This is really OT.
I have a 206 van (2001) with remote control central locking. The range of
the transmitter seemed to be quite good, at least 15m. Then, one day, I
noticed that the range was very short at home, but still ok when I get to
work. I didn't really think anything of it.
Now I have another car (BMW 530d, 1999) which seems to have the same
problem; low range at home (i.e. the key needs to be right by the car's
window for it to work) but ok elsewhere (except Carrefour in Cherbourg!).
And I have another car (BMW 525tds 1993) which has a decent range
everywhere.
So the question is what can cause this apparent localised interference to
'modern' systems, but not my older car? Are there known interference
problems of this type?
I did switch off the mains to my house suspecting that there was something
here that could cause a problem, but it's not me. I'm going to plot the
range at various places araound where I live. This is beginning to bug me
now.

I think that the modern remote central locking devices use the same
band as digital cordless phones and wireless home networking. This
changed some time in the last ten years.

If my befuddled memory is right that would, perhaps, explain things.

Grumps wrote:

> This is really OT.
> I have a 206 van (2001) with remote control central locking. The
> range of the transmitter seemed to be quite good, at least 15m. Then,
> one day, I noticed that the range was very short at home, but still
> ok when I get to work. I didn't really think anything of it.
> Now I have another car (BMW 530d, 1999) which seems to have the same
> problem; low range at home (i.e. the key needs to be right by the
> car's window for it to work) but ok elsewhere (except Carrefour in
> Cherbourg!). And I have another car (BMW 525tds 1993) which has a
> decent range everywhere.
> So the question is what can cause this apparent localised
> interference to 'modern' systems, but not my older car? Are there
> known interference problems of this type?
> I did switch off the mains to my house suspecting that there was
> something here that could cause a problem, but it's not me. I'm going
> to plot the range at various places araound where I live. This is
> beginning to bug me now.


I used to have a weird problem. Whenever I parked outside Bickley train 
station, near Bromley, my remote central locking wouldn't work, on a 2000 
Vectra. The first time I found it wasn't working, I drove to the local 
Vauxhall dealer, where I promptly found that it was working again.

Doesn't help you in any way, but at least you're not alone!

"Matt Beard"  wrote in message
news:1125406278.649337.252940@o13g2000cwo.googlegroups.com...

> I think that the modern remote central locking devices use the same
> band as digital cordless phones and wireless home networking. This
> changed some time in the last ten years.
>
> If my befuddled memory is right that would, perhaps, explain things.


So every time I stand outside relentlessly trying to get my car unlocked,
someone, somewhere, has a home network having errors? That gives me some
satisfaction (although the RF level of my remote is probably far less power
than those wireless networks). It could even be my own cordless phone!

"Grumps"  wrote in message 
news:3nj25mF1nsjqU1@individual.net...

> This is really OT.
> I have a 206 van (2001) with remote control central locking. The range of
> the transmitter seemed to be quite good, at least 15m. Then, one day, I
> noticed that the range was very short at home, but still ok when I get to
> work. I didn't really think anything of it.
> Now I have another car (BMW 530d, 1999) which seems to have the same
> problem; low range at home (i.e. the key needs to be right by the car's
> window for it to work) but ok elsewhere (except Carrefour in Cherbourg!).
> And I have another car (BMW 525tds 1993) which has a decent range
> everywhere.
> So the question is what can cause this apparent localised interference to
> 'modern' systems, but not my older car? Are there known interference
> problems of this type?
> I did switch off the mains to my house suspecting that there was something
> here that could cause a problem, but it's not me. I'm going to plot the
> range at various places araound where I live. This is beginning to bug me
> now.
>
>

Wireless alarms, my outside thermometer, other stuff operate on the same 
frequency as my car remote (IIRC ~432MHz).
No where near cordless phones or wireless LANs.

But any powerful transmitter could interfere with the low cost receivers 
used in cars.
Hence the cars that wont open at airports.

In article , Matt 
Beard  writes

>I think that the modern remote central locking devices use the same
>band as digital cordless phones and wireless home networking. This
>changed some time in the last ten years.
>
>If my befuddled memory is right that would, perhaps, explain things.
>

It's true that the frequencies used by remote locking transmitters are 
unlicensed and shared by many different types of product, however DECT 
phones and wireless networks are not among them.

