External high-gain aerial for mobile braodband dongle

[FadeToScarlet]

I was just wondering if anyone had tried something like http://www.mobilefun.co.uk/mobile-broadban...rsal-p21427.htm to improve their mobile braodband signal? We're on 3, and- being out in the Fens- we put the dongle in a waterproof tube on our wind turbine mast, to get a reasonable signal.

 

Obviously, this means the dongle gets cold and damp, so I was wondering if anyone had tried something like that external aerial to improve their signal, and if so what results they found?

[Guest]

I was just wondering if anyone had tried something like http://www.mobilefun.co.uk/mobile-broadban...rsal-p21427.htm to improve their mobile braodband signal? We're on 3, and- being out in the Fens- we put the dongle in a waterproof tube on our wind turbine mast, to get a reasonable signal.

 

Obviously, this means the dongle gets cold and damp, so I was wondering if anyone had tried something like that external aerial to improve their signal, and if so what results they found?

 

The ones you've linked to look like they are directional so you have to align it each time you moor and if you don't know where your nearest base station is this will be impossible.

 

I unearthed one on here a few months ago after asking a similar question - can't find it now but if I do I will post the info, up

Edited January 2, 2010 by MJG

[Robbo]

Here's another site that does them http://www.connextech.co.uk/, if you modem has a socket for a external aerial use that and not those stick on things.

[Guest]

Here's another site that does them http://www.connextech.co.uk/, if you modem has a socket for a external aerial use that and not those stick on things.

 

Cheers Robbo this one-

 

http://www.connextech.co.uk/3g-external-hi...0203-n-91-p.asp

 

Was similar to the one I was shown - omni directional too so way better for a boat (Bluddy expensive though ) a hundred notes!!

 

There is I'n sure cheaper versions around.

[johnjo]

£15.95 inc: P&P

 

Not exactly the same as the one I bought last year but very similar, works a treat.

 

This one is for the 02 network but can't see why it wouldn't work for '3' or 'Orange' etc:

 

Just need to check that the connector will fit your dongle. You can get adaptors if not, look on Ebay

 

http://cgi.ebay.co.uk/Antenna-3G-Broadband...=item5ad610f2cb

Edited January 2, 2010 by johnjo

[ditchcrawler]

£15.95 inc: P&P

 

Not exactly the same as the one I bought last year but very similar, works a treat.

 

This one is for the 02 network but can't see why it wouldn't work for '3' or 'Orange' etc:

 

Just need to check that the connector will fit your dongle. You can get adaptors if not, look on Ebay

 

http://cgi.ebay.co.uk/Antenna-3G-Broadband...=item5ad610f2cb

I said its good for 3 and the picture shows a 3 dongle. Any idea how long the cable is?

[johnjo]

I said its good for 3 and the picture shows a 3 dongle. Any idea how long the cable is?

 

3 refers to the 3G mobile wifi network.

 

The dongle shown is a Huawei. Some of them, like phones, may locked to only accept an '02' SIM, not sure about that though.

 

The cable length is aprox: 35"

Edited January 2, 2010 by johnjo

[ditchcrawler]

3 refers to the 3G mobile wifi network.

 

The dongle shown is a Huawei. Some of them, like phones, may locked to only accept an '02' SIM, not sure about that though.

 

The cable length is aprox: 35"

Not sure we are talking about the same one.

I was referring to this one

http://cgi.ebay.co.uk/Antenna-3G-Broadband...=item5ad610f2cb

and the photo shows it plugged into a 3 Mobile dongle, but if the lead is less than a meter its not a lot of use to me as it would not reach out of the boat on to the roof.

I almost ordered one

[Yoda]

The dongle is tuned to the selected band that it advertises. If you know what the transmission and receive frequencies are you can get a proper antenna for your boat. You can also make your own vertical antenna using twin wire flex.

[johnjo]

Not sure we are talking about the same one.

I was referring to this one

http://cgi.ebay.co.uk/Antenna-3G-Broadband...=item5ad610f2cb

and the photo shows it plugged into a 3 Mobile dongle, but if the lead is less than a meter its not a lot of use to me as it would not reach out of the boat on to the roof.

I almost ordered one

 

 

For some reason your link won't work, but yes it's the same one. If you look down the ad, you'll see a list of dongles it's compatable with and other info.

 

The dongle shown is an example only.

 

I'll have a look around and see if I can find an extention cable, I know they are available, as I have one.

[johnjo]

This has a 3mt cable and terminates in a CRC9 connector suitable for the Huawei dongles. Not sure if the frequency range is correct though, although it does state for 3G mobile. I thought 3G was 2.4MHz.

 

Hopefully someone who is more conversant with Mobile B/Band will help?

