We have a wireless network at work which appears to have gone downhill since the workmen installed PIRs for the burglar alarm.  One of them in particular appears to cause dropped packets the closer a laptop is to it.  Is this possible??  It's not a wireless PIR as far as I know, as I can see some leftover cable he was using which is a multicore (about 10 cores) type similar to phone systems, so I assume this is for the signal aswell as power.  The person in that office swears blind that there were absolutely no problems until the PIR was installed above her desk, and now when I check, about 60% of the packets are being dropped.  Moving her laptop to the opposite side of the room it drops only 5% of packets.  PIRs used to just pick up infrared of your bodyheat, but I think now they are also motion sensors?  Perhaps this means they are sending out a signal and bouncing it off you?  Perhaps this could interfere with wireless networking?

-- 
http://www.petersparrots.com    http://www.insanevideoclips.com    http://www.petersphotos.com

"Sir, your daughter says she loves me, she can't live without me, and wants to marry me."
"And you're asking my permission to marry her?"
"No, I'm asking you to make her leave me the hell alone!!"

"Peter Hucker"  wrote in message 
news:op.uok1gktq4buhsv@fx62.mshome.net...
> think now they are also motion sensors?  Perhaps this means they are 
> sending out a signal and > bouncing it off you?  Perhaps this could 
> interfere with wireless networking?

That could very well be.  Particularly if they operate in the Ghz band.

Options:

1. Set the WAPs to a different channel.  Becareful of channel conflicts if 
you do that,...3 WAPs that are close together with overlapping signals have 
to use 1, 6 & 11 because they have to be separated by a value of 
"5",...unless you are doing "roaming".  You can't have 4 or more overlaping 
because there is not enough room in the channels.

2. Replace the WAPs with ones that run at a higher frequency like the N band 
or the older A  band.  These run at 5ghz instead of the 2.x ghz of the B and 
G's.

3. Have the PIRs moved to a more stategic location that won't get in the way 
of the WLAN.

That's all I can think of.

-- 
Phillip Windell
www.wandtv.com

The views expressed, are my own and not those of my employer, or Microsoft,
or anyone else associated with me, including my cats.
-----------------------------------------------------

Peter Hucker wrote:
> We have a wireless network at work which appears to have gone downhill since the workmen installed PIRs for the burglar alarm.  One of them in particular appears to cause dropped packets the closer a laptop is to it.  Is this possible??  It's not a wireless PIR as far as I know, as I can see some leftover cable he was using which is a multicore (about 10 cores) type similar to phone systems, so I assume this is for the signal aswell as power.  The person in that office swears blind that there were absolutely no problems until the PIR was installed above her desk, and now when I check, about 60% of the packets are being dropped.  Moving her laptop to the opposite side of the room it drops only 5% of packets.  PIRs used to just pick up infrared of your bodyheat, but I think now they are also motion sensors?  Perhaps this means they are sending out a signal and bouncing it off you?  Perhaps this could interfere with wireless networking?
> 

1. You have a device on the wall that works with your security system 
but you don't really know what it is.  If it really is a "PIR" then by 
definition, it is a "Passive InfraRed" detector, which means that it 
receives signals but doesn't send them out ("passive").  And yes, a PIR 
is typically used as a motion detector: 
http://en.wikipedia.org/wiki/Passive_infrared_sensor

2. Just because the installers left some cable behind doesn't mean that 
*all* of the devices they installed are wired to the alarm electronics. 
Very often, a security system installed in an already-built location (as 
compared to one installed during construction) will be a combination of 
wired and wireless detectors.

3. Ask the company that installed the security system. Are some of the 
sensors wireless, and if so, what frequency band do they use?  (AFAIK, 
if you're in the UK, as suggested by one of the groups you posted to, 
wireless security systems are *supposed* to use 868 MHz, but you never 
know). Even if the devices are nominally supposed to use 868 MHz, their 
transmitters may be poorly designed and cause interference in the 2.4GHz 
band of 802.11G.

-- 
Lem -- MS-MVP

To the moon and back with 2K words of RAM and 36K words of ROM.
http://en.wikipedia.org/wiki/Apollo_Guidance_Computer
http://history.nasa.gov/afj/compessay.htm

On Fri, 30 Jan 2009 19:11:10 -0000, Phillip Windell  wrote:

> "Peter Hucker"  wrote in message
> news:op.uok1gktq4buhsv@fx62.mshome.net..
>> think now they are also motion sensors?  Perhaps this means they are
>> sending out a signal and > bouncing it off you?  Perhaps this could
>> interfere with wireless networking?
>
> That could very well be.  Particularly if they operate in the Ghz band.

They're not wireless themselves, unless you're referring to the signal they put out to bounce of an intruder?

> Options:
>
> 1. Set the WAPs to a different channel.

It's causing equal problems with two WAPs I tried, one is channel 11, one is channel 6.

> Becareful of channel conflicts if
> you do that,...3 WAPs that are close together with overlapping signals have
> to use 1, 6 & 11 because they have to be separated by a value of
> "5",...unless you are doing "roaming".  You can't have 4 or more overlaping
> because there is not enough room in the channels.

I tend to have just enough WAPs to cover every area, and have found that if they are close, I need a difference of only TWO channels (eg use channel 3 and 5), and if they are only just visible from one point, then a gap of 1 is enough (eg using channel 4 and 5).

What annoys me is they (mostly Belkins) have an "Auto" setting which simply does not work.  I put them all on auto and they all chose channel 1 and killed each other.  When they detect something else on the same channel they seem to just shut down, permanently (until I power cycle them).

> 2. Replace the WAPs with ones that run at a higher frequency like the N band
> or the older A  band.  These run at 5ghz instead of the 2.x ghz of the B and
> G's.

I've heard of B (11Mbit) and G (54Mbit) - all but one we have is G 54 Mbit.

We've got about 20 of them and I'm not going to shell out loads of cash just because of these PIRs.  They were always fine with the old PIRS, so it's up to the builders to fix the problem they have caused.  I just want to make sure it is actually caused by the PIRs.

> 3. Have the PIRs moved to a more stategic location that won't get in the way
> of the WLAN.

Difficult.  They could go into another corner of the room, but when the room is an office with 3 or 4 people using wireless laptops on desks throughout the room......

-- 
http://www.petersparrots.com    http://www.insanevideoclips.com    http://www.petersphotos.com

For Sale: Parachute. Only used once, never opened, small stain.

