The working end of one of my experimental 2.2GHz
Yagi aerials made of 2mm brass rod, cable ties and glue!
You will notice that I do not sell any parts on these pages, the whole idea is to save money not spend it! However I do realise that some people will want to buy things to boost their 3G broadband. So this page is to suggest that you be careful what you buy. Some of the items sold on places like eBay are worse than useless and are sold at astounding prices, probably based on the idea that the more people pay the batter they will think the item is! Some items however work well and can be almost as cheap as making it yourself. The Yagi aerials sold by ChinaRF for £15 do work, and work very well. I recommend you look at their web site on eBay http://myworld.ebay.co.uk/chinarf/ Their Wi-Fi booster aerial (about £13) also works well giving a range of many hundreds of metres point to point - provided you use an aerial at each end! So you could send your Wi-Fi all over your farm or to a remote farm cottage or whatever saving a lot of money, but some other items sold do not represent such good value! Email me if you want help, but please remember that I am not a business and may be unable to reply immediately.
These are pictures of the "works" of an external aerial that is sold by many places on the internet. The one shown here was purchased (not by me I hasten to add) at the astounding price of £45! It was given to me to take apart and "repair" as the buyer said his signal was better without it! Looking inside you can see that the parts to make this aerial probably cost £2 trade so you can see that the manufacturer and retailer both made a handsome profit on this particular sale! Exactly, precisely the same thing can be bought elsewhere on the internet for £7, so LOOK AROUND before opening your wallet. Even £7 is £7 too much in my opinion though as this design works very poorly indeed, possibly because they used the wrong type and wrong thickness of printed circuit board. You would get the same increase in signal by putting your dongle beside the window on a long USB cable bought from a 99p shop. Better still use my "coat hanger" design now on Page 2 of this site which should not cost more than £1 to make including the wire and plug. Some items are advertised by people who have no idea whatsoever what they are selling and who blindly copy any descriptions or writeups that they can find on the internet. Some do it by mistake, others couldn't care less that they are misleading you.
The aerial shown above is widely advertised as having a 12dB gain. In other words it should boost the signals both to and from the 3G base station by at least 4 times. The one given to me doesn't! In fact a look inside indicates that it is not possible to get this much amplification from this design. They have even left out a vital part that makes the aerial "talk" to the cable properly. This "balun" as it is called is essential ( you can see one on my aerial at the top of the page, it's the extra loop of wire) but they have not bothered to include one on the £45 model! I put one on to see if it helped but it only made a slight increase, still nowhere near the advertised 12dB boost. This is probably why the manufacturer did not bother to fit it!
The next warning concerns the use of Wi-Fi aerials, boosters etc. Some people think (and some sellers are happy to encourage the idea) that a Wi-Fi aerial will work on a 3G dongle. It will not! Never, no way! The reason is wavelength. All aerials have to be made to work at or near a certain wavelength. That's everything from TV aerials to short wave radio transmitters. Wi-Fi works at a different frequency to 3G dongles so there is little chance of one made for one system helping on a different frequency. Think of it as using a TV aerial to boost your radio reception. It might help a bit but certainly not as it should. Save your money!
p.s. If you have a Wi-Fi aerial that is not being used for anything else then you can try plugging it into your dongle as the wire might help a bit and give you a slight power boost, but please don't waste money and buy one specially! Wi-Fi Yagi booster aerials do work well though for Wi-Fi extension, but you really should have an aerial at each end of the link. That's a popular mistake expecting a single aerial at one end to give a huge boost in signal level. Using the right aerial, and right connection at each end can quite easily send a Wi-Fi signal over a mile or more, so it can be done!
August 22nd 2013 - this page still being written!