42. If you like to purchase an alarm system.....

[-pull@shoot]

If you like to purchase an alarm system go WIRED.

Wireless alarm systems are unreliable when there is a Transmitters in
the vicinity operating:
- ON the wireless frequency
- Saturating the receiver
- provoking intermodulation
- having harmonics
- Falling aside in the receiver bandpass
- On the IF frequency
- and more...
In essence the problems caused can be defined as a "Radio Frequency
Interference (RFI)" and is the fact that by no way two (or more)
systems can use simultaneously the same receiver input.
 THIS RFI muzzle and jeopardize completely the normal operation you
expect from an alarm system.

Several pro's admit now that RFI exist and can't be avoided.
 In the same post they say that:
 - in "modern" systems RFI is detected..
 - they had no warning since 20+ Years (they call that experience).
  Question:
     Are those "modern" systems with that marvelous RFI detection
     circuit existing since 20+ years?

WHAT CAN BE CONCLUDED OUT OF THAT?
1. The unproved and manufacturer unsupported RFI detection system
   is inefficient or don't exist;
 OR
2. RFI is NOT ALARMED/WARNED and in that case its easy to say that
   they had no warning since 20+ Years.

This last item (2.) seems the be the trued RFI is NOT WARNED, the
remaining is pro's attempt to sell wireless systems without
scrupulous, financial interest obliges.

Paul