On Fri, 30 Jan 2009 19:37:05 -0000, Lem <lemp40@unknownhost> wrote:

> Peter Hucker wrote:
>> We have a wireless network at work which appears to have gone downhill since the workmen installed PIRs for the burglar alarm.  One of them in particular appears to cause dropped packets the closer a laptop is to it.  Is this possible??  It's not a wireless PIR as far as I know, as I can see some leftover cable he was using which is a multicore (about 10 cores) type similar to phone systems, so I assume this is for the signal aswell as power.  The person in that office swears blind that there were absolutely no problems until the PIR was installed above her desk, and now when I check, about 60% of the packets are being dropped.  Moving her laptop to the opposite side of the room it drops only 5% of packets.  PIRs used to just pick up infrared of your bodyheat, but I think now they are also motion sensors?  Perhaps this means they are sending out a signal and bouncing it off you?  Perhaps this could interfere with wireless networking?
>>
>
> 1. You have a device on the wall that works with your security system
> but you don't really know what it is.  If it really is a "PIR" then by
> definition, it is a "Passive InfraRed" detector, which means that it
> receives signals but doesn't send them out ("passive").  And yes, a PIR
> is typically used as a motion detector:
> http://en.wikipedia.org/wiki/Passive_infrared_sensor

It looks cheap and cheerful with one red LED coming on when I walk about.  I've seen others (in our temporary huts) with THREE different coloured LEDs that come on seperately when I walk in different directions, which I assume are multi-detection ones.  Those don't cause problems with wireless.

> 2. Just because the installers left some cable behind doesn't mean that
> *all* of the devices they installed are wired to the alarm electronics.
> Very often, a security system installed in an already-built location (as
> compared to one installed during construction) will be a combination of
> wired and wireless detectors.

The building is being completely refurbished (everything except the main supporting walls basically).  The section with the problem is an extension, a completely new building.

> 3. Ask the company that installed the security system. Are some of the
> sensors wireless, and if so, what frequency band do they use?

He wasn't there when I was testing, but he was when the user noticed a problem.  When she asked him if the PIR he'd installed could have caused the problem, he said "don't be rediculous, they don't do that".  I've told the project manager to get him to disconnect it for the time being, so I'll see.

> (AFAIK, if you're in the UK, as suggested by one of the groups you posted to,

Yes, UK.

> wireless security systems are *supposed* to use 868 MHz, but you never
> know). Even if the devices are nominally supposed to use 868 MHz, their
> transmitters may be poorly designed and cause interference in the 2.4GHz
> band of 802.11G.

I once bought a wireless video camera which stated it used 2.4GHz.  That had channel settings and only interfered with wireless if on the same channel as the wireless access point.

-- 
http://www.petersparrots.com    http://www.insanevideoclips.com    http://www.petersphotos.com

Capitalism: Man exploiting man.
Socialism: The reverse.

Peter Hucker wrote:
> On Fri, 30 Jan 2009 19:37:05 -0000, Lem <lemp40@unknownhost> wrote:
> 
>> Peter Hucker wrote:
>>> We have a wireless network at work which appears to have gone downhill since the workmen installed PIRs for the burglar alarm.  One of them in particular appears to cause dropped packets the closer a laptop is to it.  Is this possible??  It's not a wireless PIR as far as I know, as I can see some leftover cable he was using which is a multicore (about 10 cores) type similar to phone systems, so I assume this is for the signal aswell as power.  The person in that office swears blind that there were absolutely no problems until the PIR was installed above her desk, and now when I check, about 60% of the packets are being dropped.  Moving her laptop to the opposite side of the room it drops only 5% of packets.  PIRs used to just pick up infrared of your bodyheat, but I think now they are also motion sensors?  Perhaps this means they are sending out a signal and bouncing it off you?  Perhaps this could interfere with wireless networking?
>>>
>> 1. You have a device on the wall that works with your security system
>> but you don't really know what it is.  If it really is a "PIR" then by
>> definition, it is a "Passive InfraRed" detector, which means that it
>> receives signals but doesn't send them out ("passive").  And yes, a PIR
>> is typically used as a motion detector:
>> http://en.wikipedia.org/wiki/Passive_infrared_sensor
> 
> It looks cheap and cheerful with one red LED coming on when I walk about.  I've seen others (in our temporary huts) with THREE different coloured LEDs that come on seperately when I walk in different directions, which I assume are multi-detection ones.  Those don't cause problems with wireless.
> 
>> 2. Just because the installers left some cable behind doesn't mean that
>> *all* of the devices they installed are wired to the alarm electronics.
>> Very often, a security system installed in an already-built location (as
>> compared to one installed during construction) will be a combination of
>> wired and wireless detectors.
> 
> The building is being completely refurbished (everything except the main supporting walls basically).  The section with the problem is an extension, a completely new building.
> 
>> 3. Ask the company that installed the security system. Are some of the
>> sensors wireless, and if so, what frequency band do they use?
> 
> He wasn't there when I was testing, but he was when the user noticed a problem.  When she asked him if the PIR he'd installed could have caused the problem, he said "don't be rediculous, they don't do that".  I've told the project manager to get him to disconnect it for the time being, so I'll see.
> 
>> (AFAIK, if you're in the UK, as suggested by one of the groups you posted to,
> 
> Yes, UK.
> 
>> wireless security systems are *supposed* to use 868 MHz, but you never
>> know). Even if the devices are nominally supposed to use 868 MHz, their
>> transmitters may be poorly designed and cause interference in the 2.4GHz
>> band of 802.11G.
> 
> I once bought a wireless video camera which stated it used 2.4GHz.  That had channel settings and only interfered with wireless if on the same channel as the wireless access point.
> 

If it is difficult to remove that PIR, then just cover it up with 
something made of iron or copper or tin to present a shield between the 
PIR and the wireless laptops.

