Fibre wireless -poor speeds

[#1]

I had Fibre Extra installed at my property last week. I am getting good speed when connected via ethernet, around 74mbps. But when i go wireless (but sitting next to the router Plusnet 2704n) i am getting only 27mbps.
I thought it could be a channel issue and looked at what wireless channels were currently most in use around my property. The results via WifiInfoView showed channel 6 and 11.
I logged into the router and it shows that my channel is set to auto, on wifiinfoview is says channel 1.
I decided to check each channel while sitting next to my router, I changed over to each channel and completed 3 speedtests, after making sure via wifiinfoview that my channel had changed over. These are the highest results per channel, but from the 3 speedtests, the speeds were very different, and were not consistent. But these are the highest speeds achieved .
Channel 1: 27mbps
Channel 2: 30mbps
Channel 3: 19mbps
Channel 4: 19mbps
Channel 5: 21mbps
Channel 6: did not use
Channel 7: 27mbps
Channel 8: 33mbps
Channel 9: 15mbps
Channel 10: 25mbps
Channel 11: did not use
Channel 12: 30mbps
Channel 13: 13mbps
How comes the speed is so poor via wireless connection? This is the speed when being 1 meter away from the router, the speed is much less when i am further away.

[#2]

It might be worth you reading up on Wireless, this one from PCAdvisor should help.
Looking at your results it would appear there may be a lot of interference from other routers in your area, plus you are not using the higher 5Ghz channels.

[#3]

The plusnet router does not use 5Ghz  also it has very poor wireless range and capabilities it wont make much difference what the OP does, only way to get better wi-fi is to purchase a better router or try homeplugs

[#4]

You should have tried channels 6 and 11. In theory, it's better to be on the same channel as other networks, than to be on a channel that partly overlaps other channels. Using channels 1, 6 and 11 results in no overlaps, which is why most routers, when set to pick a channel automatically, will choose one of those. Being on the same channel as other networks will not necessarily cause any problems.
Also, a better wireless router won't really help if your wireless adapter is only 11g or 150 Mbps 11n. 20 to 30 Mbps download speeds would be around the maximum possible over 11g wireless.
Interference could be from anything that uses the same frequency range as the wireless, such as bluetooth, or other sources of interference like poorly shielded USB3 devices or cables.

[#5]

Have you ever seen faster speeds on the PC you are using when connected wirelessly to another network?

[#6]

Thanks for the replies. I've had a look at the link.
I have expereinced around 70mbps when connected to friends network, so i know my laptop is capable of receiving higher speeds. So in theory the router (2704n) provided by plusnet is an 802.11bgn router. Looking at the link provided, i would need a 802.11ac like AVM Fritz!Box 3490?
But then i am confused with the post regarding my wireless adapter... What's my wireless adapter?

[#7]

The wireless network adapter is the piece of hardware that does the wireless, inside the laptop. Can you find out the specification of the laptop's wireless?
In the past, Plusnet have demonstrated it was possible to get 70Mbps download speeds with the previous model of router they supplied, and the 2704n should have the same or slightly better wireless than that.

[#8]

Someone with more knowledge about the 2704n may explain more, but it seems it does not use the higher speed 5Ghz channels, only 1-13. It does however seem to use 4 channels in order to get the higher throughput, that said the router default is for 144Mbps, so changing it to 300Mbps may help.
As for the question about the ac router, you will always be limited by the slowest part of your network, so it would be worth finding the spec of you Laptop Wi-Fi adapter.
You may have got the higher throughput at your friends house if their router used the 5Ghz channels.