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T i m February 12th 05 09:26 PM

DIY DX WiFi?
 
Hi All,

I would like to extend the range of a home WiFi link (better signal
strength down to the workshop) and wondered if anyone here had
*actually* built / tested one of those DIY 'can' type antenna /
reflectors / whatever?

What type of interface makes the job easier (USB 'dongle', remote usb
'compact type' , PCI / PCCard SMA connector etc)?

I guess something fairly directional would probably be best ..?

All the best ..

T i m





Mike February 12th 05 11:25 PM


"T i m" wrote in message
...
Hi All,

I would like to extend the range of a home WiFi link (better signal
strength down to the workshop) and wondered if anyone here had
*actually* built / tested one of those DIY 'can' type antenna /
reflectors / whatever?


The illegal ones you mean ? :-)



T i m February 12th 05 11:37 PM

On Sat, 12 Feb 2005 23:25:25 -0000, "Mike" wrote:


"T i m" wrote in message
.. .
Hi All,

I would like to extend the range of a home WiFi link (better signal
strength down to the workshop) and wondered if anyone here had
*actually* built / tested one of those DIY 'can' type antenna /
reflectors / whatever?


The illegal ones you mean ? :-)


Are they?

I thought it was 'ok' as long as you didn't exceed the max power into
the thing?

So I take it it's the radiated power that is 'measured' and if so at
what point around the antenna (ie if it's directional what is gained
at the front will be lost at the side won't it?)

All the best ..

T i m



John February 13th 05 07:36 AM


"T i m" wrote in message
...
Hi All,

I would like to extend the range of a home WiFi link (better signal
strength down to the workshop) and wondered if anyone here had
*actually* built / tested one of those DIY 'can' type antenna /
reflectors / whatever?

What type of interface makes the job easier (USB 'dongle', remote usb
'compact type' , PCI / PCCard SMA connector etc)?

I guess something fairly directional would probably be best ..?

All the best ..

T i m





this any good http://www.usbwifi.orcon.net.nz/ page can be slow to
load...



Dave Stanton February 13th 05 08:42 AM

On Sat, 12 Feb 2005 23:37:36 +0000, T i m wrote:

On Sat, 12 Feb 2005 23:25:25 -0000, "Mike" wrote:


"T i m" wrote in message
. ..
Hi All,

I would like to extend the range of a home WiFi link (better signal
strength down to the workshop) and wondered if anyone here had
*actually* built / tested one of those DIY 'can' type antenna /
reflectors / whatever?


The illegal ones you mean ? :-)


Are they?

I thought it was 'ok' as long as you didn't exceed the max power into the
thing?

So I take it it's the radiated power that is 'measured' and if so at what
point around the antenna (ie if it's directional what is gained at the
front will be lost at the side won't it?)

All the best ..

T i m


You need to look at some simple explanations of antenna theory. a
directional antenna can have side lobes for instance.

Dave

--
For what we are about to balls up may common sense prevent us doing it
again
in the future!!

T i m February 13th 05 10:24 AM

On Sun, 13 Feb 2005 07:36:02 -0000, "John"
wrote:


I would like to extend the range of a home WiFi link (better signal
strength down to the workshop) and wondered if anyone here had
*actually* built / tested one of those DIY 'can' type antenna /
reflectors / whatever?


this any good http://www.usbwifi.orcon.net.nz/ page can be slow to
load...

Cool, a real DIY page, thanks! ;-)

T i m

Gordon Henderson February 13th 05 10:32 AM

In article ,
T i m wrote:
Hi All,

I would like to extend the range of a home WiFi link (better signal
strength down to the workshop) and wondered if anyone here had
*actually* built / tested one of those DIY 'can' type antenna /
reflectors / whatever?


If you don't have true line of sight, then you're shafted.

Even with line of sight, theses a thing called the fresnel zone
which extends out in a cone from the direct line of sight. There are
various calculations required to calculate this, but for most domestic
appications, like of sight with a cylinder of a few metres diameter will
give you a good signal.

What type of interface makes the job easier (USB 'dongle', remote usb
'compact type' , PCI / PCCard SMA connector etc)?


Forget the USB ones - go for a pair of WiFi Bridges. Preferably ones
designed for outdoor use with power over Ethernet. That way, you just
plug one into the house LAN and the other into the workshop LAN.

