First: Unreliabel Wireless Alarm Systems
David Kratz
".Pau|. . i disregard all email send to me" -- NO SHIT, so does your ISP
wrote
> Top NOTE:
> RFI stands for "Radio Frequency Interference" and take place when two
> or more transmitters are present and received at the same time; the
> wanted sensor wireless data signal + an external transmission not
> emanating from system.
Ever hear of spatial diversity? You know, TWO seperate receiving circuits
located a 1/4 wave apart?
The TWO receivers are never on at the same time. Figure it out genius.
William Allen Scheer
say that there aren't many others, but let's just do the simple ones right
know, the ones which anyone with any education in radio technology would
understand, but Paul (who claims to have a great deal of technical
knowledge ) clearly does not:
".Pau|. . i disregard all email send to me" wrote
> Wireless Alarm Systems are unreliable during RFI.
As a genearl statement, this is an unproven assertion devoid of any factual
backing.
> This happens often by transmitters located in the vicinity of your
> premises; even inside your home like it happened to me.
> I had a bad experience with a wireless stereo headphone for TV and
> audio (sold by 1000's in general stores) operating on 433.9 MHz
> (frequency used by a lot if not most wireless alarm systems).
> That wireless headphone is nothing fancy, nothing specially designed
> to cause RFI but it was there and my system was muzzled, inoperative.
Two points of interest:
1) The 433.9MHz band is NOT used by most alarm systems, although it is
common enough in the UK. What is "a lot"? There certainly are not a "a lot"
of 433MHz alarms systems sold in the U.S., Canada , Japan, or Australia. The
319.5MHz band is far more common outside the UK - where the VAST majority of
wireless alarm system are sold.
2) Wireless headphone systems using the 433MHz band are not widely available
in the U.S., Canada, Japan, etc. - most systems are either IR (which avoids
the whole RF issue to begin with) or operate in the 900Mhz or 2.5 Ghz bands.
The 319.5MHz band has never been used for wireless audio in the U.S. AFAIK.
although it is used by some wireless remote-controls.
> You see its not intruders only who may cause RFI..
> "Involuntary" interference caused around or in your home is the worst
> because:
> YOU DON'T KNOW IT that your system is DEAF on signal reception,
> and DEAD on warning.
Simply incorrect. DSC, ITI, Ademco and Inovonics systems (and many others)
have jam-detection features which will alert the user in cases where RFI is
likely to affect operation. This is not an "imaginary" feature, as Paul
often refers to it. It can be demonstrated by any competant dealer/installer
of the product lines I have mentioned. Paul will try to avoid this simple
fact by requesting ever-increasing details about the theory and method of
operation of these features.
> Since the begin i want to point as a minimum to the pro's that
> "involuntary" blocked wireless alarm systems problem, i wanted to warn
> them about it regardless the fact that it can be provoked with a
> simple low power (portable) transmitter from the outside by intruders.
Just not true of any of the product lines I have mentioned - and this is
demonstratable.
> Since i mentioned that, at a sudden pro's discovered the "Radio
> Frequency Interference" (RFI) problem and started to be concerned
> about the effect on they're selling image and profit.
Just not true. Most "pros" were well aware of the _potential_ RFI problem
long before Paul ever started post his nonsense to this group. They are also
aware that current products make this - for all intents and purposes - a
"non issue".
> Instead of looking to the real problem RFI causes, no, pro's try to
> hide reality, they raise unjustified smoke curtains in an attempt to
> generate uncertainty and fear in order to put my statements in doubt.
> Business and financial interests obliges...
No, they can simply demonstrate that the products they sell do not fir in
the same category as the poor-quality system Paul installed in his
apartment. If "Business and financial interests" were really an issue, AND
Paul's assertions were true, most pros would have an incentive to never
again sell or install wireless systems - callbacks are expensive and
profit-destroying.