-- 
Cheers, Bob

On Fri, 30 Jan 2009 20:14:31 -0000, Bob Willard  wrote:

> Peter Hucker wrote:
>> On Fri, 30 Jan 2009 19:37:05 -0000, Lem <lemp40@unknownhost> wrote:
>>
>>> Peter Hucker wrote:
>>>> We have a wireless network at work which appears to have gone downhill since the workmen installed PIRs for the burglar alarm.  One of them in particular appears to cause dropped packets the closer a laptop is to it.  Is this possible??  It's not a wireless PIR as far as I know, as I can see some leftover cable he was using which is a multicore (about 10 cores) type similar to phone systems, so I assume this is for the signal aswell as power.  The person in that office swears blind that there were absolutely no problems until the PIR was installed above her desk, and now when I check, about 60% of the packets are being dropped.  Moving her laptop to the opposite side of the room it drops only 5% of packets.  PIRs used to just pick up infrared of your bodyheat, but I think now they are also motion sensors?  Perhaps this means they are sending out a signal and bouncing it off you?  Perhaps this could interfere with wireless networking?
>>>>
>>> 1. You have a device on the wall that works with your security system
>>> but you don't really know what it is.  If it really is a "PIR" then by
>>> definition, it is a "Passive InfraRed" detector, which means that it
>>> receives signals but doesn't send them out ("passive").  And yes, a PIR
>>> is typically used as a motion detector:
>>> http://en.wikipedia.org/wiki/Passive_infrared_sensor
>>
>> It looks cheap and cheerful with one red LED coming on when I walk about.  I've seen others (in our temporary huts) with THREE different coloured LEDs that come on seperately when I walk in different directions, which I assume are multi-detection ones.  Those don't cause problems with wireless.
>>
>>> 2. Just because the installers left some cable behind doesn't mean that
>>> *all* of the devices they installed are wired to the alarm electronics.
>>> Very often, a security system installed in an already-built location (as
>>> compared to one installed during construction) will be a combination of
>>> wired and wireless detectors.
>>
>> The building is being completely refurbished (everything except the main supporting walls basically).  The section with the problem is an extension, a completely new building.
>>
>>> 3. Ask the company that installed the security system. Are some of the
>>> sensors wireless, and if so, what frequency band do they use?
>>
>> He wasn't there when I was testing, but he was when the user noticed a problem.  When she asked him if the PIR he'd installed could have caused the problem, he said "don't be rediculous, they don't do that".  I've told the project manager to get him to disconnect it for the time being, so I'll see.
>>
>>> (AFAIK, if you're in the UK, as suggested by one of the groups you posted to,
>>
>> Yes, UK.
>>
>>> wireless security systems are *supposed* to use 868 MHz, but you never
>>> know). Even if the devices are nominally supposed to use 868 MHz, their
>>> transmitters may be poorly designed and cause interference in the 2.4GHz
>>> band of 802.11G.
>>
>> I once bought a wireless video camera which stated it used 2.4GHz.  That had channel settings and only interfered with wireless if on the same channel as the wireless access point.
>>
>
> If it is difficult to remove that PIR, then just cover it up with
> something made of iron or copper or tin to present a shield between the
> PIR and the wireless laptops.

Aha!  Wish I'd thought of that!  So it has to be iron copper or tin?  Not just any metal?  The first metal thing I can think of that would be to hand is the lid of a tin of chocolates.  Cadbury's Roses I think, not sure what they use.

-- 
http://www.petersparrots.com    http://www.insanevideoclips.com    http://www.petersphotos.com

             (\
              \)
         ,____/')
         ( __ /
         (/  \)

"Peter Hucker"  wrote in message 
news:op.uok42atv4buhsv@fx62.mshome.net...
> I tend to have just enough WAPs to cover every area, and have found that 
> if they are close, I
> need a difference of only TWO channels (eg use channel 3 and 5), and if 
> they are only just visible
> from one point, then a gap of 1 is enough (eg using channel 4 and 5).

They may seem to work but you can still loose signal.  You are loosing the 
signal "width" because the overlapped part is "lost", or more accuartely, 
"destroyed".  The width of the signal takes up more than one channel.  They 
need to be separated by 5.

----Channel Options in overlaping areas----
Single WAP = any channel
Two WAPs = 1,6  or  2,7  or  3,8  or  4,9  or  5,10 or 6,11
Three WAPs = 1,6,11   This is the only option, no other options
Four WAPs = none available for 4 WAPs unless using roaming

>
> What annoys me is they (mostly Belkins) have an "Auto" setting which 
> simply does not work.  I
> put them all on auto and they all chose channel 1 and killed each other. 
> When they detect
> something else on the same channel they seem to just shut down, 
> permanently (until I power
> cycle them).

Home user products,.....home user quality.

Home-User WAPS = $50 - $80
Commercial quality WAPS = $200 - $1500 (and maybe more)

>> 2. Replace the WAPs with ones that run at a higher frequency like the N 
>> band
>> or the older A  band.  These run at 5ghz instead of the 2.x ghz of the B 
>> and
>> G's.
>
> I've heard of B (11Mbit) and G (54Mbit) - all but one we have is G 54 
> Mbit.

I'm not talking about the IP thoughtput speed,...I'm talking about the 
frequency Band of the radio signal.

> PIRs.  They were always fine with the old PIRS, so it's up to the builders 
> to fix the problem they
> have caused.  I just want to make sure it is actually caused by the PIRs.

Kill the power to the PIR,...if the WAP starts acting better, ..then it was 
the PIR.
Contact the vendor of the PIRs.  Maybe they have adjustments that can be 
made with the PIRs.

-- 
Phillip Windell
www.wandtv.com

The views expressed, are my own and not those of my employer, or Microsoft,
or anyone else associated with me, including my cats.
-----------------------------------------------------

Phillip Windell wrote:
> "Peter Hucker"  wrote in message 
> news:op.uok42atv4buhsv@fx62.mshome.net...
>> I tend to have just enough WAPs to cover every area, and have found that 
>> if they are close, I
>> need a difference of only TWO channels (eg use channel 3 and 5), and if 
>> they are only just visible
>> from one point, then a gap of 1 is enough (eg using channel 4 and 5).
> 
> They may seem to work but you can still loose signal.  You are loosing the 
> signal "width" because the overlapped part is "lost", or more accuartely, 
> "destroyed".  The width of the signal takes up more than one channel.  They 
> need to be separated by 5.
> 
> ----Channel Options in overlaping areas----
> Single WAP = any channel
> Two WAPs = 1,6  or  2,7  or  3,8  or  4,9  or  5,10 or 6,11
> Three WAPs = 1,6,11   This is the only option, no other options

This being "uk.comp.   ", what's wrong with 7,12 and 8,13
  2,7,12 and 3,8,13 ?