I've built community broadband networks with various units - the favourite
is the Smart Bridges range - they have various flat-plat directional
units which are reasonably good in bridge mode, and more importantly,
weather proof and take power over Ethernet. The ones we use are about
7" square.

Power over Ethernet means that you just run one cable to the outdoor unit,
and that cable is a digital data cable, rather than an analogue RF signal,
which at the power levels avalable to you in WiFi applications is woefully
weak and prone to cable, and connector losses.

You can built your own "pringle can" antennae and buy external antennae to
fit onto some units, but then you have the problems of weather proofing
it. You really do want the units outdoors pointing at each other, don't
fool yourself with the advertising blurb that comes with them! You might
get a signal through a wall if the antennae are prepindicular to it,
but at an angle, pythagoras comes into play and the wall sudenly becomes
a lot "thicker" that it might appear...

I have one link that 7.5Km long, and it's providing and acceptable signal
for the home user, but they have a rather large grid parabolic reflector
on the chimney of their house pointing back to the base station... So
with care and the right kit, quite a lot is possible.

Saying all that, you might be lucky with ordinary kit - radio waves do
reflect - but they will be severely attentuated by trees with leaves on
-I have some graphs that look great in the winter... Come spring when
the sap starts to rise and you can see the signal strength drop )-:

Drop me an email if you want more details - it's actually been a while
since I looked at the market and devices, but IIRC we were paying
something like £150 each for the smartBridge units...

Gordon

T i m February 13th 05 10:38 AM

On Sun, 13 Feb 2005 08:42:52 +0000, Dave Stanton
wrote:



So I take it it's the radiated power that is 'measured' and if so at what
point around the antenna (ie if it's directional what is gained at the
front will be lost at the side won't it?)

All the best ..

T i m


You need to look at some simple explanations of antenna theory. a
directional antenna can have side lobes for instance.


Indeed, but I was just questioning if the 'rules' covered power to the
antenna or radiated from it?

The problem I have had go like this ..

I have used a USB (V1.1) WiFi thingy (not 'dongle') on a 5m single
port repeater and it's own 3m lead and that allowed me to position the
remote end in a good place (good height / behind a window etc).
Because of issues with the PC / USB I've made use of a PCI 11g card
with antenna that attaches directly to the rear but the PC sheilds the
RF to some degree. I could get one of those little remote stands to
take the std 'rubber duck' (probably cheaper than buying a complete
'mushroom') but leads / connectors are all lossy and are sorta self
defeating?

The (nearly) ultimate solution (outside of running cable) would be a
Ethernet WiFi box (like an AP) but I don't have one and they aren't
cheap? Also, it would need power and that may not be available near
the optimum placement of the unit.

Maybe I'll go back down the USB route as it can easily be 'remoted',
is host powered and the cables / units are pretty cheap now (I only
need .11b)

All the best ..

T i m

Dave Stanton February 13th 05 11:18 AM


Indeed, but I was just questioning if the 'rules' covered power to the
antenna or radiated from it?

All the best ..

T i m


With most things RF and goverment rules its radiated power that counts,
that way it covers antennas with gain.... crafty blighters !!

Dave

--
For what we are about to balls up may common sense prevent us doing it
again
in the future!!

T i m February 13th 05 11:39 AM

On Sun, 13 Feb 2005 11:18:01 +0000, Dave Stanton
wrote:


Indeed, but I was just questioning if the 'rules' covered power to the
antenna or radiated from it?

All the best ..

T i m


With most things RF and goverment rules its radiated power that counts,
that way it covers antennas with gain.... crafty blighters !!


I suppose a problem with that could be 'how' that signal is radiated
and how 'close' to the upper tested limits the manufacturers sail?

ie, One make / model of WiFi kit is 'known' to work better (afa range
lets say) than may others? Or have more options that may help
propagation.

Ignoring the risk to humans from microwaves, I think what should be
important to those who set the rules is what proportion of signal
get's out past my boundries. Ie, if I lived in a Faraday cage I could
(should be able to) use whatever power I like ;-)

So, if I want to get a signal down to my workshop I should be allowed
to do whatever re the (max) power available (I'm talking antenna here)
as long as the rf that actually makes it out of my house is below the
permitted maximum?

I know the above is pretty unworkable in the real world but you get
the idea ...

All the best ..