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?Vie...e=STRK:MEWAX:IT

[ditchcrawler]

This has a 3mt cable and terminates in a CRC9 connector suitable for the Huawei dongles. Not sure if the frequency range is correct though, although it does state for 3G mobile. I thought 3G was 2.4MHz.

 

Hopefully someone who is more conversant with Mobile B/Band will help?

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?Vie...e=STRK:MEWAX:IT

 

This is not the one I use but I got it as a spare in case mine dropped in the cut.

 

On the box that my free 3 moble ZTE MF627 came in

HSDPA/WCDMA 2100MHZ

GSM/GPRS/EDGE 900/1800MHZ

[johnjo]

This is not the one I use but I got it as a spare in case mine dropped in the cut.

 

On the box that my free 3 moble ZTE MF627 came in

HSDPA/WCDMA 2100MHZ

GSM/GPRS/EDGE 900/1800MHZ

 

That's the same as my spare, free from '3'. It dosen't have a CRC9 connection.

 

The one I use on the boat does but I can't remember the model No: sorry.

[Yoda]

I forgot to add to my earlier bit that you will also need to know what the polarisation is ie vertical, horizontal, circular or crossed. If you don't know what it is when you are buying or making antennas, you could find that it produces virtually no signal at all.

[alan_fincher]

Although a number of Huawei modems are listed there, not all the Huawei modems that '3' have marketed have capability of an external antenna plug in.

 

We have the Huawei E220, '3's standard offering for PAYG at the time, and, (like the subsequently acquired 'free' ZTE MF627), it does not offer this facility.

 

So before ordering up an antenna, you need to be certain your modem has the relevant socket.

[Justme]

We use a directional one to get the signal from a mast 6 miles away (with hills & valleys). Without it the signal strength is 2 bars & drops out all the time. With it is 3 bars & hardly drops out.

 

Ours cost about teh same but has more than double the dbi gain.

 

 

From a seller on ebay

Edited January 2, 2010 by Justme

[ditchcrawler]

Although a number of Huawei modems are listed there, not all the Huawei modems that '3' have marketed have capability of an external antenna plug in.

 

We have the Huawei E220, '3's standard offering for PAYG at the time, and, (like the subsequently acquired 'free' ZTE MF627), it does not offer this facility.

 

So before ordering up an antenna, you need to be certain your modem has the relevant socket.

The one I normally use is a ZTE MF622 with a socket on the back, for 15 quid I will risk it.

With respect to polarisation, I have a Boatersphone Aerial for my phone on Vodafone and have it raked at 45 deg and NEVER failed to get a usable signal, even in Braunston

[starman]

The one I normally use is a ZTE MF622 with a socket on the back, for 15 quid I will risk it.

With respect to polarisation, I have a Boatersphone Aerial for my phone on Vodafone and have it raked at 45 deg and NEVER failed to get a usable signal, even in Braunston

 

That's what we have with a short adaptor cable from Boaters Phone Co that plugs into the socket and links to an external magnetic mount aerial

[Guest]

That's what we have with a short adaptor cable from Boaters Phone Co that plugs into the socket and links to an external magnetic mount aerial

 

That will be one of these, which is the ones I was babbling on about earlier in the thread,

 

 

http://boatersphone.com/antennas.htm

[Nickhlx]

Aerials is one of my main interests in amateur radio...

 

People need to be aware that the cable used to connect the aerial to the dongle could be giving as much loss as the claimed gain of the aerial and even MORE ! The typical loss of the small diameter cable at these frequencies, is around 0.5 dB for each metre of length, so a 5 metre cable is losing AT LEAST 2.5 dB and probably nearer 3.5dB including connector losses. So, to "stand still", the aerial NEEDS to be giving a genuine, say 3.5dB, to be worth spending ? £10+ on....

 

However, a remote aerial should give better results, partly from height gain and partly getting it out of the hash around the PC and getting it outside the shell of the boat, so it will almost certainly be worthwhile, assuming the cable is kept as short as possible to minimise that cable loss and connections are good.

 

Cable loss is pretty much directly related to cable diameter, with the bigger diameters being less lossy. The better aerials will have larger cables fitted. If it's possible to replace the tiny cable with something less lossy of the correct impedance ( 50 ohm probably) and also get back into the original comnnector (maybe via an adaptor which will lose about 1/2 dB ) the net gain might be 2 to 5 dB, depending on the cable length you need. The shortest cable length you can get away with will save loss too.

 

If you are starting from scratch ( as I am ) the best compromise will be as follows...

 

1) Site the dongle on the roof of the boat, inside next to a mushroom vent ( use self adhesive velcro pads )

2) Use a HIGH QUALITY 2M or 3M USB lead to connect the PC to the dongle - this is because the dongle needs a fair bit of power and the bigger cables will

hopefully have bigger conductors for the power, minimising drop.