> Four WAPs = none available for 4 WAPs unless using roaming
> 

-- 
PeeGee

"Nothing should be able to load itself onto a computer without the
knowledge or consent of the computer user. Software should also be able
to be removed from a computer easily."
Peter Cullen, Microsoft Chief Privacy Strategist (Computing 18 Aug 05)

Peter Hucker wrote:
> On Fri, 30 Jan 2009 20:14:31 -0000, Bob Willard  wrote:
> 
>> Peter Hucker wrote:
>>> On Fri, 30 Jan 2009 19:37:05 -0000, Lem <lemp40@unknownhost> wrote:
>>>
>>>> Peter Hucker wrote:
>>>>> We have a wireless network at work which appears to have gone downhill since the workmen installed PIRs for the burglar alarm.  One of them in particular appears to cause dropped packets the closer a laptop is to it.  Is this possible??  It's not a wireless PIR as far as I know, as I can see some leftover cable he was using which is a multicore (about 10 cores) type similar to phone systems, so I assume this is for the signal aswell as power.  The person in that office swears blind that there were absolutely no problems until the PIR was installed above her desk, and now when I check, about 60% of the packets are being dropped.  Moving her laptop to the opposite side of the room it drops only 5% of packets.  PIRs used to just pick up infrared of your bodyheat, but I think now they are also motion sensors?  Perhaps this means they are sending out a signal and bouncing it off you?  Perhaps this could interfere with wireless networking?
>>>>>
>>>> 1. You have a device on the wall that works with your security system
>>>> but you don't really know what it is.  If it really is a "PIR" then by
>>>> definition, it is a "Passive InfraRed" detector, which means that it
>>>> receives signals but doesn't send them out ("passive").  And yes, a PIR
>>>> is typically used as a motion detector:
>>>> http://en.wikipedia.org/wiki/Passive_infrared_sensor
>>> It looks cheap and cheerful with one red LED coming on when I walk about.  I've seen others (in our temporary huts) with THREE different coloured LEDs that come on seperately when I walk in different directions, which I assume are multi-detection ones.  Those don't cause problems with wireless.
>>>
>>>> 2. Just because the installers left some cable behind doesn't mean that
>>>> *all* of the devices they installed are wired to the alarm electronics.
>>>> Very often, a security system installed in an already-built location (as
>>>> compared to one installed during construction) will be a combination of
>>>> wired and wireless detectors.
>>> The building is being completely refurbished (everything except the main supporting walls basically).  The section with the problem is an extension, a completely new building.
>>>
>>>> 3. Ask the company that installed the security system. Are some of the
>>>> sensors wireless, and if so, what frequency band do they use?
>>> He wasn't there when I was testing, but he was when the user noticed a problem.  When she asked him if the PIR he'd installed could have caused the problem, he said "don't be rediculous, they don't do that".  I've told the project manager to get him to disconnect it for the time being, so I'll see.
>>>
>>>> (AFAIK, if you're in the UK, as suggested by one of the groups you posted to,
>>> Yes, UK.
>>>
>>>> wireless security systems are *supposed* to use 868 MHz, but you never
>>>> know). Even if the devices are nominally supposed to use 868 MHz, their
>>>> transmitters may be poorly designed and cause interference in the 2.4GHz
>>>> band of 802.11G.
>>> I once bought a wireless video camera which stated it used 2.4GHz.  That had channel settings and only interfered with wireless if on the same channel as the wireless access point.
>>>
>> If it is difficult to remove that PIR, then just cover it up with
>> something made of iron or copper or tin to present a shield between the
>> PIR and the wireless laptops.
> 
> Aha!  Wish I'd thought of that!  So it has to be iron copper or tin?  Not just any metal?  The first metal thing I can think of that would be to hand is the lid of a tin of chocolates.  Cadbury's Roses I think, not sure what they use.
> 
Covering the sensor with the Cadbury's lid (mainly, the shield needs to 
be made of an electrically conductive material; copper works best 
(unless you want to use silver); aluminum foil would probably work just 
as well) may help your wifi problem, but it will also make it rather 
useless for the security system.  If you can find the main control box 
for the security system, perhaps there is make/model info there that 
will help you determine if some of its sensors are wireless and if so, 
on what frequency.

I've also seen 2.4GHz security cams, but from a quick Google search, it 
seemed that the wireless sensors used in UK security systems were all 
supposed to be 868 MHz. I don't know how to reconcile those facts (I'm 
neither in the UK nor particularly knowledgeable about security systems).

-- 
Lem -- MS-MVP

To the moon and back with 2K words of RAM and 36K words of ROM.
http://en.wikipedia.org/wiki/Apollo_Guidance_Computer
http://history.nasa.gov/afj/compessay.htm

On Fri, 30 Jan 2009 21:14:02 -0000, PeeGee  wrote:

> Phillip Windell wrote:
>> "Peter Hucker"  wrote in message
>> news:op.uok42atv4buhsv@fx62.mshome.net...
>>> I tend to have just enough WAPs to cover every area, and have found that
>>> if they are close, I
>>> need a difference of only TWO channels (eg use channel 3 and 5), and if
>>> they are only just visible
>>> from one point, then a gap of 1 is enough (eg using channel 4 and 5).
>>
>> They may seem to work but you can still loose signal.  You are loosing the
>> signal "width" because the overlapped part is "lost", or more accuartely,
>> "destroyed".  The width of the signal takes up more than one channel.  They
>> need to be separated by 5.
>>
>> ----Channel Options in overlaping areas----
>> Single WAP = any channel
>> Two WAPs = 1,6  or  2,7  or  3,8  or  4,9  or  5,10 or 6,11
>> Three WAPs = 1,6,11   This is the only option, no other options
>
> This being "uk.comp.   ", what's wrong with 7,12 and 8,13
>   2,7,12 and 3,8,13 ?

I assume you're referring to his lack of channel 12 and 13.  Does only the UK do 12 and 13?  Older laptops (specifically Dell Latitude C510s) only pick up up to channel 11 (they're B (11Mbit) NICs).  The newer ones all do 12 and 13 also (54Mbit G Nics).

-- 
http://www.petersparrots.com    http://www.insanevideoclips.com    http://www.petersphotos.com

While taking down the vitals for a soon-to-be mom, I asked how much she weighed.
"I really don't know," she said.
"Well, more or less," I prompted.
"More, I guess," she answered sadly.

On Fri, 30 Jan 2009 20:58:10 -0000, Phillip Windell  wrote:

>
> "Peter Hucker"  wrote in message
> news:op.uok42atv4buhsv@fx62.mshome.net...
>> I tend to have just enough WAPs to cover every area, and have found that
>> if they are close, I
>> need a difference of only TWO channels (eg use channel 3 and 5), and if
>> they are only just visible
>> from one point, then a gap of 1 is enough (eg using channel 4 and 5).
>
> They may seem to work but you can still loose signal.  You are loosing the
> signal "width" because the overlapped part is "lost", or more accuartely,
> "destroyed".  The width of the signal takes up more than one channel.  They
> need to be separated by 5.

