Archive for July, 2011

Long Range Wireless Wifi Signal Problems

July 20, 2011

One of the perennial problems of Wireless Wifi is achieving good signal at longer  range or in situations where there are obstructions such as walls , buildings and trees.  A belief has developed among consumers that high rf output is the solution to this problem and this has produced a number of Wifi devices which have high power and offer long range. Among the very best of these longer range devices is the Alfa Networks AWUS036h USB adaptor. The latest version is rated at 1000mw and there is no doubt that it outperforms built in laptop Wifi.

A couple of days ago I had a few minutes to spare and decided to make a simple test using a laptop, Alfa AWUS036H and a new outdoor USB Wifi Adaptor. From the same outdoor position each device was tried in turn and a measure was taken of how many Access  Points were detected. This trial was carried out quite high on the side of a mountain valley in Andorra. There were lots of flats and houses on the far side of the valley and some nearby on the same side of the valley. Across the valley conditions were ideal for long range – good clear line of sight.


Device                Laptop Wifi  Alfa 036H   Outdoor USB device

No.  of APs              18                      127                       138

These are interesting results with the Alfa 036H showing a massive increase in APs detected over the built in laptop wifi.

Alfa AWUS036H. This is the 500mw versions with 2dBi detachable antenna. I used the 1000mw unit which is identical but has a 5dBi antenna to give the rated output.

The outdoor usb wifi adaptor was also good. Here is a photograph of the outdoor unit. This comes with a high gain antenna – 8dBi and  5 metre USB cable. The long USB cable allows for positioning of the unit for best signal.

The Alfa 036H is the obvious choice for indoors and dry days outdoors. It is small, lightweight and the performance is good. The outdoor unit  offers better range and signal ( more APs detected) but is bulky. As with the Alfa 036H it is very easy to set up and use and offers good possibilities for yachts, boats, garden offices, campervans etc where portability is not a big consideration but the extra range and signal would be useful.


Next day I repeated the tests in a supermarket carpark. This was in an urban situation with buildings all round so less than ideal for long range. I tried each device in turn on the dashboard of my van. Here are the results –


Device                Laptop Wifi  Alfa 036H   Outdoor USB device

No.  of APs              7                     16                         29

Clear gain in number of APs detected with the Alfa 036H and big gain with the Outdoor USB device.

September 2012

Outdoor wifi adaptor with Alfa R36 Router is giving a good long range connection to a local wifi hotspot. The hotspot is about 200 metres away and not in view. This set up – Outdoor Wifi Adaptor with Alfa R36 – just needs a power supply to give good long range wifi connection which can be used locally by several wifi enabled devices. Good set up for boat, caravan or campervan, shed or garden office! Free internet all day with the connection managed by the R36.

More details of the Outdoor Wifi Adaptor here –

And R36 router here –


Interesting Railway Story – Cerbere, France

July 17, 2011

Cerbere is in France a couple of miles from the Spanish border. The railways in France and Spain have different track gauges. Cerbere thrived for many years on unloading goods from a French train and reloading onto a Spanish train. Now the trains stay loaded and the axles are changed for the journey over the border.

In France there is hope.

Nice item in the Telegraph  May 2012 – see link Cerebere