Re: newbie needs advice

[-pull@shoot]

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