Well I've always had them give a high speed connection.  I do try to keep them far apoart as possible, but there are usually some channels that simply won't work (other buildings nearby using WAPs? - someone even suggested the nearby airport's collision detection!) and with a weird shaped building there are often quite a few overlaps.  Plus areas with people using the B NICs are limited to channels 1-11.

> ----Channel Options in overlaping areas----
> Single WAP = any channel
> Two WAPs = 1,6  or  2,7  or  3,8  or  4,9  or  5,10 or 6,11
> Three WAPs = 1,6,11   This is the only option, no other options
> Four WAPs = none available for 4 WAPs unless using roaming
>
>>
>> What annoys me is they (mostly Belkins) have an "Auto" setting which
>> simply does not work.  I
>> put them all on auto and they all chose channel 1 and killed each other.
>> When they detect
>> something else on the same channel they seem to just shut down,
>> permanently (until I power
>> cycle them).
>
> Home user products,.....home user quality.
>
> Home-User WAPS = $50 - $80
> Commercial quality WAPS = $200 - $1500 (and maybe more)

Hmph.  They don't state they won't work if there are more than one.  And why say "automatic" when it just doesn't?  In fact the slightly more expensive Cisco one we have is a right bugger to get going.  I hate Cisco stuff.

>>> 2. Replace the WAPs with ones that run at a higher frequency like the N
>>> band
>>> or the older A  band.  These run at 5ghz instead of the 2.x ghz of the B
>>> and
>>> G's.
>>
>> I've heard of B (11Mbit) and G (54Mbit) - all but one we have is G 54
>> Mbit.
>
> I'm not talking about the IP thoughtput speed,...I'm talking about the
> frequency Band of the radio signal.

I know.  Aren't B and G different frequency bands too?  If I get ones on a different frequency, surely the NICs on the laptops won't work anymore?  They are designed for G are they not, which is 2.4GHz.

>> PIRs.  They were always fine with the old PIRS, so it's up to the builders
>> to fix the problem they
>> have caused.  I just want to make sure it is actually caused by the PIRs.
>
> Kill the power to the PIR,...if the WAP starts acting better, ..then it was
> the PIR.
> Contact the vendor of the PIRs.  Maybe they have adjustments that can be
> made with the PIRs.

Maybe they are put in to detect laptop use at night ;-)

-- 
http://www.petersparrots.com    http://www.insanevideoclips.com    http://www.petersphotos.com

          _..--""""""""""--.._
       .'`       ______       `'.
    __/     _.-;"      ";-._     \
   (("|     || '--------' ||     |
    ))\_,.-;`   .-""""-.   `;-.,_/
   ((      |  .'  .==.  '.  |
    ))     | /  /` __ `\  \ |
   ((      | | |  (__)  | | |
    ))   _.| \  \      /  / |
   ((   /.-|  '. `'=='` .'  |
    \'-'/  |    '-....-'    |
     `"`   |'-..________..-'|
           |                |
           '-..__________..-'

"PeeGee"  wrote in message 
news:glvqir$s0g$1@news.motzarella.org...
>> ----Channel Options in overlaping areas----
>> Single WAP = any channel
>> Two WAPs = 1,6  or  2,7  or  3,8  or  4,9  or  5,10 or 6,11
>> Three WAPs = 1,6,11   This is the only option, no other options
>
> This being "uk.comp.   ", what's wrong with 7,12 and 8,13
>  2,7,12 and 3,8,13 ?

Ah, yea.  Sorry, I was thinking in a US context.

-- 
Phillip Windell
www.wandtv.com

The views expressed, are my own and not those of my employer, or Microsoft,
or anyone else associated with me, including my cats.
-----------------------------------------------------

On Fri, 30 Jan 2009 21:14:58 -0000, Lem <lemp40@unknownhost> wrote:

> Peter Hucker wrote:
>> On Fri, 30 Jan 2009 20:14:31 -0000, Bob Willard  wrote:
>>
>>> Peter Hucker wrote:
>>>> On Fri, 30 Jan 2009 19:37:05 -0000, Lem <lemp40@unknownhost> wrote:
>>>>
>>>>> Peter Hucker wrote:
>>>>>> We have a wireless network at work which appears to have gone downhill since the workmen installed PIRs for the burglar alarm.  One of them in particular appears to cause dropped packets the closer a laptop is to it.  Is this possible??  It's not a wireless PIR as far as I know, as I can see some leftover cable he was using which is a multicore (about 10 cores) type similar to phone systems, so I assume this is for the signal aswell as power.  The person in that office swears blind that there were absolutely no problems until the PIR was installed above her desk, and now when I check, about 60% of the packets are being dropped.  Moving her laptop to the opposite side of the room it drops only 5% of packets.  PIRs used to just pick up infrared of your bodyheat, but I think now they are also motion sensors?  Perhaps this means they are sending out a signal and bouncing it off you?  Perhaps this could interfere with wireless networking?
>>>>>>
>>>>> 1. You have a device on the wall that works with your security system
>>>>> but you don't really know what it is.  If it really is a "PIR" then by
>>>>> definition, it is a "Passive InfraRed" detector, which means that it
>>>>> receives signals but doesn't send them out ("passive").  And yes, a PIR
>>>>> is typically used as a motion detector:
>>>>> http://en.wikipedia.org/wiki/Passive_infrared_sensor
>>>> It looks cheap and cheerful with one red LED coming on when I walk about.  I've seen others (in our temporary huts) with THREE different coloured LEDs that come on seperately when I walk in different directions, which I assume are multi-detection ones.  Those don't cause problems with wireless.
>>>>
>>>>> 2. Just because the installers left some cable behind doesn't mean that
>>>>> *all* of the devices they installed are wired to the alarm electronics.
>>>>> Very often, a security system installed in an already-built location (as
>>>>> compared to one installed during construction) will be a combination of
>>>>> wired and wireless detectors.
>>>> The building is being completely refurbished (everything except the main supporting walls basically).  The section with the problem is an extension, a completely new building.
>>>>
>>>>> 3. Ask the company that installed the security system. Are some of the
>>>>> sensors wireless, and if so, what frequency band do they use?
>>>> He wasn't there when I was testing, but he was when the user noticed a problem.  When she asked him if the PIR he'd installed could have caused the problem, he said "don't be rediculous, they don't do that".  I've told the project manager to get him to disconnect it for the time being, so I'll see.
>>>>
>>>>> (AFAIK, if you're in the UK, as suggested by one of the groups you posted to,
>>>> Yes, UK.
>>>>
>>>>> wireless security systems are *supposed* to use 868 MHz, but you never
>>>>> know). Even if the devices are nominally supposed to use 868 MHz, their
>>>>> transmitters may be poorly designed and cause interference in the 2.4GHz
>>>>> band of 802.11G.
>>>> I once bought a wireless video camera which stated it used 2.4GHz.  That had channel settings and only interfered with wireless if on the same channel as the wireless access point.
>>>>
>>> If it is difficult to remove that PIR, then just cover it up with
>>> something made of iron or copper or tin to present a shield between the
>>> PIR and the wireless laptops.
>>
>> Aha!  Wish I'd thought of that!  So it has to be iron copper or tin?  Not just any metal?  The first metal thing I can think of that would be to hand is the lid of a tin of chocolates.  Cadbury's Roses I think, not sure what they use.
>>
> Covering the sensor with the Cadbury's lid (mainly, the shield needs to
> be made of an electrically conductive material; copper works best
> (unless you want to use silver); aluminum foil would probably work just
> as well) may help your wifi problem, but it will also make it rather
> useless for the security system.  If you can find the main control box
> for the security system, perhaps there is make/model info there that
> will help you determine if some of its sensors are wireless and if so,
> on what frequency.

