I need to buy an external High Gain Antenna to plug into my mobile
phone. I need to operate the phone in a very remote area, where the
signal is at best, only one bar on the display. I will mount the
antenna on a pole on the roof, so I will need advise on cable as well.
Can anybody tell me where to buy such a beast, thanks.

Country??

Mark wrote:
I need to buy an external High Gain Antenna to plug into my mobile
phone. I need to operate the phone in a very remote area, where the
signal is at best, only one bar on the display. I will mount the
antenna on a pole on the roof, so I will need advise on cable as well.
Can anybody tell me where to buy such a beast, thanks.

Mark wrote:
I need to buy an external High Gain Antenna to plug into my mobile
phone. I need to operate the phone in a very remote area, where the
signal is at best, only one bar on the display. I will mount the
antenna on a pole on the roof, so I will need advise on cable as well.
Can anybody tell me where to buy such a beast, thanks.

Most mobile phone accessory shops have external antennas for sale. These
antennas are designed for use in a car, but work fine without. The cable
is not very long (2-4m), but adding a chunk of 50Ohm RG58-type cable is
possible. I'd cut the cable close to the antenna to preserve a decent
bit of the original cable (with the connector matching your phone) on
the phone side for comfort.
If you know where the closest base station is than you can add a
parabolic reflector and aim for it to increase the signal. Just google
for wifi and parabolic and scale according to the frequency you use. If
you are using the 800 or 900 Mhz bands the reflector can get quite large
though.

Markus

On Tue, 22 Mar 2005 06:39:27 +1100, Bob Bob
wrote:

Country??

Spain

On Mon, 21 Mar 2005 23:15:32 +0100, Markus Baertschi
wrote:

Mark wrote:
I need to buy an external High Gain Antenna to plug into my mobile
phone. I need to operate the phone in a very remote area, where the
signal is at best, only one bar on the display. I will mount the
antenna on a pole on the roof, so I will need advise on cable as well.
Can anybody tell me where to buy such a beast, thanks.

Most mobile phone accessory shops have external antennas for sale. These
antennas are designed for use in a car, but work fine without. The cable
is not very long (2-4m), but adding a chunk of 50Ohm RG58-type cable is
possible. I'd cut the cable close to the antenna to preserve a decent
bit of the original cable (with the connector matching your phone) on
the phone side for comfort.
If you know where the closest base station is than you can add a
parabolic reflector and aim for it to increase the signal. Just google
for wifi and parabolic and scale according to the frequency you use. If
you are using the 800 or 900 Mhz bands the reflector can get quite large
though.

Markus

Is there a rough calculation on how high I should be aiming to mount
the Antenna (law of diminishing returns, and all that). A half
informed friend said I should use a YAGI antenna, is he correct? If so
where do I buy a suitable one in the UK or Europe for Spain.

I know where the base station is, where do I buy a parabolica to
match, how does one mount the Antenna on the parabolica? what size
dish is a good size to start with? would an old TV Satellite dish do
it? Do I ground the dish?

A specific vendor I cant help you with then (I am in Australia)

I would think that many large phone accessory distributors could sell
you one. Otherwise look at some more professional antenna manufacturers.
They often have yagis available in the phone frequency range. Take care
with finding the right connector and keep the coax loss low.

It might also be cheaper to get a simple mobile gain antenna and mount
it high. Get it clear of ground clutter and dont be afraid to move it
around for the strongest signal (before bolting it in place)

You'll need to know the operating frequency of your phone. If it is a
multi band thing you'll have to find the freq of your nearest node. This
will also determine the coax loss/cost as well. I would suggest that if
you are running 10 metres or so to use LMR400. It isnt the lowest loss
cable around but it is still easy to terminate and seems to have the
best cost/loss numbers. There are a number of sites around that allow
you to calculate cable loss at specific frequencies. Of course it also
depends on whether it is available where you are.

To give you an idea a 10m run of coax at 900MHz with LMR400 is about
1.3dB loss. Using RG213 the loss is about twice that and the cable cost
is higher! RG58 has a whopping 5-6dB loss. I find it strange that mobile
phone antennas have such horrible cable.

Hope this helps

Cheers Bob

Mark wrote:
On Tue, 22 Mar 2005 06:39:27 +1100, Bob Bob
wrote:


Country??


Spain

On Tue, 22 Mar 2005 19:24:43 +1100, Bob Bob
wrote:

A specific vendor I cant help you with then (I am in Australia)

I would think that many large phone accessory distributors could sell
you one. Otherwise look at some more professional antenna manufacturers.
They often have yagis available in the phone frequency range. Take care
with finding the right connector and keep the coax loss low.

It might also be cheaper to get a simple mobile gain antenna and mount
it high. Get it clear of ground clutter and dont be afraid to move it
around for the strongest signal (before bolting it in place)

You'll need to know the operating frequency of your phone. If it is a
multi band thing you'll have to find the freq of your nearest node. This
will also determine the coax loss/cost as well. I would suggest that if
you are running 10 metres or so to use LMR400. It isnt the lowest loss
cable around but it is still easy to terminate and seems to have the
best cost/loss numbers. There are a number of sites around that allow
you to calculate cable loss at specific frequencies. Of course it also
depends on whether it is available where you are.

To give you an idea a 10m run of coax at 900MHz with LMR400 is about
1.3dB loss. Using RG213 the loss is about twice that and the cable cost
is higher! RG58 has a whopping 5-6dB loss. I find it strange that mobile
phone antennas have such horrible cable.

Hope this helps

Cheers Bob

Mark wrote:
On Tue, 22 Mar 2005 06:39:27 +1100, Bob Bob
wrote:


Country??


Spain

Thanks Bob, managed to find a shop that had a Yagi which from memory
is in the 850 - 950 Mhz range. Also bought 2 x 3 metre length antenna
poles and a wall bracket, the guy in the shop seemed to know his stuff
and I took his advice on the cable. I will put this lot up some time
this week, I will let you know if this improves things, thanks again
to everybody who helped, isn't the internet a marvellous thing, still
never cease's to amaze me?

Mark in Spain
(remove the X to reply)