> Instead of analyzing the problem and submitting it to they're product
> manufacturers for eventual support, no, pro's wanted to "handle" it
> themselves they're way attempting to block my posts.
They don't "block your posts" for anyone but themsleves.
> Pro's have no manufacturer support, they only tell stupidities
> without any valid counter argument, a typical "low education"
> attitude. Look at what happen right now in this NG.
Yes, look what's happening here. Paul steadfastly ignores all counter
arguments, and then claims that none have been made.
> I can understand that alarm installation pro's with they're "low
> radio data transmission knowledge" are not able to open a technical
> based discussion.. Is that the reason why manufacturers don't care
> about that so-called pro's and don't inform them?
It is a simple fact that many in this group have much greater technical
education and experience than Paul. It is also the case that those of us who
do realize that Paul has so little understanding of the subject matter that
any such discussion is pointless.
...
> I had a bad experience with a wireless headphone operating on 433.9
> MHz (frequency used by most wireless alarm systems in the US, AUS,
> UK.. Europe).
Again - simply wrong. the 433MHz band is not used by alarm systems in the
U.S., as can be demonstrated by going to any alarm-parts distributor and
going through their line-card, product catalog and actual products on the
shelf. Test this for yourself - call ADI and ask for a 433MHz system for
sale/installation in North America. The try to find ANY source in North
America for 433MHz headphones. Good luck.
> I thought that my system was functioning correctly during 5 years, it
> was until i purchased a wireless audio headphone, my opinion about
> reliability and protection about wireless alarm based equipment's
> changed.
> I had no visible or audible warning, nothing, the system was just
> muzzled, inactive due to a natural radio phenomena, interference.
> I discovered the muzzling of my wireless alarm system by accident, by
> measuring the wireless receiver audio output.. my surprise when i
> heard TV audio, no sensor alarm burst signals...
Paul bought a cheap, poor-quality system and did not test it or install it
correctly. End of story.
Paul has blown up a personal bad experience with a poor-quality wireless
alarm product (
http://www.jr-international.fr/modules.php?name=Boutique&itm_ref=1845 ) into
a personal "holy war". He keeps insisting that there is some"conspiracy of
silence" regarding all manner of information & specifications for wireless
products.
He has an unusally overblown perception of his own level of intelligence,
education and experience - any of which would have allowed him to avoid his
silly "headphone problem", had he been using any of those particulars in the
first place.
He sees himself as the only person who is either aware (or who will admit)
that the "emperor has no clothes" (his opinion) when it comes to wireless
alarm systems. Any information contradicting his poorly reasoned screeds -
or even correcting any number of factual or technical errors on his part -
are seen as somehow tainted by "low level electrician knowledge", profit
motive or the like. He has made any number of factual errors of the
following kind:
* "The whole RF spectrum is divided and regulated by international
committees who define the allowances on each frequency." [True for shortwave
and some military applications, NOT true for consumer products. The FCC -
for instance - is a US Government organization, not an "international
committee".]
* By limiting the transmission power the signal reception range is reduced
and by consequence the possible mutual interference on that frequency."
[Fails to understand a fundamental radio principle ... namely the the
sensitivity and selectivity of the receiver is the most important determiner
of transmission range.]
* "The possible operating frequency used by ALL alarm systems is known, only
the frequencies 433.92MHz, 868MHz and 345MHz are allowed and available
worldwide." [Just plain wrong. those are the frequencies used in Europe, but
NOT worldwide. 319.5MHz and 900MHz are common frequencies in the U.S.]
Pointing out these types of factual errors does nothing to disuade him.
There is literally NOTHING which can disabuse him of his faulty notions. He
will seize upon some raw factoid like the fact that RF interference does in
fact "exist", as somehow proving his entire case that "wireless alarm
systems are unreliable". He is quite like a religious fanatic in this
respect.
Have fun with him if you like, for as long as it lasts until you tire of
him. Just know that you are talking to an especially "thick" wall. He's a
shining example of why Belgium doesn't export much in the way of
electronics.