The freqs are usually 433MHz or 868MHz. Dect is on 1.8GHz and wifi is 
2.4GHz.

It could be that if there is a wifi or DECT base station in a nearby 
house, the receiver of the car is being saturated by it and can't "hear" 
the signal on the other frequency. This can also happen with cellphone 
base station masts.

-- 
Tim Mitchell

Grumps wrote:

> This is really OT.
> I have a 206 van (2001) with remote control central locking. The range of
> the transmitter seemed to be quite good, at least 15m. Then, one day, I
> noticed that the range was very short at home, but still ok when I get to
> work. I didn't really think anything of it.
> Now I have another car (BMW 530d, 1999) which seems to have the same
> problem; low range at home (i.e. the key needs to be right by the car's
> window for it to work) but ok elsewhere (except Carrefour in Cherbourg!).
> And I have another car (BMW 525tds 1993) which has a decent range
> everywhere.
> So the question is what can cause this apparent localised interference to
> 'modern' systems, but not my older car? Are there known interference
> problems of this type?
> I did switch off the mains to my house suspecting that there was something
> here that could cause a problem, but it's not me. I'm going to plot the
> range at various places araound where I live. This is beginning to bug me
> now.


Search for "tetra central locking site:uk" in Google

MBQ

On Tue, 30 Aug 2005 13:21:50 GMT, "dennis@home"  wrote:


>
>"Grumps"  wrote in message 
>news:3nj25mF1nsjqU1@individual.net...
>> This is really OT.
>> I have a 206 van (2001) with remote control central locking. The range of
>> the transmitter seemed to be quite good, at least 15m. Then, one day, I
>> noticed that the range was very short at home, but still ok when I get to
>> work. I didn't really think anything of it.
>> Now I have another car (BMW 530d, 1999) which seems to have the same
>> problem; low range at home (i.e. the key needs to be right by the car's
>> window for it to work) but ok elsewhere (except Carrefour in Cherbourg!).
>> And I have another car (BMW 525tds 1993) which has a decent range
>> everywhere.
>> So the question is what can cause this apparent localised interference to
>> 'modern' systems, but not my older car? Are there known interference
>> problems of this type?
>> I did switch off the mains to my house suspecting that there was something
>> here that could cause a problem, but it's not me. I'm going to plot the
>> range at various places araound where I live. This is beginning to bug me
>> now.
>>
>>
>Wireless alarms, my outside thermometer, other stuff operate on the same 
>frequency as my car remote (IIRC ~432MHz).
>No where near cordless phones or wireless LANs.
>
>But any powerful transmitter could interfere with the low cost receivers 
>used in cars.
>Hence the cars that wont open at airports. 
>


It is not likely to be another device on the 433 band, as these have limited duty-cycles, i.e. only
transmitting occasionally (unless faulty, or, say, a keyfob at the bottom of a drawer with stuff
piled on it holding the button down, although the battery  would die pretty quickly)  It is far more
likely to be an out-of-band signal that either has a harmonic in the receiver's range, or is just
overloading it.  If it happens all the time then that limits the probably cause to something that is
always on - a nearby cellphone basestation, wireless network or video sender would probably be the
most likely candidates, although interference from an unintentional radiating item that just happens
to be at an unfortunate frequency could also cause problems.

"Grumps"  wrote in message 
news:3nj25mF1nsjqU1@individual.net...

> This is really OT.
> I have a 206 van (2001) with remote control central locking. The range of
> the transmitter seemed to be quite good, at least 15m. Then, one day, I
> noticed that the range was very short at home, but still ok when I get to
> work. I didn't really think anything of it.
> Now I have another car (BMW 530d, 1999) which seems to have the same
> problem; low range at home (i.e. the key needs to be right by the car's
> window for it to work) but ok elsewhere (except Carrefour in Cherbourg!).
> And I have another car (BMW 525tds 1993) which has a decent range
> everywhere.
> So the question is what can cause this apparent localised interference to
> 'modern' systems, but not my older car? Are there known interference
> problems of this type?
> I did switch off the mains to my house suspecting that there was something
> here that could cause a problem, but it's not me. I'm going to plot the
> range at various places araound where I live. This is beginning to bug me
> now.