I don't care if I render the security system useless.  If I can prove it's causing a problem, it's up to the contractors to fix it.  My wireless was there first!

I bet the girls in the office might object to tin lids in the corner of their rooms though.

> I've also seen 2.4GHz security cams, but from a quick Google search, it
> seemed that the wireless sensors used in UK security systems were all
> supposed to be 868 MHz. I don't know how to reconcile those facts (I'm
> neither in the UK nor particularly knowledgeable about security systems).

Cameras transmit a video feed, and presumably need a lot more bandwidth than a PIR which is saying on or off.  So perhaps they use different bands.


-- 
http://www.petersparrots.com    http://www.insanevideoclips.com    http://www.petersphotos.com

Why do they call it a TV set when you only get one?

"Peter Hucker"  wrote in message 
news:op.uok9jzr24buhsv@fx62.mshome.net...
>> This being "uk.comp.   ", what's wrong with 7,12 and 8,13
>>   2,7,12 and 3,8,13 ?
>
> I assume you're referring to his lack of channel 12 and 13.  Does only the 
> UK do 12 and 13?

Yes, I believe that is the case.  We have too much "stuff" flying around in 
the air over here, so in some situations we don't have as much available for 
certain things.  I think some of that stuff is going to get shifted around 
some more after all the TV Stations switch from analog to digital which is 
going to free up some room in some places  (BTW - we are an NBC Affiliated 
TV Station).


-- 
Phillip Windell
www.wandtv.com

The views expressed, are my own and not those of my employer, or Microsoft,
or anyone else associated with me, including my cats.
-----------------------------------------------------

On Fri, 30 Jan 2009 21:33:57 -0000, Phillip Windell  wrote:

>
> "Peter Hucker"  wrote in message
> news:op.uok9jzr24buhsv@fx62.mshome.net...
>>> This being "uk.comp.   ", what's wrong with 7,12 and 8,13
>>>   2,7,12 and 3,8,13 ?
>>
>> I assume you're referring to his lack of channel 12 and 13.  Does only the
>> UK do 12 and 13?
>
> Yes, I believe that is the case.  We have too much "stuff" flying around in
> the air over here, so in some situations we don't have as much available for
> certain things.  I think some of that stuff is going to get shifted around
> some more after all the TV Stations switch from analog to digital which is
> going to free up some room in some places  (BTW - we are an NBC Affiliated
> TV Station).

Weird, I thought WAPS and NICs could be taken between countries and just work?  If all the channels are different....

-- 
http://www.petersparrots.com    http://www.insanevideoclips.com    http://www.petersphotos.com

Hit the button marked 'STOP' with remaining hand.

"Peter Hucker"  wrote in message 
news:op.uok9rta54buhsv@fx62.mshome.net...
> Hmph.  They don't state they won't work if there are more than one.  And 
> why say "automatic" when it just doesn't?  In fact the slightly more 
> expensive Cisco one we have is a right bugger to get going.  I hate Cisco 
> stuff.
>

Yes, I've found Cisco WAPs to be a real pain to setup too.  In fact I don't 
even remember how to do them without picking through all their config 
"pages" again.

> I know.  Aren't B and G different frequency bands too?  If I get ones on a 
> different frequency, surely the NICs on the laptops won't work anymore? 
> They are designed for G are they not, which is 2.4GHz.
>

I think the "B" and the "G" has something more to do with the Encoding in 
the signal, with G being "backward compatible" with B so a G WAP can still 
work with a B Nic.  But both B and G are 2.4GHz,.  The A is 5GHz and I think 
N can do both (?).

> Maybe they are put in to detect laptop use at night ;-)

<hehe>,..well, I'd ask them and see what they think about all this.  Surely 
they have run into something like this before.

-- 
Phillip Windell
www.wandtv.com

The views expressed, are my own and not those of my employer, or Microsoft,
or anyone else associated with me, including my cats.
-----------------------------------------------------

"Peter Hucker"  wrote in message 
news:op.uolaicah4buhsv@fx62.mshome.net...

> Weird, I thought WAPS and NICs could be taken between countries and just 
> work?  If all the channels are different....

Well,...kinda,...sorta,....maybe,...a little.  The individual channnels are 
probably the same,...it is the usuable range of channels (1-11 -vs- 1-13) 
that is different.

There are regional differences in electonic equipment.  Heck even TV is 
different,...with analog TV the UK is the PAL standard,..the US uses NTSC. 
I'n not sure with Dgital TV what happens.

-- 
Phillip Windell
www.wandtv.com

The views expressed, are my own and not those of my employer, or Microsoft,
or anyone else associated with me, including my cats.
-----------------------------------------------------

On Fri, 30 Jan 2009 21:42:21 -0000, Phillip Windell  wrote:

> "Peter Hucker"  wrote in message
> news:op.uok9rta54buhsv@fx62.mshome.net...
>> Hmph.  They don't state they won't work if there are more than one.  And
>> why say "automatic" when it just doesn't?  In fact the slightly more
>> expensive Cisco one we have is a right bugger to get going.  I hate Cisco
>> stuff.
>>
>
> Yes, I've found Cisco WAPs to be a real pain to setup too.  In fact I don't
> even remember how to do them without picking through all their config
> "pages" again.

