5-6 degrees Celsius cooler.

 

[SoCalReviews]

It sounds like the 2.4Ghz radio went bad on the previous router. It's great to hear you were able to promptly replace it. I currently have three RT-N66Us in operation. I purchased the first one more than three months ago in July. Right now all three are running perfectly with moderate to heavy usage for two of them. I am currently using the latest Asus 4.220 firmware. I am hoping all three continue to perform well. Fortunately I have never had a wireless router that I owned go bad. The only thing I am always weary about on all these kinds of devices are the AC power supply adapters (especially the lighter switching power supply adapters that are used for most of today's electronics). They are often the weak link in the production quality control for electronics and it always seems to be difficult to obtain the right one when you need it. I am a big advocate of redundancy solutions and spare parts for my essential computer and networking products. Having back up parts has saved me countless times in the past including recently when I had access to an exact AC adapter used for specific business fax/scanner. When they are back in stock on the Asus parts site I might pick up a spare 19v, 30W, AC power supply adapter for my RT-N66Us to have for the future just in case.