Trublechuter
meant to be. Ok what happens if a burglar cuts the telephone line on a
hardwired alarm system. One could come to the same conclusion that in fact
all alarm systems are left useless in certain situtations.
".Pau|. . i disregard all email send to me" <ma...@aol.com> wrote in message
news:kac8hvghmpqgro1l2...@4ax.com...
> Top NOTE:
> RFI stands for "Radio Frequency Interference" and take place when two
> or more transmitters are present and received at the same time; the
> wanted sensor wireless data signal + an external transmission not
> emanating from system.
>
> premises; even inside your home like it happened to me.
> I had a bad experience with a wireless stereo headphone for TV and
> audio (sold by 1000's in general stores) operating on 433.9 MHz
> (frequency used by a lot if not most wireless alarm systems).
> That wireless headphone is nothing fancy, nothing specially designed
> to cause RFI but it was there and my system was muzzled, inoperative.
>
> "Involuntary" interference caused around or in your home is the worst
> because:
> YOU DON'T KNOW IT that your system is DEAF on signal reception,
> and DEAD on warning.
>
> "involuntary" blocked wireless alarm systems problem, i wanted to warn
> them about it regardless the fact that it can be provoked with a
> simple low power (portable) transmitter from the outside by intruders.
>
> Frequency Interference" (RFI) problem and started to be concerned
> about the effect on they're selling image and profit.
>
> hide reality, they raise unjustified smoke curtains in an attempt to
> generate uncertainty and fear in order to put my statements in doubt.
> Business and financial interests obliges...
>
> manufacturers for eventual support, no, pro's wanted to "handle" it
> themselves they're way attempting to block my posts.
> without any valid counter argument, a typical "low education"
> attitude.
> Look at what happen right now in this NG.
>
> 1. Do so called pro's have no credit by the manufacturers?
> 2. Why do they not have support from them?
> 3. Are manufacturers unable to counter-argue too?
> I can understand that alarm installation pro's with they're "low
> radio data transmission knowledge" are not able to open a technical
> based discussion.. Is that the reason why manufacturers don't care
> about that so-called pro's and don't inform them?
>
> Of course everybody know that the technical knowledge pre-requisite to
> be an authorized installer is almost nothing, a little basics in
> electricity, practical zero in electronics and null in radio
> communication.
>
> I had a bad experience with a wireless headphone operating on 433.9
> MHz (frequency used by most wireless alarm systems in the US, AUS,
> UK.. Europe).
> was until i purchased a wireless audio headphone, my opinion about
> reliability and protection about wireless alarm based equipment's
> changed.
> I had no visible or audible warning, nothing, the system was just
> muzzled, inactive due to a natural radio phenomena, interference.
> I discovered the muzzling of my wireless alarm system by accident, by
> measuring the wireless receiver audio output.. my surprise when i
> heard TV audio, no sensor alarm burst signals...
>
> alarm systems (FIRE and INTRUDER), they just don't like to admit it.
> They have recommended and sold so many of them in the past, and still
> do, that it is hard for them to admit that they where wrong to do so.
>
> Pro's with they're irresponsible attitude disgust me,
> you will notice it too and find-out by yourself.
>
> NOTE:
> WIRED alarm systems can be defeated too but not with the same
> ease, they offer a mechanical / difficult access safety of sensor data
> transmission, each sensor has hiss own "individual" data connection.
>
> WIRELESS data connections use "one common" data transport media,
> radio waves and all wireless sensors can be muzzled at ounce with an
> external transmitter.
> An impressive number of transmitters can muzzle the sensor signals
> and none of the available systems are protected against it, even not
> the most sophisticated last once.
>
> More detail about the possible disturbing transmitters types will be
> given in an other post.
>
> Paul
>
Petem
> Why do they not search support from they're product manufacturers?
> 1. Do so called pro's have no credit by the manufacturers?
> 2. Why do they not have support from them?