Mobile phone masts can cause this.  Got one near you?

"Grumps"  wrote in message
news:3nj25mF1nsjqU1@individual.net...

> This is really OT.


I have found that I can increase the range of my VW central locking remote
control by holding the metal keyring end to my head.

I don't know what this does to my brain!

(A point I learnt from the BBC2 Sunday evening motoring programme.)

-- 

Michael Chare

"Spike"  wrote in message
news:3njcfnF1qe8aU1@individual.net...

>
> "Grumps"  wrote in message
> news:3nj25mF1nsjqU1@individual.net...
> > This is really OT.
> > I have a 206 van (2001) with remote control central locking. The range
of
> > the transmitter seemed to be quite good, at least 15m. Then, one day, I
> > noticed that the range was very short at home, but still ok when I get
to
> > work. I didn't really think anything of it.
> > Now I have another car (BMW 530d, 1999) which seems to have the same
> > problem; low range at home (i.e. the key needs to be right by the car's
> > window for it to work) but ok elsewhere (except Carrefour in
Cherbourg!).
> > And I have another car (BMW 525tds 1993) which has a decent range
> > everywhere.
> > So the question is what can cause this apparent localised interference
to
> > 'modern' systems, but not my older car? Are there known interference
> > problems of this type?
> > I did switch off the mains to my house suspecting that there was
something
> > here that could cause a problem, but it's not me. I'm going to plot the
> > range at various places araound where I live. This is beginning to bug
me
> > now.
>
> Mobile phone masts can cause this.  Got one near you?


No.

"Michael Chare"  wrote in message
news:vb-dnR6vpOpp4YneRVnyuQ@pipex.net...

> "Grumps"  wrote in message
> news:3nj25mF1nsjqU1@individual.net...
> > This is really OT.
>
> I have found that I can increase the range of my VW central locking remote
> control by holding the metal keyring end to my head.
>
> I don't know what this does to my brain!
>
> (A point I learnt from the BBC2 Sunday evening motoring programme.)


Yes, that normally works. But not in this case.

> 
> I have found that I can increase the range of my VW central locking
> remote control by holding the metal keyring end to my head.
> 
> I don't know what this does to my brain!
> 
> (A point I learnt from the BBC2 Sunday evening motoring programme.)
> 

"Top Gear"

I'm an absolute anti petrol-head, but I like the prog; it seems the last 
place in this doomridden country where anybody is allowed to have fun.

The method increases the rather short range on my m/cycle alarm by many 
times.

I've found out that handy railings, traffic signs, stink-pipes, etc also 
work well if you have an brains left to worry about

mike

wrote in message
news:1125410324.484438.223540@g14g2000cwa.googlegroups.com...

>
> Grumps wrote:
> > This is really OT.
> > I have a 206 van (2001) with remote control central locking. The range
of
> > the transmitter seemed to be quite good, at least 15m. Then, one day, I
> > noticed that the range was very short at home, but still ok when I get
to
> > work. I didn't really think anything of it.
> > Now I have another car (BMW 530d, 1999) which seems to have the same
> > problem; low range at home (i.e. the key needs to be right by the car's
> > window for it to work) but ok elsewhere (except Carrefour in
Cherbourg!).
> > And I have another car (BMW 525tds 1993) which has a decent range
> > everywhere.
> > So the question is what can cause this apparent localised interference
to
> > 'modern' systems, but not my older car? Are there known interference
> > problems of this type?
> > I did switch off the mains to my house suspecting that there was
something
> > here that could cause a problem, but it's not me. I'm going to plot the
> > range at various places araound where I live. This is beginning to bug
me
> > now.
>
> Search for "tetra central locking site:uk" in Google


Hmm. Sounds like it could be this. So, I'm stuffed then!?

