I purchased a simular antenna for mine but it didn't make much of a difference. This is the one I purchased:
http://cgi.ebay.ca/ws/eBayISAPI.dll?...m=390141182371
I have several towers around me and 2 of them are 850Mhz and 1900Mhz. The antenna only increases the signal by about 1. When I had my hub setup in the basement, I was getting a signal of about 2 to 3 but with the antenna, it would be 3 maybe 4. If I could get the antenna outside, I'm sure it would have been more but the magnetic mount is more for a car and the coax isn't really long enough to go any distance.
I found this site that talks about range of GSM celular towers. They say the maximum range is 35km
http://www.tomshardware.com/forum/33302-39-tower-range
I've seen external, directional antennas that have 40db or more gain but they are quite expensive. I've even seen them on Ebay. Don't know if one would work or not to reach the 3G tower.
I found a forum on the Rocket Hub (Ericsson W35) which may have some information. I've seen people posting about external antennas.
http://fwt.ericsson.net/viewforum.ph...2aae5365293fe9
One thing I just did was purchase a wireless Bridge for my Hub. That way, I can now have the Hub in my master bedroom where is gets 4 to 5 signal and run my computers in the basement wirelessly. The Bridge is a Print Server and allows me to print to one printer from any computer in the home Network. Tiger Direct had them on sale.
http://www.tigerdirect.ca/applicatio...4183&CatId=371
There were a few issues getting it to hold connection to my Hub but I've got it working now using another wireless router I have. I spent quite a bit of time on it but never did try differnet security setting. The Whitelist doesn't seem to work properly on the Hub but again, I haven't had much time to work on it.