Re: Help : RF Keyfob blocked on Driveway

["seniorsimon" <simon.ryley@xxxxxxxxxx>]

Can you tell us the brands and models of the cars? It might help to
narrow down the problem.

I can also confirm that wireless doorbells are a known issue for
interference with vehicle RF remotes.

Will the remote work if you hold it right next to the car?  Common
places for car RF receivers are above interior mirror mount, in the
centre of the base of the windscreen, (under the top of the dash)  by
the radio/GPS aerial at the rear of the roof if the car has one, or
under the rear parcel shelf if its a saloon.  Try holding the
transmitter close to those points to see if it will open.

Finally, will the cars start if you open them with the key?

Simon

--- In ukha_d@xxxxxxx, "Ian Davidson" <ian@...> wrote:
>
> Hi
>
> Most keyfobs operate on 433Mhz (I think 433.920 off hand). This is a
> heavily used channel for many things. Has as been mention wireless
> doorbell and also temperature sensors, outside lights with internal
> buzzer etc etc. Any of these items crashing causing the transmitter to
> stay on permanently will cause the issue. Another cause is NOT mobile
> phone masts but masts with UHF transmitters on them, these can be the
> new police tetra masts but also older commercial UHF systems. The
final
> cause can be a local radio amateur using the 70cm band. The last two
> causes are due to the cheap receivers built into the cars, not only do
> they receive there own channel but get de-sensed when a very much
> stronger signal is being transmitted on a nearby channel. I think a
> keyfob is a 10mW device whereby our commercial UHF systems can run 25W
> erp a few Mhz away.
>
> A cheap radio scanner that covers UHF would allow you to find most
> items. Although the devices are digital they still make a noise on the
> scanner and enable you to track it to some degree. In really bad cases
> OFCOM may help although they do not have to as it is an unlicensed
band.
>
> Regards
>
> Ian D.
>
>
>
> -----Original Message-----
> From: ukha_d@xxxxxxx [mailto:ukha_d@xxxxxxx] On Behalf
> Of noughtomate
> Sent: 26 October 2006 15:31
> To: Ian
> Subject: [ukha_d] Help : RF Keyfob blocked on Driveway
>
> Hi,
>
> Hoping you guys might know a thing or two to help me.
>
> Me and the Mrs. Cars are parked on our drive way.
>
> Once/ Twice a month we find that are key fobs to our cars are rendered
> useless. The cars do not respond to open or close using the RF keyfob.
>
> I've eliminated battery and car/fob sync issues and it's abit too co-
> incidental it happends to both of our cars at the same time.
>
> I've spoken to the neighbours about the problem, but they've not
> experienced any issues.
>
> If I park the car on the road, a house or two away, the cars respond
> fine to the keyfob.
>
> I'm convinced there's some kind of RF blocker / interrference in close
> vicinity to the house but I really can't think of what it is.
>
> The only bits of outdoor kit I've recently installed in the past year-
> and-a-half since I've lived there are a Comfort Alarm system (Alarm
> bell faces drive) and a hard-wired CCTV camera which is hardly ever
> on. The Alarm Bell has a luminosity detector which I use to automate
> my lighting.
>
> I know my neighbour has wireless CCTV - I can pick up his signal. That
> aside, I've got the 'usual' RF devices - Harmony 895 (RF switched
> off), baby monitor, Bluetooth keyboard and DECT phone.
>
> But I'm not convinced that these could be causing RF interference.
>
> Could anybody advise on how I could narrow down / fix the problem ?
>
> Do keyfobs work at a particulr frequency range, which could clash with
> appliances ?
>
> I tried a Maplin RF Detector (http://tinyurl.com/y4x69c) , but it
> didn't detect anything.
>
> Any help would be much appreciated.
>
> Many Thanks,
>
> Balraj
>
>
>
>
>
>
>
>
>
> ** Sponsored by http://www.BERBLE.com **
> all the Cool Stuff, in one Place
>





** Sponsored by http://www.BERBLE.com **
all the Cool Stuff, in one Place