3) With a decent external aerial use the shortest length of quality cable between the aerial and the dongle, probably entering via a mushroom vent.

 

The fact is a "stick aerial" with around 6 dBd gain ( which is 6 dB with respect to a dipole) is about all you will find in practice without spend a huge amount of money. This is a co-linear type of aerial and doesn't need a ground plane like a magnetic mount.

 

Aerials claiming "15dB gain" for e.g £30 will likely be rubbish - note the lack of the second "d" which effectively means "gain compared to what - a piece of damp string ?" so they can't be done for false claims...

 

Mount the white stick about 1/2 to 1 metre above the roof, so it is clear of the roof fittings but not too high to be a problem for bridges ( or make it "hinged" so it can be laid flat) This type of aerial is omni-directional, so you won't need to point it. Thetre is little point going much higher than a metre above the roof.

 

For the best signal, a Yagi aerial will be needed, and it will need to be rotatable to point at the nearest transmitter - this should also be about 50 -100 cms above the roof. Yagis can be "horizontal or vertical" - I do not know what polarisation is transmitted and it may vary anyway - try rotating the aerial axially when pointing at the cell.

 

Bear in mind that the higher the gain, the more susceptible the signal being received will be to boat movement - the wavelength at dongle frequencies is only approx 15cms, so moving it only 7.5 cms will be from a max to a minimum - moving the boat back or forwards less than a foot or two could make a world of difference and is worth trying in worst cases. Being out in the open will be really helpful too ( i.e. fields immediately around you, not hills) Being near a town ( less than a mile) is likely to help as there will probably be a cellsite in town.

 

I am shortly doing this for our boat - it's not pressing for me at the moment as we are at the west end of the K and A, and signals are good to beyond Hungerford, going from the East end....

 

My spec will have most of the above including:

 

1) Dongle on ceiling next to mushroom vent

2) A "white stick aerial" with the shortest, fattest cable I can use ( cable around 6mm to 10mm diameter) on a hinged 1M pole ( laid flat when moving)

3) A directional Yagi aerial for the weakest patches - hopefully around 12dBd gain

4) I have a decent 3M USB cable - it cost £20 !

 

The system does have its limitations, but the above will make the best of it and be immensely better than "a dongle on a desk next to the PC"

 

Hope that helps

 

Nick

 

Edited January 3, 2010 by Nickhlx

[Guest]

Aerials is one of my main interests in amateur radio...

<SNIP>

 

Nick

 

 

Excellent post Nick cheers.

[Nickhlx]

Excellent post Nick cheers.

 

 

Thanks,

 

If anyone would like an opinion on proposed bits I would be glad to help... I am researching bits for mine from time to time and will post findings as and when.

 

Nick

Edited January 3, 2010 by Nickhlx

[johnjo]

Thanks for that 'Nickhlx' just the sort of info we needed.

 

Have you looked at the link :-

 

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?Vie...e=STRK:MEWAX:IT

 

I posted earlier and if so what do you think of it, taking the price into consideration?

 

I'm tempted to buy as it has 3mts of cable which would suit my needs. My present aerial only has 1mt so I use a 3mt USB lead which means the dongle hangs just below the cabin roof, and gets in the way and I just know someone will walk into it and drag the laptop onto the floor, me probably

 

John

[Nickhlx]

Thanks for that 'Nickhlx' just the sort of info we needed.

 

Have you looked at the link :-

 

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?Vie...e=STRK:MEWAX:IT

 

I posted earlier and if so what do you think of it, taking the price into consideration?

 

I'm tempted to buy as it has 3mts of cable which would suit my needs. My present aerial only has 1mt so I use a 3mt USB lead which means the dongle hangs just below the cabin roof, and gets in the way and I just know someone will walk into it and drag the laptop onto the floor, me probably

 

John

 

 

I would get one of the magmounts with the "spring" in the middle with the most gain, as the price seems little more - the cable is RG174 which is 50 ohm (fine) but is only approx 2.5 mm OD and quite lossy at these fequencies. However replacing it is probably not practical unless you have a small "workshop" and can do such things. You might be able to shorten it though which would help a bit if you can re-solder the connector on a shorter length.

 

You could then mount the aerial on the roof about a foot or two away from a mushroom vent and mount the dongle on the roof inside, near the same vent.

 

If you can, mount the aerial on a biscuit tin (lid) at least 15cms diameter ( e.g a Cadbury's Roses tin ) and try raising it above the roof on e.g a wooden stool to get it a bit higher - see if that improves things at all ?

 

Note - The magmounts MUST have a "groundplane" to work - this means they must sit on a metal sheet at least a wavelength long (15cms) - it doesn't have to be magnetic though and aluminium would work... i.e. do not tape them to a wooden pole in an attempt to raise them.

 

Nick