I almost got it working, then stupidly pressed the auto setup button on the front, which promptly reset it with stupid settings causing it to be very hard to get hold of.  I always end up in a catch 22 situation, I'm trying to program an IP adress of the WAP but I need to know the IP to get to it!

>> I know.  Aren't B and G different frequency bands too?  If I get ones on a
>> different frequency, surely the NICs on the laptops won't work anymore?
>> They are designed for G are they not, which is 2.4GHz.
>>
>
> I think the "B" and the "G" has something more to do with the Encoding in
> the signal, with G being "backward compatible" with B so a G WAP can still
> work with a B Nic.  But both B and G are 2.4GHz,.  The A is 5GHz and I think
> N can do both (?).

So I'm assuming to use 5Ghz I'd need to have different NICs?  Or maybe all recent ones can do 5GHz?  We've got a few that are 11Mbit, probably those are too old to change frequency.

>> Maybe they are put in to detect laptop use at night ;-)
>
> <hehe>,..well, I'd ask them and see what they think about all this.  Surely
> they have run into something like this before.

Oh I dunno, we've got cheap labour from foreign countries.....  The electricians have caused three fires and blown up £3000 of computer equipment so far.  Ever seen what happens to power supplies in computers when you connect two phases instead of phase and neutral to a socket circuit?  415V is a lot more than 230V.  To be fair I suppose they got confused with the mixture of British and EU wiring we've got till the rewiring is complete.  I believe a black wire is neutral in one set of colours and a phase in the other set.

-- 
http://www.petersparrots.com    http://www.insanevideoclips.com    http://www.petersphotos.com

Whats the fastest thing in Wales?
A virgin sheep.

On Fri, 30 Jan 2009 21:49:12 -0000, Phillip Windell  wrote:

> "Peter Hucker"  wrote in message
> news:op.uolaicah4buhsv@fx62.mshome.net...
>
>> Weird, I thought WAPS and NICs could be taken between countries and just
>> work?  If all the channels are different....
>
> Well,...kinda,...sorta,....maybe,...a little.  The individual channnels are
> probably the same,...it is the usuable range of channels (1-11 -vs- 1-13)
> that is different.

Ah I suppose the laptops would be fine, they just use whatever they find being transmitted.  But if I brought my WAP over there on channel 13 I'd have the authorities hunting me down!

> There are regional differences in electonic equipment.  Heck even TV is
> different,...with analog TV the UK is the PAL standard,..the US uses NTSC.
> I'n not sure with Dgital TV what happens.

One would hope they've taken the opportunity to make it compatible.....

-- 
http://www.petersparrots.com    http://www.insanevideoclips.com    http://www.petersphotos.com

A lawyer is an expert on justice in much the same way your average hooker is an expert on love.

Phillip Windell wrote:
> "PeeGee"  wrote in message 
> news:glvqir$s0g$1@news.motzarella.org...
>>> ----Channel Options in overlaping areas----
>>> Single WAP = any channel
>>> Two WAPs = 1,6  or  2,7  or  3,8  or  4,9  or  5,10 or 6,11
>>> Three WAPs = 1,6,11   This is the only option, no other options
>> This being "uk.comp.   ", what's wrong with 7,12 and 8,13
>>  2,7,12 and 3,8,13 ?
> 
> Ah, yea.  Sorry, I was thinking in a US context.
> 

...and I missed the other groups :-(

-- 
PeeGee

"Nothing should be able to load itself onto a computer without the
knowledge or consent of the computer user. Software should also be able
to be removed from a computer easily."
Peter Cullen, Microsoft Chief Privacy Strategist (Computing 18 Aug 05)

Phillip Windell wrote:
> "Peter Hucker"  wrote in message 
> news:op.uolaicah4buhsv@fx62.mshome.net...
> 
>> Weird, I thought WAPS and NICs could be taken between countries and just 
>> work?  If all the channels are different....
> 
> Well,...kinda,...sorta,....maybe,...a little.  The individual channnels are 
> probably the same,...it is the usuable range of channels (1-11 -vs- 1-13) 
> that is different.

802.11 allows 1-13 I believe, though some countries have added a channel
 14 while others (mainly continental America) disallow 12 and 13.

> 
> There are regional differences in electonic equipment.  Heck even TV is 
> different,...with analog TV the UK is the PAL standard,..the US uses NTSC. 
> I'n not sure with Dgital TV what happens.
> 


-- 
PeeGee

"Nothing should be able to load itself onto a computer without the
knowledge or consent of the computer user. Software should also be able
to be removed from a computer easily."
Peter Cullen, Microsoft Chief Privacy Strategist (Computing 18 Aug 05)

Peter Hucker wrote:
> We have a wireless network at work which appears to have gone downhill since the workmen installed PIRs for the burglar alarm.  One of them in particular appears to cause dropped packets the closer a laptop is to it.  Is this possible??  It's not a wireless PIR as far as I know, as I can see some leftover cable he was using which is a multicore (about 10 cores) type similar to phone systems, so I assume this is for the signal aswell as power.  The person in that office swears blind that there were absolutely no problems until the PIR was installed above her desk, and now when I check, about 60% of the packets are being dropped.  Moving her laptop to the opposite side of the room it drops only 5% of packets.  PIRs used to just pick up infrared of your bodyheat, but I think now they are also motion sensors?  Perhaps this means they are sending out a signal and bouncing it off you?  Perhaps this could interfere with wireless networking?
> 

If the remedies suggested in the other post don't work consider changing 
to the homeplug system.

Geoff Lane

In message , Peter Hucker 
 writes
>We have a wireless network at work which appears to have gone downhill 
>since the workmen installed PIRs for the burglar alarm.  One of them in 
>particular appears to cause dropped packets the closer a laptop is to 
>it.  Is this possible??  It's not a wireless PIR as far as I know, as I 
>can see some leftover cable he was using which is a multicore (about 10 
>cores) type similar to phone systems, so I assume this is for the 
>signal aswell as power.
They will likely be 'dual-tech' detectors, they use RADAR and PIR to 
detect intruders and only when both detect movement is the alarm 
triggered. It's to prevent falsing, the combination of both types is a 
quite neat solution to draughty rooms or rooms which have RADAR 
transparent walls.