T i m



T i m February 13th 05 11:58 AM

On Sun, 13 Feb 2005 10:32:18 +0000 (UTC),
(Gordon Henderson) wrote:

In article ,
T i m wrote:
Hi All,

I would like to extend the range of a home WiFi link (better signal
strength down to the workshop) and wondered if anyone here had
*actually* built / tested one of those DIY 'can' type antenna /
reflectors / whatever?


If you don't have true line of sight, then you're shafted.


I sorta do Gordon. From the window in the spare (junk) room I can
clearly 'see' the workshop.

Even with line of sight, theses a thing called the fresnel zone
which extends out in a cone from the direct line of sight. There are
various calculations required to calculate this, but for most domestic
appications, like of sight with a cylinder of a few metres diameter will
give you a good signal.


Understood.

What type of interface makes the job easier (USB 'dongle', remote usb
'compact type' , PCI / PCCard SMA connector etc)?


Forget the USB ones - go for a pair of WiFi Bridges. Preferably ones
designed for outdoor use with power over Ethernet. That way, you just
plug one into the house LAN and the other into the workshop LAN.


Ok ..

I've built community broadband networks with various units - the favourite
is the Smart Bridges range - they have various flat-plat directional
units which are reasonably good in bridge mode, and more importantly,
weather proof and take power over Ethernet. The ones we use are about
7" square.


Is this 'legal' then Gordon. That panel seems likely to gave a gain
greater than unity?

Power over Ethernet means that you just run one cable to the outdoor unit,
and that cable is a digital data cable,


Like USB . didn't know you could get such but it makes sense.

rather than an analogue RF signal,
which at the power levels avalable to you in WiFi applications is woefully
weak and prone to cable, and connector losses.


Indeed ;-(

You can built your own "pringle can" antennae and buy external antennae to
fit onto some units, but then you have the problems of weather proofing
it. You really do want the units outdoors pointing at each other, don't
fool yourself with the advertising blurb that comes with them! You might
get a signal through a wall if the antennae are prepindicular to it,
but at an angle, pythagoras comes into play and the wall sudenly becomes
a lot "thicker" that it might appear...


Understood ;-)

I have one link that 7.5Km long, and it's providing and acceptable signal
for the home user, but they have a rather large grid parabolic reflector
on the chimney of their house pointing back to the base station... So
with care and the right kit, quite a lot is possible.


Hmm, so if you were to 'reflect' (concentrate) the signal would that
stay within the rules? What would be the practical difference then re
using a Yagi?

Saying all that, you might be lucky with ordinary kit - radio waves do
reflect - but they will be severely attentuated by trees with leaves on
-I have some graphs that look great in the winter... Come spring when
the sap starts to rise and you can see the signal strength drop )-:


All concrete here ;-) I *did* have a pretty reliable link using a
Netgear AP to a Netgear USB unit (not dongle) but the AP seems to have
died and a Belkin WiFi router has taken it's place for the moment
running in AP mode.

Drop me an email if you want more details - it's actually been a while
since I looked at the market and devices,


Thanks for the kind offer ;-)

but IIRC we were paying
something like £150 each for the smartBridge units...


Ouch! A bit outside my league I'm afraid .. hence the 'DIY' interest
...

All the best ..

T i m

Dave Stanton February 13th 05 12:07 PM

On Sun, 13 Feb 2005 11:39:20 +0000, T i m wrote:

On Sun, 13 Feb 2005 11:18:01 +0000, Dave Stanton wrote:


Indeed, but I was just questioning if the 'rules' covered power to the
antenna or radiated from it?

All the best ..

T i m


With most things RF and goverment rules its radiated power that counts,
that way it covers antennas with gain.... crafty blighters !!


I suppose a problem with that could be 'how' that signal is radiated and
how 'close' to the upper tested limits the manufacturers sail?

ie, One make / model of WiFi kit is 'known' to work better (afa range lets
say) than may others? Or have more options that may help propagation.

Ignoring the risk to humans from microwaves, I think what should be
important to those who set the rules is what proportion of signal get's
out past my boundries. Ie, if I lived in a Faraday cage I could (should be
able to) use whatever power I like ;-)

So, if I want to get a signal down to my workshop I should be allowed to
do whatever re the (max) power available (I'm talking antenna here) as
long as the rf that actually makes it out of my house is below the
permitted maximum?

I know the above is pretty unworkable in the real world but you get the
idea ...

All the best ..

