Re: Wired or Wireless alarm systems?

[Crash Gordon® <NONE@xxxxxxxx>]

This guy's a wacko.

He installed ONE piece of crap wireless system that didn't work, and he =
blames the world.

I've installed HUNDREDS of wireless systems and never had aproblem with =
them. I DID have an RFI problem once and it was with a WIRED system (go =
figure).

Thing is...no one disputes that RFI exists. It does. It but it seems Dr. =
Paulie and his ONE install is more of an expert than people who put them =
in every day. He doesn't really understand the stuff he is =
copying/pasting here...he just is a wacko who wants attention of =
somekind. He's annoying, like a mosquito on a beautiful summer day.


"Mel" <Respond@xxxxxxxxxxxxx> wrote in message =
news:d43eq5$5o3o$1@xxxxxxxxxxxxxxxxxxxx
> My wireless doorbell and wireless garage door opener have worked =
flawlessly=20
> for many years. They respond only when the button is pressed and have =
never=20
> failed to respond. Up on the mountain here, there are four=20
> radio/TV/communications/cell phone towers within 1/4 mile of my home. =
I'd=20
> guess there is a fair amount of RF and yet never a mishap of any sort. =
I'm=20
> currently installing a hybrid hard-wired and wireless system and I =
fully=20
> believe it will work as just well as the doorbell and garage door =
opener.
>=20
> Bob
>=20
>=20
> "Crash Gordon=AE" <NONE@xxxxxxxx> wrote in message=20
> news:uEa9e.17$UP5.640@xxxxxxxxxxxxxxxxxx
> sheesh, you're MUCH worse than a nagging wife.
>=20
>=20
> <-pull@shoot> wrote in message=20
> news:o2da61p84i0p5qe5fn8ujjveor1uskqgea@xxxxxxxxxx
> >
> > What is the basic difference between wired and wireless alarm =
systems?
> >  It boils down to the "connections link" between sensors and control
> > panel of both systems, besides that sensor data connection link both
> > systems are alike.
> >
> > So the comparison is easy, the WIRED WIRES versus a WIRELESS data =
link
> > between sensors and the control panel.
> >
> > WIRED:
> > - Each sensor has "hiss own" cabling, hiss own data transmission =
link.
> >  All attempts to tamper sensor boxes, short or cut sensor wires are
> > detected without any ambiguity an with no delay.
> >
> > - At a first glance the wired links are of the non-frequency =
selective
> > type and as such are more prone to capture a greater Radio Frequency
> > (RF) spectrum range of signals.
> >  The data transmitted on sensor wired lines are of the low frequency
> > type and as such can easily be filtered at all inputs entering the
> > control panel.
> >  This makes the system data link low frequency selective by
> > attenuating the eventual High Frequencies reaching the equipment by
> > huge power transmitters.
> >
> > - The level of the transmitted signals on the wired lines are around
> > "2Volt" to switch from on to off (to be more precise, 400mV
> > interference free immunity for TTL circuits).
> >
> > WIRELESS:
> > - All the sensor data is vehicle via ONE wireless data link composed
> > of a low power transmitter in the sensors and a sensitive receiver =
at
> > the input who has around 4 microvolt input sensitivity (wired 400
> > millivolt (mV) / wireless 4 microvolt (uV) =3D ratio 100 000 times =
less
> > power required to disturb wireless systems)
> >
> > - The wireless data link contains all the information required to =
have
> > a reliable connection as long as there are no other transmissions
> > present who block the data communication.
> >  The wireless RF receiver collect in normal circumstances the data =
and
> > decode it. This data contains an ID (rolling code), alarm, tamper
> > attempt, battery low and more information. When the signal is
> > disturbed, EVERYTHING is, ID can't be recognized...
> >
> > The receiver:
> >   The receiver is made as much as possible frequency selective and
> > sensitive at signals on the frequency in order to capture the week
> > signals emanating from the sensors (see below).
> >  They "attenuate" more or less, depending on the quality of the
> > receiver, the frequencies beside that privileged frequency, its =
called
> > the bandpass attenuation range (essential quality comparison data =
not
> > provided and published by the manufacturers in order to mask how bad
> > the bandpass is).
> >
> > The sensor transmitters:
> >   In wireless alarm systems the transmitting power is limited by law
> > and by reasonable battery live time.
> >   The RF transmitter power of the sensors is of the order of 10
> > milliwatt (mW), low, very low.
> >
> > COMPARISON:
> > - The receive end is 100,000 times more sensitive to signals in
> > wireless versus wired (4uV / 400mV);
> >  The ratio is even higher because the high frequencies, where
> > disturbing transmissions occurs, are attenuated by low pass filters =
at
> > the input of the wired lines.
> >
> > - The link in wired systems are wires who can be filtered/shielded
> > against RF interferences (and by location of the wires); in wireless
> > it is the open air reachable by everybody, no shielding possible.
> >
> > CONCLUSION:
> > - An external RF transmitter can disturb both systems but the power
> > required to do this is much higher in wired systems (>100,000 =
times).
> > - In wireless systems, the power required to interfere and disturb =
the
> > system is similar to the sensor power (10mW) when generated at the
> > same distance, RFI power should be increased if the distance is
> > increased.
> > - Wireless alarm systems are not reliable, they can be interfered =
and
> > disturbed/muzzled due too and by an outside transmission.
> >
> > FINAL NOTE:
> > - Don't forget that in order to interfere wireless alarm systems =
that
> > the RF disturbing signal source should satisfy some frequency
> > requirements.
> >  For example; cell phones with theyre 2 watt power don't satisfy =
that
> > frequency dependent requirement and as such don't disturb normally.
> >
> > Paul
> >
> >=20
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>