Don't know what band the RADAR usually uses but it would not surprise me 
in the slightest if they were 2.4GHz or some frequency that has 
harmonics in the 2.4GHz range.
>d that there were absolutely no problems until the PIR was installed 
>above her desk, and now when I check, about 60% of the packets are 
>being dropped.  Moving her laptop to the opposite side of the room it 
>drops only 5% of packets.  PIRs used to just pick up infrared of your 
>bodyheat, but I think now they are also motion sensors?  Perhaps this 
>means they are sending out a signal and bouncing it off you?  Perhaps 
>this could interfere with wireless networking?
>

-- 
Clint Sharp

On Sat, 31 Jan 2009 14:30:24 -0000, Geoff Lane  wrote:

> Peter Hucker wrote:
>> We have a wireless network at work which appears to have gone downhill since the workmen installed PIRs for the burglar alarm.  One of them in particular appears to cause dropped packets the closer a laptop is to it.  Is this possible??  It's not a wireless PIR as far as I know, as I can see some leftover cable he was using which is a multicore (about 10 cores) type similar to phone systems, so I assume this is for the signal aswell as power.  The person in that office swears blind that there were absolutely no problems until the PIR was installed above her desk, and now when I check, about 60% of the packets are being dropped.  Moving her laptop to the opposite side of the room it drops only 5% of packets.  PIRs used to just pick up infrared of your bodyheat, but I think now they are also motion sensors?  Perhaps this means they are sending out a signal and bouncing it off you?  Perhaps this could interfere with wireless networking?
>>
>
> If the remedies suggested in the other post don't work consider changing
> to the homeplug system.

Sorted anyway, but what is homeplug?


-- 
http://www.petersparrots.com    http://www.insanevideoclips.com    http://www.petersphotos.com

During her annual checkup, the well-constructed miss was asked to disrobe and climb onto the examining table.
"Doctor," she replied shyly, "I just can't undress in front of you."
"All right," said the physician, "I'll flick off the lights. You undress and tell me when you're through."
In a few moments, her voice rang out in the darkness: "Doctor, I've undressed. What shall I do with my clothes?"
"Put them on the chair, on top of mine."

On Sat, 31 Jan 2009 21:46:53 -0000, Clint Sharp  wrote:

> In message , Peter Hucker
>  writes
>>We have a wireless network at work which appears to have gone downhill
>>since the workmen installed PIRs for the burglar alarm.  One of them in
>>particular appears to cause dropped packets the closer a laptop is to
>>it.  Is this possible??  It's not a wireless PIR as far as I know, as I
>>can see some leftover cable he was using which is a multicore (about 10
>>cores) type similar to phone systems, so I assume this is for the
>>signal aswell as power.
> They will likely be 'dual-tech' detectors, they use RADAR and PIR to
> detect intruders and only when both detect movement is the alarm
> triggered. It's to prevent falsing, the combination of both types is a
> quite neat solution to draughty rooms or rooms which have RADAR
> transparent walls.
>
> Don't know what band the RADAR usually uses but it would not surprise me
> in the slightest if they were 2.4GHz or some frequency that has
> harmonics in the 2.4GHz range.

Harmonics then.  Only that one detector out of loads of the same model caused a problem.  Perhaps it was oscillating at half the correct frequency, or the harmonics weren't filtered out enough?

-- 
http://www.petersparrots.com    http://www.insanevideoclips.com    http://www.petersphotos.com

Someday we'll look back on all this and plough into a parked car.

"Peter Hucker"  wrote in message 
news:op.uoqtg9b84buhsv@fx62.mshome.net...
>> If the remedies suggested in the other post don't work consider changing
>> to the homeplug system.
>
> Sorted anyway, but what is homeplug?

Ethernet over mains wiring: one device is connected by Ethernet to the 
router and plugged into the mains. Another device is plugged into mains 
wiring some distance away (eg in another room) and connected by Ethernet to 
a PC (or to several nearby PCs via a hub/switch).

It is used as an alternative to wireless for carrying network traffic over a 
distance which it is difficult to span by Cat 5 cable.

You can even connect a wireless access point to a remote Homeplug device to 
create a local wireless network beyond the rnage of a router's own wireless 
access point.

On Mon, 02 Feb 2009 21:18:35 -0000, "Peter Hucker"  wrote:

>Sorted

(snip)

are you going to tell us how it was sorted, and what the problem was?

On Mon, 02 Feb 2009 21:24:39 -0000, Mortimer  wrote:

> "Peter Hucker"  wrote in message
> news:op.uoqtg9b84buhsv@fx62.mshome.net...
>>> If the remedies suggested in the other post don't work consider changing
>>> to the homeplug system.
>>
>> Sorted anyway, but what is homeplug?
>
> Ethernet over mains wiring: one device is connected by Ethernet to the
> router and plugged into the mains. Another device is plugged into mains
> wiring some distance away (eg in another room) and connected by Ethernet to
> a PC (or to several nearby PCs via a hub/switch).
>
> It is used as an alternative to wireless for carrying network traffic over a
> distance which it is difficult to span by Cat 5 cable.
>
> You can even connect a wireless access point to a remote Homeplug device to
> create a local wireless network beyond the rnage of a router's own wireless
> access point.

I see.  no use to use.  We already have cat 5 (well 6) everywhere.  The wireless is just for the convenience of people suing laptops all over the place.

Working fine now I've had the detector replaced and changed the WAP to another channel.

-- 
http://www.petersparrots.com    http://www.insanevideoclips.com    http://www.petersphotos.com

Why do our kids have to take the Iowa Test for Basic Skills? 
Why can't we have a Georgia Test of Basic Skills with questions like,
"Bubba's got three cars and he done traded for two more. How many cement blocks is Bubba gonna need?"

On Tue, 03 Feb 2009 02:04:54 -0000, rebel  wrote:

> On Mon, 02 Feb 2009 21:18:35 -0000, "Peter Hucker"  wrote:
>
>>Sorted
>
> (snip)
>
> are you going to tell us how it was sorted, and what the problem was?

The detector was faulty.  Must have been emitting at a frequency that it shouldn't have, or perhaps too strongly?  The replacement is fine.  The installer was bewildered and had never seen it happen before.


-- 
http://www.petersparrots.com    http://www.insanevideoclips.com    http://www.petersphotos.com

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        NNNNNNNNNNNNNNNN)
        NNNN""NNNNF"4NNN)
        (NN    NN)   (NN
         4N.  .NNL   JN`
          NNNNNN(NNNNN)
          NNNNN  (NNNN)
            "NNNNNNF`
            N.NNNN`N`
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