T i m


Thats why most things come with very ineffecient antennas and are ltd to
low power. Even Faraday cages can leak!!

Dave

--
For what we are about to balls up may common sense prevent us doing it
again
in the future!!

Rob Morley February 13th 05 12:27 PM

In article , "T i m"
says...
On Sun, 13 Feb 2005 11:18:01 +0000, Dave Stanton
wrote:


Indeed, but I was just questioning if the 'rules' covered power to the
antenna or radiated from it?

All the best ..

T i m


With most things RF and goverment rules its radiated power that counts,
that way it covers antennas with gain.... crafty blighters !!


I suppose a problem with that could be 'how' that signal is radiated
and how 'close' to the upper tested limits the manufacturers sail?

ie, One make / model of WiFi kit is 'known' to work better (afa range
lets say) than may others? Or have more options that may help
propagation.

Ignoring the risk to humans from microwaves, I think what should be
important to those who set the rules is what proportion of signal
get's out past my boundries. Ie, if I lived in a Faraday cage I could
(should be able to) use whatever power I like ;-)

So, if I want to get a signal down to my workshop I should be allowed
to do whatever re the (max) power available (I'm talking antenna here)
as long as the rf that actually makes it out of my house is below the
permitted maximum?

I know the above is pretty unworkable in the real world but you get
the idea ...

The fact is that if the RF doesn't escape from your property nobody
is going to know about it, so what's the worry?


tony sayer February 13th 05 12:50 PM

In article , T i m
writes
On Sat, 12 Feb 2005 23:25:25 -0000, "Mike" wrote:


"T i m" wrote in message
. ..
Hi All,

I would like to extend the range of a home WiFi link (better signal
strength down to the workshop) and wondered if anyone here had
*actually* built / tested one of those DIY 'can' type antenna /
reflectors / whatever?


The illegal ones you mean ? :-)


Are they?

I thought it was 'ok' as long as you didn't exceed the max power into
the thing?

So I take it it's the radiated power that is 'measured' and if so at
what point around the antenna (ie if it's directional what is gained
at the front will be lost at the side won't it?)

All the best ..

T i m



100 milliwatts ERP Effected Radiated Power. If you don't want to make a
cantenna then this lot do some very good ones. We have a link in daily
use that does 6.1 kilometres and its fine:))

http://www.solwise.co.uk/wireless-outdoorantenna-24.htm
--
Tony Sayer


Dave Liquorice February 13th 05 02:50 PM

On Sun, 13 Feb 2005 10:32:18 +0000 (UTC), Gordon Henderson wrote:

I have one link that 7.5Km long, and it's providing and acceptable
signal for the home user, but they have a rather large grid
parabolic reflector on the chimney of their house pointing back to
the base station... So with care and the right kit, quite a lot is
possible.


The network I'm part of has many links of similar length or much
longer, the longest is not far short of 20km. The longer hops use 24"
dishes each end, the shorter ones long or short enclosed yagis
depending on the distance.

The real key is line of sight and reasonable antenneas. Getting a
signal down to a workshop shouldn't be a problem. I should imagine
that you could get away with the stick on window patch jobbies at both
ends assuming windows in suitable places near the PCs.

--
Cheers
Dave. pam is missing e-mail




Christopher Key February 13th 05 03:44 PM

T i m wrote:
Hi All,

I would like to extend the range of a home WiFi link (better signal
strength down to the workshop) and wondered if anyone here had
*actually* built / tested one of those DIY 'can' type antenna /
reflectors / whatever?

What type of interface makes the job easier (USB 'dongle', remote usb
'compact type' , PCI / PCCard SMA connector etc)?

I guess something fairly directional would probably be best ..?


http://www.wireless.org.au/~jhecker/helix/

I've used these for receiving from a miniture 2.4GHz video sender with great
success. I'm not sure about the legality of transmitting with one though!

Chris Key



Andy Hall February 13th 05 05:35 PM

On Sun, 13 Feb 2005 12:50:24 +0000, tony sayer
wrote:



100 milliwatts ERP Effected Radiated Power. If you don't want to make a
cantenna then this lot do some very good ones. We have a link in daily
use that does 6.1 kilometres and its fine:))

http://www.solwise.co.uk/wireless-outdoorantenna-24.htm



That's pretty good. Which antennas did you use to do this and how was
alignment done? Was it with a standard 802.11 access point at each
end as well, or did it need something more serious?



