2.1 GHz Antennas for 3G. Virgin Broadband, the '3' network and Optus.
2.1GHz is starting to become an important frequency for 3G and Virgin Broadband. And the '3' network.
Questions and Answers
Q Can an antenna give me a better connection for VBB?
A. If you are getting a hint of UMTS or HSDPA then, probably, yes. Just look at the display panel of your VBB modem. If you can only get GPRS then it's not looking too good. Even with a good GPRS (900MHz) signal you won't get a very fast connection, maybe just slightly faster than dial-up speed. The VBB connection speed you can expect with a good signal on UMTS/HSDPA (2.1GHz) is about 700kbps or around 14 x dial up speed. . You may need to do some tests on your roof with the modem to check for evidence of UMTS/HSDPA. We've just heard of an injury to one of our customers, falling from a roof, so please take care and use the proper safety equipment! :-)
The antennas below are for UMTS/HSDPA (2.1GHz) only. If you wish to improve your GPRS (900MHz) reception and are happy with the slower speed, please email us. See also the comments on using VBB in wet weather below.
Two bars on the signal strength meter ( -90dBm) should give you reasonably solid connection. Try to get a reading in dBm rather than just looking at the number of bars. If you look through whirlpool posts you'll see what people are typically getting. http://forums.whirlpool.net.au/forum-replies.cfm?t=799422
Try turning off GPRS: http://www.zdnet.com.au/blogs/securifythis/soa/Kill-GPRS-to-make-Virgin-Broadband-fly/0,139033343,339281471,00.htm
Q. Which antenna should I choose?
A. We have a range of grid antennas which are designed for this frequency (2.1GHz). The two smaller sizes will fit on to the type of J pole commonly used with TV antennas, even with a TV antenna fitted also. The two frequencies are quite different and no interference should occur. Available from Bunnings or a TV antenna supplier such as Hills or (pick up only) from RFShop. Also these can fit on to solid ventilation pipes or balcony rails.. The larger size, 87cm x 66cm, will still fit on to this pole but due to its addition weight additional guy lines may be needed. As far as we know, the setup should be for Vertical polarisation. See ASSEMBLY INSTRUCTIONS . The RFS_6040_2.1 is the one we normally recommend.
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RFS_6040_2.1 $90 ex-GST
Size is 60 x 40 cm
You will also need:
1) an extension lead
N30FME80-JBY195-700 700mm $17
N30FME80-JBY195-2000 2mtrs $20
N30FME80-JBY195-3000 3 mtrs $22
N30FME80-JBY195-4000 4 mtrs $24
N30FME80-JBY195-5000 5 mtrs $25
N30FME80-JBY195-7000 7 mtrs $27
N30FME80-JBY195-10000 10 mtrs $30
or can make up length to order. Please email
order with delivery address (so we can calculate freight)
if requiring special length cable or if you are having
a problem with the shopping cart.
2) Pigtails adaptor to Virgin Mobile
FME30MC39 $22
Prices ex-GST
Or, if you are wanting to fit a wall plate, see
question below on wall plates and special cable assemblies. |
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RFS_3629_2.1 $75 ex-GST
Size is 36 x 29 cm
You'll also need cabling items as above. |
In addition we have tested out some smaller panel antennas.
Panel Antenna for 2.1GHz 3G band. SPL-1900-2300
These will also fit either on a wall, or on to a pole, In general, the higher the gain, the more carefully you need to point them and the stronger the required mountings.
Getting a good signal from VBB is very much like getting a good signal for your TV. If you live in a weak signal area you'll need a decent sized antenna on your roof. If you just need a slight improvement then a small panel antenna should be enough.
Q. Can I have the cable terminated on a wall plate to make it look neater?
A. Yes. We can also supply customised cables, such as this one with a bulkhead connector and wall panel:
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N male to N female (bulkhead fitting cable)
N30N85-JBY195-5000 5 mtrs $30
N30N85-JBY195-7000 7 mtrs $32
N30N85-JBY195-10000 10 mtrs $35
You'll also need a
N30MC39-RG316-300 300mm $18
or
N30MC39-LMR100-1500 1.5mtrs $22
Drilled Wallplate WPlate1 $8
Prices ex-GST
or we can make up length to order. Please email order with delivery address (so we can calculate freight)
if requiring special length cable or if you are having a problem with the shopping cart. |
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If you need very long lengths of cable you may wish to specify LMR400 CABLE ASSEMBLIES for minimum loss. About 1/3 of the loss of LMR195. This relatively expensive and more bulky so its a good idea, if you want to use 15 metres of LMR400 to check out your system with 5 metres of LMR195 first. We can quote on bulkhead fitting LMR400 cable.
You'll need to email us at (rfshop@gmail.com) or any of the "rfshop.com.au" addresses for customised products. They won't be on the shopping cart.
Q. What about the length of the cables?
Try to keep them as short as you can. The signals are at 2.1 GHz (2100MHZ) so do not travel down cable as easily as TV signals which are at approximately 1/10th of the frequency. We use LMR195 cable as standard. This has a relatively low loss. 10 metres is usually OK. 5 metres is better.