> 3. Are manufacturers unable to counter-argue too?
> I can understand that alarm installation pro's with they're "low
> radio data transmission knowledge" are not able to open a technical
> based discussion.. Is that the reason why manufacturers don't care
> about that so-called pro's and don't inform them?
> Is it the financial aspect that prevails?
Well i am for a fact an electronic technician that deviated from the
electronic business to the alarm and electric business cause i dodnt like to
stand behind a desk and repair/modify/desing radio and all other electronics
stuff
in fact my last year of learniong was almost dedicated to radio
electronics(My main hobby is amateur radio and i still calculat transmission
line and stuff like that very often) i even took 4 cavities(some filters for
rf) and modify them from being in a band pass configuration to a notch
configuration so i could use them in a diplexor for building a repeater in
the 2 meter band...
so when it come to RFI i know what i am talking about....
now your peice of shit alarm system that you used was not well designed,was
clearly a cheap gizmo and can not be compared to what the PRO install ona
day to day basis,Now if you could comapare apple with apple and orange with
orange it would be very interresting to discuss with you,BUT since you just
want to understand i will be sending mail to ab...@comcast.net till you shut
up or you understand..
By the way if i ask you to just give me the formula on how to calculate the
reactive inductance value of a coil of .5 henry at a frequncy of 433.9 mhz i
am sure you just cant...
now just to check try to find with one of those 4 answer it is....
a) 433.998 Kilohoms b) 3.724 Kilohoms c)1363 Megahoms d)2.165 Gigahoms
> Of course everybody know that the technical knowledge pre-requisite to
> be an authorized installer is almost nothing, a little basics in
> electricity, practical zero in electronics and null in radio
> communication
.
thats not true if the tech dont want to stay at wiring bungallows and
playing with small alarm system
By the way go get yourself a life
Pierre Martel
www.fipoe.org
www.protectron.com
Petem
figure out that the very bad designed alarm system you got was
uselesss...WOW!!
that just proove to use that you know much about rfi and radio waves....
and yes we can have radio aproved after modifying them,cause most of the
time the mods are there to put them to code..
and my rfi experience is from real life use of transmiter/receiver...
and i didnt want to reinvent the whell with my pipe....cause i was using
some bases from some good resources but that proove to you that i know what
i am doing...
Paul you dont know much stuff and by the way the 600 khz frequecy gap in the
2 meter band is not a proof that you know anything cause any kid that pick
up a 2 meter radio will see it....
you didnt even responded to the simple question, for me the case is closed
you dont even know what you are talking about...
".Pau|. . i disregard all email send to me" <ma...@aol.com> wrote in message
news:clh9hv4va096lhdes...@4ax.com...
> Pierre,
> You base / mention your knowledge by referring to radio ham design and
> more in a true believable way, so its worth that i answer to you
> beside the fact that you feel the need to say:
> > will be sending mail to ab...@comcast.net till you shut up or you
understand..
> What do you think you will obtain from them?
> Silly attitude when you mention that you are clever in electronics..
> Why do you hide you behind somebody else?
>
> NOTE:
> I will snip for clarity, if YOU (the others i will ignore) think
> that i hide something by doing so well let me know and i come back to
> that particular part of your post.
>
> On Tue, 15 Jul 2003 18:41:42 -0400, "Petem" <pe...@nospam.com> wrote:
>
> >> I can understand that alarm installation pro's with they're "low
> >> radio data transmission knowledge"....
> >
> >Well i am for a fact an electronic technician that deviated from the
> >electronic business to the alarm and electric business cause i dodnt like
to
> >stand behind a desk and repair/modify/desing radio and all other
electronics
> >stuff
>
> As some in this NG are pinpointing, i do the same even i consider it
> not valid in the whole and most important context but..
> You mention that you MODIFY radio, can you state how you get that
> equipment approved again?