--

..andy

To email, substitute .nospam with .gl

John Stumbles February 13th 05 07:00 PM

T i m wrote:
On Sun, 13 Feb 2005 07:36:02 -0000, "John"
wrote:



I would like to extend the range of a home WiFi link (better signal
strength down to the workshop) and wondered if anyone here had
*actually* built / tested one of those DIY 'can' type antenna /
reflectors / whatever?


this any good http://www.usbwifi.orcon.net.nz/ page can be slow to
load...


Cool, a real DIY page, thanks! ;-)


What frequency does sKY TV satellite run at? If it's in the same
ballpark as 802.11 I'd be inclined to try a USB dongle in place of the
head elx (LNB?) of a sky disk to get a bit of directionality.

Mike Deblis February 13th 05 07:49 PM

"T i m" wrote in message
...
Hi All,

I would like to extend the range of a home WiFi link (better signal
strength down to the workshop) and wondered if anyone here had
*actually* built / tested one of those DIY 'can' type antenna /
reflectors / whatever?

What type of interface makes the job easier (USB 'dongle', remote usb
'compact type' , PCI / PCCard SMA connector etc)?

I guess something fairly directional would probably be best ..?


I bought a pair of 15dB gain antenna off eBay - cost about 30 quid the
pair - the are external and very uni-directional and have SMA connectors at
the end of about 2m of very nice coax - came from eastern europe. I have a
Netgear WG602 combined bridge & WAP in my workshop and one in the house -
about 100m apart with several brick walls between - the Netgear boxes say
65% signal strength when the aerials point exactly at each other. The ADSL
gateway / NAT/Firewall/DHCP server is a Netgear DG834. I'm using 128bit WEP
and dedicating the WG602 MAC addresses to each other to prevent people on
the other side of the valley nicking my bandwidth ;-)

Result - broadband on the whole 2 hectare site.

HTH,

Mike



Gordon Henderson February 13th 05 08:10 PM

In article ,
T i m wrote:
On Sun, 13 Feb 2005 11:18:01 +0000, Dave Stanton
wrote:


Indeed, but I was just questioning if the 'rules' covered power to the
antenna or radiated from it?

All the best ..

T i m


With most things RF and goverment rules its radiated power that counts,
that way it covers antennas with gain.... crafty blighters !!


I suppose a problem with that could be 'how' that signal is radiated
and how 'close' to the upper tested limits the manufacturers sail?

ie, One make / model of WiFi kit is 'known' to work better (afa range
lets say) than may others? Or have more options that may help
propagation.


It's not just power - it's got a lot to do with the hardware/software that
decodes the radio signals on the reciever... When I was experimenting
with kit some years back, I found that DLink were utterly rubbish in
that recpet and were very poor at suppressing reflected signals. So
when they were in a good line of sight situation, all was well, but
make it non-line of sight, or in a otherwise poor reception area, and
the reciever would have real problems sorting out duplicate packets -
as a result throughput was dramatically reduced...

They may have fixed this by now, but I did speak to their technical
people, but they didn't seem too interested... As as result when the
time came to deploy several 100 recievers, they didn't get a look-in.

Ignoring the risk to humans from microwaves, I think what should be
important to those who set the rules is what proportion of signal
get's out past my boundries. Ie, if I lived in a Faraday cage I could
(should be able to) use whatever power I like ;-)


I've heard (and no-ones ever refuted this, it *may* be UL!!!) that the
radiated power avalable in the 2.4GHz range is all down to the amount
of radiation a domestic microwave oven is allowed to leak... People make
such song and dance about whinging about the power levels of WiFi when
a mobile phone is allowed to chuck out some 40 times more power...

So, if I want to get a signal down to my workshop I should be allowed
to do whatever re the (max) power available (I'm talking antenna here)
as long as the rf that actually makes it out of my house is below the
permitted maximum?

I know the above is pretty unworkable in the real world but you get
the idea ...


The reality is that no-ones going to come after you ... unless you start
to cause interference... One town we installed in complained that we were
interfering with the town CCTV system - which also used the 2.4GHz band
(it's also knows as the ISM band - Industrial, Scientific and Medical,
used for instrumentation of various sorts, and low power analogue CCTV,
etc.) As our kit was off the shelf stuff, we were inside the limits,
and once we knew that their kit was on the 2,4GHz band, we really
really wondered how they were getting the signal from the cameras back
to the base, as we really couldn't get signals into the areas they were
getting signals...

