Re: newbie needs advice

[-pull@shoot]

On Tue, 19 Apr 2005 00:04:03 +0200, -pull@shoot wrote:

>On Mon, 18 Apr 2005 20:51:34 GMT, HamNCheese
><sorry_no_e-mail@xxxxxxxx> wrote:
>
>>The installers all seem to use wireless.  How reliable is this?  I
>>have many doors and windows and wiring them all would be extremely
>>expensive.
>
>Wireless is no longer installed by professionals, its unreliable (deaf
>and dead) when a transmission occur on or near be the system receiver
>frequency.
>Worse, that "muzzling" of the system is not reported.
>
>What type of signals are able to produce RFI (Radio Frequency
>Interference) on Wireless Alarm Systems and will jeopardize they're
>operation?
>RF Transmitters operating:
>- ON the wireless frequency (434 & 868 MHz)
>- Falling in the receiver band pass (sideband rejection is poor)
>- Saturating the receiver input stage (wide band in all systems)
>- Intermodulation (mix of two signals)
>- Harmonics
>- On the IF frequency
>- and more...
>In essence the problems caused by interferences of any kind is the
>fact that by no way two (or more) systems can use simultaneously the
>same frequency.
>
>
>Paul