On 30 Aug,  
     "Matt Beard"  wrote:


> I think that the modern remote central locking devices use the same
> band as digital cordless phones and wireless home networking. This
> changed some time in the last ten years.
> 
> If my befuddled memory is right that would, perhaps, explain things.
> 

They often use simple receivers and are around 450MHz, which is populated by
many other users. I notice mine has poor range generally in car parks, and
particularly in the town hall car park, which is adjacent to the police
station and it's communications facilities.

-- 
  B Thumbs
  Change lycos to yahoo to reply

Yes, it seems that my befuddled memory had it the wrong way! They were
all moved into the 433Mhz band. This is frequency surrounded by lots of
military stuff!!

Tim Mitchell  wrote:


>In article , Matt 
>Beard  writes
>>I think that the modern remote central locking devices use the same
>>band as digital cordless phones and wireless home networking. This
>>changed some time in the last ten years.
>>
>>If my befuddled memory is right that would, perhaps, explain things.
>>
>It's true that the frequencies used by remote locking transmitters are 
>unlicensed and shared by many different types of product, however DECT 
>phones and wireless networks are not among them.
>
>The freqs are usually 433MHz or 868MHz. Dect is on 1.8GHz and wifi is 
>2.4GHz.


There were originally two UK "unlicenced" low power allocations in the
400-500Mhz range. I can't recall exactly what the other was (418MHz?)
but only one of the two is now permitted for short duration signals
such as the remotes use.

The other was allocated but only for so many years but its now being
reallocated and used by something else (TETRA PMR I think) hence the
intermittent problems with car remote usage - this might be the 433MHz
or it might be 418MHz.


--

Matt Beard wrote:

> Yes, it seems that my befuddled memory had it the wrong way! They were
> all moved into the 433Mhz band. This is frequency surrounded by lots of
> military stuff!!
> 

Not much military stuff at that frequency, but lots of radio amateurs. 
They use simplex and split frequency working. 433 MHz being the centre 
of activity.

I have 2 Rover 45's and last night I could not lock or un-lock either of 
them, but I do have a radio ham across the road and I know he uses this 
frequency. Half an hour later, they both worked perfectly.

HTH

Dave

Dave  writes:

>Matt Beard wrote:
>> Yes, it seems that my befuddled memory had it the wrong way! They were
>> all moved into the 433Mhz band. This is frequency surrounded by lots of
>> military stuff!!
>> 
>Not much military stuff at that frequency, but lots of radio amateurs. 
>They use simplex and split frequency working. 433 MHz being the centre 
>of activity.
>
>I have 2 Rover 45's and last night I could not lock or un-lock either of 
>them, but I do have a radio ham across the road and I know he uses this 
>frequency.


Ah. 433MHz, aka 70cms.

-- 
       "The road to Paradise is through Intercourse."
        [email me at huge [at] huge [dot] org [dot] uk]

Huge wrote:


> Dave  writes:
> 

>>I have 2 Rover 45's and last night I could not lock or un-lock either of 
>>them, but I do have a radio ham across the road and I know he uses this 
>>frequency.
> 
> 
> Ah. 433MHz, aka 70cms.


Yup, one and the same.

Dave

A radio ham for over 30 years, but I have never stopped myself from 
locking/un-locking my car.

Dave  writes:

>Huge wrote:
>
>> Dave  writes:
>> 
>
>>>I have 2 Rover 45's and last night I could not lock or un-lock either of 
>>>them, but I do have a radio ham across the road and I know he uses this 
>>>frequency.
>> 
>> 
>> Ah. 433MHz, aka 70cms.
>
>Yup, one and the same.
>
>Dave
>
>A radio ham for over 30 years, but I have never stopped myself from 
>locking/un-locking my car.


Ah, but I've crashed the ECU in my Sierra Cosworth and set off assorted
burglar alarms.