There are 2.4GHz amiplifiers avalable... However if you are not careful,
you'll end up amplifying noise too. (Signal to noise ratio being important
here) I always try to get the output power set as low as possible which
will maintain a good signal rather than just set it to max. (On units
which allow you to vary the power)

If WiFi is out of the question, I assume you have power down to the
workshop, so looking into Ethernet over mains might be an answer...

Gordon

Gordon Henderson February 13th 05 08:23 PM

In article ,
tony sayer wrote:

100 milliwatts ERP Effected Radiated Power. If you don't want to make a
cantenna then this lot do some very good ones. We have a link in daily
use that does 6.1 kilometres and its fine:))

http://www.solwise.co.uk/wireless-outdoorantenna-24.htm


Yup. With the right kit, you can do wonders. The longest WiFi (802.11b)
link we installed was a shade over 7.5Km. Omni at one end, and a grid
parabolic at the other end.

We also installed a 17.5Km link using 5.8GHz kit with 2' dishes at each
end and very good line of sight... (Which my home broadband comes over!)
It got a little unreliable last year when one of the dishes filled up with
snow driven into it in a gale )-: We also found that it wasn't properly
aligned - we'd just guessed one end because we couldn't see it - it turned
out to be 15 degrees out which over that distance was quite considerable
- we reckoned we were seeing one of the side-lobes rather than the main
beam. It's been rock solid since we went back and aligned the dishes
properly.

Theres a lot of hackers out there who go for distance records - 50
miles or something was the last one I heard about I think, but I gave
up looking as it gets a bit silly - mountian top to mountian top with
dishes the size of cars...

Hm. solwise do power over ethernet kit-

http://www.solwise.co.uk/net-powerline-pl-14pe.htm

£32 quid each for the cheaper level ones - might be worth investigating...

Gordon

Gordon Henderson February 13th 05 08:36 PM

In article ,
T i m wrote:

If you don't have true line of sight, then you're shafted.


I sorta do Gordon. From the window in the spare (junk) room I can
clearly 'see' the workshop.


OK. You are in with a good chance. I'd still go with an outdoor antennae
if possible though.

I've built community broadband networks with various units - the favourite
is the Smart Bridges range - they have various flat-plat directional
units which are reasonably good in bridge mode, and more importantly,
weather proof and take power over Ethernet. The ones we use are about
7" square.


Is this 'legal' then Gordon. That panel seems likely to gave a gain
greater than unity?


I'm not that hot on the technical side of things (Internet, IP, routing,
etc. is my area of expertiese, however you learn a lot when working with
the radio heads!)

As far as I could tell yes - the radios insude the units are matched
the the flatplate (actually they look like a foil pie dish!) units to
keep the ERP to legal levels...

Power over Ethernet means that you just run one cable to the outdoor unit,
and that cable is a digital data cable,


Like USB . didn't know you could get such but it makes sense.


Isn't there is distance limit of USB cables though? If not, it might be
an option in the workshop then. I've run 50M cables to these units in the
past.

rather than an analogue RF signal,
which at the power levels avalable to you in WiFi applications is woefully
weak and prone to cable, and connector losses.


Indeed ;-(


It can be done, but you need expensive cable and connectors - I've used
some units which have external co-ax plugs and cables though, but we
still ran ethernet right up tothe device, then connected it to an omni
or grid parabolic via a veryshort patch lead.


I have one link that 7.5Km long, and it's providing and acceptable signal
for the home user, but they have a rather large grid parabolic reflector
on the chimney of their house pointing back to the base station... So
with care and the right kit, quite a lot is possible.


Hmm, so if you were to 'reflect' (concentrate) the signal would that
stay within the rules? What would be the practical difference then re
using a Yagi?


Yagis, etc. are all just differetn types of antenna. You need a base
station which has a co-ax outlet and a bit of cable to connect to the
antenna. You have to do sums like multiply the output power by the gain
of the antennae then subtract the losses in the cables and connectors -
in extreme cases, adding an external antennae can actually reduce the ERP.

Saying all that, you might be lucky with ordinary kit - radio waves do
reflect - but they will be severely attentuated by trees with leaves on
-I have some graphs that look great in the winter... Come spring when
the sap starts to rise and you can see the signal strength drop )-:


All concrete here ;-) I *did* have a pretty reliable link using a
Netgear AP to a Netgear USB unit (not dongle) but the AP seems to have
died and a Belkin WiFi router has taken it's place for the moment
running in AP mode.


