Re: 46. NEWBEES, external RF transmitters disturb often Wireless Alarm Systems..

[Crash Gordon® <webmaster@xxxxxxxxxxxxxxxxxxxxx>]

Don't "thrust" Beligian either, they can muzzle you and you'll =
neverknowit.



<-pull@shoot> wrote in message =
news:a9b9c19k82gn2fvmvgpaot9ta1qs02v60e@xxxxxxxxxx
|=20
| Don't thrust wireless alarm systems, use wired!!!
|=20
| My wireless alarm system was:
| - "deaf", muzzled for sensor signal reception
|        and
| - "dead" on alarm giving
|  when i used a simple commercial available wireless radio headphone,
| that simple ..
|=20
| Its a well known radio transmission problem called "Radio Frequency
| Interference" (RFI)
| - present at ALL systems (old and new =3D external) but
| - more present than normal in wireless alarm systems due to the low
| power transmitters (10milliWatt) used in the sensors
|  AND
| - the use of shared frequencies (obliged) who have disturbances and
| are unprotected for RFI (see at FCC and/or other country authorities
| for the world frequency band attribution scheme or www.ero.dk for
| official info).
|=20
| What type of signals are able to jeopardize they're operation?
| External RF Transmitters operating:
| - ON the wireless frequency
| - Falling in the receiver band pass
| - On the IF frequency (IF =3D Intermediate Frequency)
| - Intermodulation
| - Saturating the receiver front end circuit
| - Harmonics
| - and more...
| In essence the problems caused by interference is the fact that by no
| way two (or more) systems can use simultaneously the same frequency.
|=20
|  My wireless headphone story showed me "how simple it is" to have the
| operation jeopardized completely by an external transmitter operating
| on the wireless alarm frequency.
|=20
|  This problem is NOT REPORTED by any mean to the owner, realize what
| can happen when you have a wireless FIRE detection system...
|  The system will no longer detect it (same for intruder alarm).
|=20
|=20
| I replaced my Wireless Alarm System with a wired one; the problem is
| solved for me, what about yours?
|=20
|=20
| Some "extra clever pro's" say that the FCC (++) will locate and find
| the disturbing signal.
| 1. Just realize that the local range of the disturbing signal don't
|    allow to locate it at distance.
| 2. That other legal users share the wireless alarm frequency
|    and that they have to find out in that bunch the one whom is
|    disturbing... Good luck.
|=20
| Paul
|=20
|