-- 
       "The road to Paradise is through Intercourse."
        [email me at huge [at] huge [dot] org [dot] uk]

Dave wrote:


> Matt Beard wrote:
> 
>> Yes, it seems that my befuddled memory had it the wrong way! They were
>> all moved into the 433Mhz band. This is frequency surrounded by lots of
>> military stuff!!
>>
> Not much military stuff at that frequency, but lots of radio amateurs. 
> They use simplex and split frequency working. 433 MHz being the centre 
> of activity.
> 
> I have 2 Rover 45's and last night I could not lock or un-lock either of 
> them, but I do have a radio ham across the road and I know he uses this 
> frequency. Half an hour later, they both worked perfectly.
> 
> HTH
> 
> Dave


Depends on where in the country your located, the MOD is the primary 
user, amateurs secondary, a number of primary user/protected sites have 
active jamming to prevent remote initiation of 'devices'. Central london 
also has a segment issued to commercial PMR with quite high power 
transmitters. A number of car remotes operate on 418 and 458 but most 
are on 433.2 a frequency that was not originally issued to them but 
rather taken by the manufacturers and gained by default, even so a high 
power transmitter (5 watts is high compared with a remote blipper) 
within a few meg will swamp the receiver as most are simple re-gen 
designs, something that will get worse in the future as more frequencies 
are sold off to the highest bidder....

Dave wrote:


> Huge wrote:
> 
>> Dave  writes:
>>
> 
>>> I have 2 Rover 45's and last night I could not lock or un-lock either 
>>> of them, but I do have a radio ham across the road and I know he uses 
>>> this frequency.
>>
>>
>>
>> Ah. 433MHz, aka 70cms.
> 
> 
> Yup, one and the same.
> 
> Dave
> 
> A radio ham for over 30 years, but I have never stopped myself from 
> locking/un-locking my car.


Nor me, thats what the keys are for!

Huge wrote:


> Dave  writes:
> 
>>Huge wrote:
>>
>>
>>>Dave  writes:
>>>
>>
>>>>I have 2 Rover 45's and last night I could not lock or un-lock either of 
>>>>them, but I do have a radio ham across the road and I know he uses this 
>>>>frequency.
>>>
>>>
>>>Ah. 433MHz, aka 70cms.
>>
>>Yup, one and the same.
>>
>>Dave
>>
>>A radio ham for over 30 years, but I have never stopped myself from 
>>locking/un-locking my car.
> 
> 
> Ah, but I've crashed the ECU in my Sierra Cosworth and set off assorted
> burglar alarms.


Before Rover collapsed, I made a point of asking about high power TX's 
fitted to my cars. ( manual stated that it was not advisable) They 
stated thAt they had never encountered a problem. When I said that I 
would be running a tad more than a taxi, they still insisted that it 
would not be a problem.

I have had more problems with an Icom 706 mk2 with separation cable, 
than with the car. The radio locked up on HF (forty), mid conversation  :-(

Burglar alarms don't count  ;-)
They are fair game, like next door's TV/audio systems.

Dave

Badger wrote:


> Dave wrote:
> 
>> Matt Beard wrote:
>>
>>> Yes, it seems that my befuddled memory had it the wrong way! They were
>>> all moved into the 433Mhz band. This is frequency surrounded by lots of
>>> military stuff!!
>>>
>> Not much military stuff at that frequency, but lots of radio amateurs. 
>> They use simplex and split frequency working. 433 MHz being the centre 
>> of activity.
>>
>> I have 2 Rover 45's and last night I could not lock or un-lock either 
>> of them, but I do have a radio ham across the road and I know he uses 
>> this frequency. Half an hour later, they both worked perfectly.
>>
>> HTH
>>
>> Dave
> 
> 
> Depends on where in the country your located,


Preston. Lancs

Not much, if any, military activity here, even though we have BAe 
Systems quite close.

All problems with non car access are due to radio hams. I should know, I 
am one.

Dave

Dave wrote:


> Preston. Lancs
> 
> Not much, if any, military activity here, even though we have BAe 
> Systems quite close.
> 
> All problems with non car access are due to radio hams. I should know, I 
> am one.
> 
> Dave


Listen on 433.2 then, you may hear comms, not just open carriers

Matt wrote:


> The other was allocated but only for so many years but its now being
> reallocated and used by something else (TETRA PMR I think) hence the
> intermittent problems with car remote usage - this might be the 433MHz
> or it might be 418MHz.


TETRA has two frequency bands. 380-400 is used by the emergency services 
(Airwave system by O2) and 410-430 which was allocated to public use. 
The service provider was Dolphin but I believe they may have folded.

-- 
Howard Neil