When we did tests, Netgears seemd reasonable, and I have a really old
Belkin at home which I use from time to time and it seems better. DLink
gave the worst performance of the lot of them.

but IIRC we were paying
something like £150 each for the smartBridge units...


Ouch! A bit outside my league I'm afraid .. hence the 'DIY' interest


Indeed - and this is why commnity WiFi projects will never fly )-: It
simply costs to much to build the infrastructure and people just won't
pay the real home install costs - it was costing us something like
£250 per punter in real terms to put a unit on the side/roof of their
house.. charging them £99 which was all they would be prepared to spend
meant we made a loss for a very long time...

Gordon

tony sayer February 13th 05 08:37 PM

In article , Andy Hall
writes
On Sun, 13 Feb 2005 12:50:24 +0000, tony sayer
wrote:



100 milliwatts ERP Effected Radiated Power. If you don't want to make a
cantenna then this lot do some very good ones. We have a link in daily
use that does 6.1 kilometres and its fine:))

http://www.solwise.co.uk/wireless-outdoorantenna-24.htm



That's pretty good. Which antennas did you use to do this and how was
alignment done? Was it with a standard 802.11 access point at each
end as well, or did it need something more serious?



The 16 dB gain ones with the 2.4 Ghz units Seano from the same company
but with "useful" output, pretty close to the aerials so cable losses
were quite low. It's out in the sticks and carries broadband to a small
industrial estate who are still too far of the BT or ntl networks to get
anything useful.

Alignment was very simple as you can see either end from the other....
--
Tony Sayer


tony sayer February 13th 05 08:38 PM

In article , John Stumbles
writes
T i m wrote:
On Sun, 13 Feb 2005 07:36:02 -0000, "John"
wrote:



I would like to extend the range of a home WiFi link (better signal
strength down to the workshop) and wondered if anyone here had
*actually* built / tested one of those DIY 'can' type antenna /
reflectors / whatever?

this any good http://www.usbwifi.orcon.net.nz/ page can be slow to
load...


Cool, a real DIY page, thanks! ;-)


What frequency does sKY TV satellite run at? If it's in the same
ballpark as 802.11 I'd be inclined to try a USB dongle in place of the
head elx (LNB?) of a sky disk to get a bit of directionality.



Up in the 10 to 12 Ghz band....
--
Tony Sayer


Mike February 13th 05 10:20 PM


"T i m" wrote in message
...
On Sat, 12 Feb 2005 23:25:25 -0000, "Mike" wrote:


"T i m" wrote in message
.. .
Hi All,

I would like to extend the range of a home WiFi link (better signal
strength down to the workshop) and wondered if anyone here had
*actually* built / tested one of those DIY 'can' type antenna /
reflectors / whatever?


The illegal ones you mean ? :-)


Are they?

I thought it was 'ok' as long as you didn't exceed the max power into
the thing?


No, it's the ERP that counts (as well as a host of other specs such as
harmonics and IM which come from the transmitter but can be rendered out of
spec by attenna 'gain'.

That said the Wi-Max stuff drives a horse and cart through such limits ! :-)



T i m February 13th 05 11:16 PM

On Sun, 13 Feb 2005 20:36:02 +0000 (UTC),
(Gordon Henderson) wrote:

snip good stuff

Isn't there is distance limit of USB cables though? If not, it might be
an option in the workshop then.


For USB 1(.1) I believe its 5m before it needs to go though a hub. I
think you can have 4 hubs so 5 'segments' giving 25m or so? These
often look like an 'extension lead' but are infact single port hubs.

I've run 50M cables to these units in the
past.


In theory you should be able to go up to 100m for Cat5 ?


Hmm, so if you were to 'reflect' (concentrate) the signal would that
stay within the rules? What would be the practical difference then re
using a Yagi?


Yagis, etc. are all just differetn types of antenna. You need a base
station which has a co-ax outlet and a bit of cable to connect to the
antenna. You have to do sums like multiply the output power by the gain
of the antennae then subtract the losses in the cables and connectors -
in extreme cases, adding an external antennae can actually reduce the ERP.


And it all seems a bit messy .. weird connectors etc?

snip more good stuff

All the best ..