Consider moving your modem closer to your antenna and run ethernet RJ45 CABLE ASSEMBLIES to your computer and phone cable to your phone.
Q. Do I need pigatil adaptors to the modem ?
Yes. http://www.rfshop.com.au/Default.aspx?tabid=426&txtSearch=FME30MC39&List=1
Virgin BB desktop Globesurfer 2 modems have MC connectors.
E160 and E169 modems have a proprietary connector. Please quote the model number of your modem if you are using these.
Please email us a picture or quote the model number of your modem if you are not sure.
Q. What if I can't get an improvement?
A. Plug the pigtail into the modem with nothing else connected. You should see the signal drop down to zero. This tests out the modem's internal switch. Then when you do connect the antenna to the pigtail you should get a signal and you will know that the signal you are measuring comes from the external and not the internal antenna.
You will also have to experiment with the direction that you point the antenna. The polarisation should be vertical but it may be worthwhile rotating the antenna to test this.
Try to avoid running on GPRS. Even with a good signal the internet speed will be poor.
Q . How do I make an order?
A. You need three things.
1) An antenna of your choice.
2) A Pigtail adaptor.
3) An Extension Lead http://www.rfshop.com.au/Default.aspx?tabid=426&txtSearch=N30FME80&List=1
The shopping cart shows lead lengths up to 10 metres. Just email us if you need anything longer.
Either order through the shopping cart or send us an email if you aren't sure and we'll check it all makes sense.
Q. What's the cheapest option?
A. You can build build your own cantenna :
http://www.rfshop.com.au/Default.aspx?tabid=426&txtSearch=0210A&List=1
with pigtail lead
http://www.rfshop.com.au/Default.aspx?tabid=426&txtSearch=N30MC39&List=1
for about $32 including the patch lead. Express Postage is about $8.80
It doesn't look the most hi-tech piece of equipment but it works surprisingly well :-)
You can also use this cantenna to increase the range of your home wireless (2.45Ghz) network or the '3' network. You'll probably need different pigtails though.
Q Can you do installations?
A. We may be able to help. Either contact us or:
Brisbane
Ian Pollock
Carina
0435135315
ianp@highsun.com.au
If you can offer this service in other areas. Pls just let us know and we can add your details. We'd be happy to suppy you with antennas etc in addition to customer leads.
Q. My VBB connection is OK when its dry but falls over in the wet.
A. During wet weather the UMTS /HSDPA (2.1GHz) signal, especially if it has to pass through wet trees, may fade and you may be better switching back, temporarily, to GPRS (900 MHz) with a different indoor antenna which has to be for 900MHz, of course, not the grid or panel antenna for 2.1GHz. Don't unplug the MC connector to the modem too often. Eventually it will break. Instead connect the same pigtail to an antenna similar to this:
http://www.rfshop.com.au/Default.aspx?tabid=426&txtSearch=tc1306&List=1
Q Can I just put the modem up on the roof without using an external antenna?
A Yes. You can put it in a weatherproof box in the same way that we recommend for "Unwired" users. See
UNWIRED BLOG
The disadvantage of this method is that you may find it harder to make a wireless connection between the modem and your PC. Also, the signal strength may still need boosting with a larger antenna. One advantage is that the cable loss is minimised and a combination of this method and a large antenna would be the way to go when you were really struggling to get a good signal.
Q. I have connected the antenna and it doesn't seem to make any difference. What can I do?
We have heard this comment from time to time. Try this procedure:
1) Just connect the small pigtail adaptor to the modem. Nothing else. No antenna or extra cable.
Make sure it pushes fully in.
2) Check to see if the signal has gone to down to zero. There should be a switch in the modem which switches over from the internal antenna to the external antenna. If it the signal level has not dropped a lot it is an indication that this switch is faulty.
3) Now when you connect the external antenna you know that any signal you do see is coming through the external antenna. The antennas are directional and for UMTS/HSDPA only so disregard any previous GPRS
If there is anyone from VBB reading this who understands the issues when using an external antenna I'd appreciate it if you could give RFShop a call to discuss these points. We are happy that Virgin do refer their customers to us but we would appreciate it if they'd actually talk to us as well, about what is and is not possible !
Q. What is the cost of freight
A. Freight will depend on the size of the antenna and location but it'll be around $10 for a panel antenna + cables , $12 -$15 for a medium sized grid, $18 for a large grid to Sydney and Melbourne. The total cost for a medium grid (+ cables & pigtail) is going to be around $165 including GST and freight.
This link may be useful to help you locate a tower transmitting on 2.1GHz
http://web.acma.gov.au:80/pls/radcom/register_search.main_page
But, probably you'll need to try it and see. If you are even getting a hint of UMTS or HSDPA reception without an external antenna then things are looking promising.
Q. What if I can't get VBB even with an external antenna?
There are several other possibilities.
In Adelaide: these guys are very good. www.nuskope.com.au
On the North NSW coast/Gold Coast Area there is www.wwwires.com
Please let us know if you'd like a free link to your community wireless network included here.
Then there is www.iBurst.com.au , www.unwired.com.au, www.nextg.com.au
We can supply antennas for all of these. See our FAQ section.
Pics of an Installation 