T i m

John Rumm March 14th 05 08:57 PM

T i m wrote:

I would like to extend the range of a home WiFi link (better signal
strength down to the workshop) and wondered if anyone here had
*actually* built / tested one of those DIY 'can' type antenna /
reflectors / whatever?

What type of interface makes the job easier (USB 'dongle', remote usb
'compact type' , PCI / PCCard SMA connector etc)?

I guess something fairly directional would probably be best ..?


You have probably had all the relevant answers already, but I would add
my vote for the solwise kit , we use a fair mount of it without any
problems.

I can't see you having any problems with a standard AP and a yagi
(regarding power levels etc).

The network over mains units may also do what you want assuming you
already have a mains feed out to your workshop.

Myself I just ran a long cat5e down to it ;-) (although the WiFi does
reach anyway)

Best kit to use would be a Wireless AP that has a reverse SMA connector
for the antenna. You can then ethernet it to a suitable location and run
a short RF elad to the yagi.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Capitol March 14th 05 09:34 PM

Didn't build the can antenna, which looked a pig to couple into and was
extremely ungainly, but using a modified double diamond yagi, for
receive and passive reflection, achieved vastly improved range and
directional signal reception, which knocked out the microwave
interference. Check my post on 2.4GHz some weeks ago. Pretty easy to build.

Regards
Capitol

John Rumm March 15th 05 02:11 AM

T i m wrote:

In theory you should be able to go up to 100m for Cat5 ?


Ethernet spec alows for 305m (1000') per segment... if you want more
than that then you need a repeater (i.e. a hub) along the way (and you
can power that over the spare wires in the cat5 if you want!)


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

tony sayer March 15th 05 09:32 AM

In article , John
Rumm writes
T i m wrote:

I would like to extend the range of a home WiFi link (better signal
strength down to the workshop) and wondered if anyone here had
*actually* built / tested one of those DIY 'can' type antenna /
reflectors / whatever?

What type of interface makes the job easier (USB 'dongle', remote usb
'compact type' , PCI / PCCard SMA connector etc)?

I guess something fairly directional would probably be best ..?


You have probably had all the relevant answers already, but I would add
my vote for the solwise kit , we use a fair mount of it without any
problems.


Yes second that. Their 2.4 MHz boxes are a tad more meaty that most high
St supplier ones:)

--
Tony Sayer


Mark Carver March 16th 05 08:59 AM

tony sayer wrote:

You have probably had all the relevant answers already, but I would add
my vote for the solwise kit , we use a fair mount of it without any
problems.



Yes second that. Their 2.4 MHz boxes are a tad more meaty that most high
St supplier ones:)


If you eat Pringles.......

http://www.multiplay.co.uk/columns.asp?uid=8


--
Mark
Please replace invalid and invalid with gmx and net to reply

T i m March 17th 05 06:01 PM

On Mon, 14 Mar 2005 20:57:28 +0000, John Rumm
wrote:

T i m wrote:

I would like to extend the range of a home WiFi link (better signal
strength down to the workshop) and wondered if anyone here had
*actually* built / tested one of those DIY 'can' type antenna /
reflectors / whatever?

What type of interface makes the job easier (USB 'dongle', remote usb
'compact type' , PCI / PCCard SMA connector etc)?

I guess something fairly directional would probably be best ..?


You have probably had all the relevant answers already, but I would add
my vote for the solwise kit , we use a fair mount of it without any
problems.


Hi John (et al) , thanks for the update.

I can't see you having any problems with a standard AP and a yagi
(regarding power levels etc).

Currently I have a Netgear ME102 AP in the back room talking to a
Q-Tec PCMCIA card in the laptop in the workshop (for test purposes)
and it's ok as long as I leave the (steel) door open ;-)

The network over mains units may also do what you want assuming you
already have a mains feed out to your workshop.

Ok ..

Myself I just ran a long cat5e down to it ;-) (although the WiFi does
reach anyway)


I will run Cat5 down there alongside the power (in it's own plastic
tube) but that might not be for a while ..

Best kit to use would be a Wireless AP that has a reverse SMA connector
for the antenna. You can then ethernet it to a suitable location and run
a short RF elad to the yagi.


*IF* I can get some sort of 'box' (Ethernet remote powered doo-dah) up
behind the glass over the doors of the workshop and then I should get
a useable signal with the std ant.

All the best ..

T i m



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