>
> >in fact my last year of learniong was almost dedicated to radio
> >electronics(My main hobby is amateur radio
>
> I'm a radio ham to ON4KG.
>
> Note:
> Persons who mail / post / publish or use my telephone, private
> address information with the intend to harm and / or divulge it to
> third party's will be brought to justice according the universal
> personal privacy law applicable in Belgium. Last warning.
>
> > and i still calculat transmission line and stuff like that very
> > often...
>
> Clever, i used those "pipes" to but never tuned them for a 2m relay
> station. I realize the difficulty to realize that but keep in mind
> that a lot of documentation is available about that particular case, i
> don't want to invent the wheel again did you?
>
> >so when it come to RFI i know what i am talking about....
>
> You certainly realize that what you mention is not RFI but rather a
> very particular case of receiver de-sensibilisation due to the build
> in repeater transmitter transmitting 600KHz beside the considered
> receiver frequency.
> That doesn't cover the general aspect of RFI+ i talk about where
> outside transmitters operates in specific and not unique transmission
> frequency environment.
>
> >now your peice of shit alarm system that you used was not well
designed,was
> >clearly a cheap gizmo and can not be compared to what the PRO install ona
> >day to day basis,Now if you could comapare apple with apple and orange
with
> >orange it would be very interresting to discuss with you,...
>
> Well, well what do you attempt to let believe?
> Is it you that i have to tell that receivers are sensitive to RFI+?
> I admit that better receiver designs can improve the RFI+
> susceptibility, but that they avoid RFI as you tend to let believe,
> tell it to some uninformed electronic person but not to me.
>
> >By the way if i ask you to just give me the formula on how to calculate
the
> >reactive inductance value of a coil of .5 henry at a frequncy of 433.9
mhz i
> >am sure you just cant...
>
> Do you not know about the ARRL handbook?
>
> >now just to check try to find with one of those 4 answer it is....
> >a) 433.998 Kilohoms b) 3.724 Kilohoms c)1363 Megahoms d)2.165 Gigahoms
>
> I know Kilo Ohm's (KOhm). What a elementary booby trap question.
>
>
> Hope this reply to your post,
>
> Paul
>
Petem
can you calculate it or not?
by the way i may have a small problem at expressing my self in english cause
i speak french as my primary language
and i switched from electronic the alarm cause i didnt want to stand behind
a desk all day long...
i am more a people guys then a shop guys, so thats why i do service call,and
system integration.
i love to speak with people and i have a very good relation(business wise)
with almost all my costumer(some one are like some people here,asking proof
and not answering question)
so can you tell me what would be the impedance of a 0.5 henry coil at 433.9
mhz or not?
Petem
primaire car voyer vous cher Paul,si vous seriez le moindrement qualifier
vous pourriez comprendre que la valeur de impédance d'une inductance change
avec la fréquence utiliser...ceci est vrais aussi pour les condensateur ce
qui est très pratique car ces deux composante sont la base des radio
communications...sans elle nous n'aurions pu découvrir les oscillateur et
les filtres..
donc la valeur de impédance d'une inductance de 0.5 Henry a 433.9 Mhz n'est
pas 0.5 henry ceci est saveur inductive non sa réactance inductive ce que
j'ai demander....
je peut peut être vous pointer vers la bonne réponse...
xl=2 x pi x F x L
ou F = fréquence
L= valeur en Henry de l'inductance
pi = 3.1416......
si vous vouller je peut aussi vous donner la formule pour la réactance
capacitive
xc= 1/2 x pi x F x C
ou cette fois C= capacité en farad de la composante
et pour quoi pas la fréquence de résonance d'un circuit LC
Fr=1/2 x pi x Radical L x C
maintenant avec toute ces donner vous pourrez me donne la formule pour
trouver impédance d'un circuit combinant des composante résistive,capacitive
et inductive????
je ne le crois même pas...votre connaissance de électronique est aussi
faible que votre capacité a assimiler les informations sur le groupe de
discutions...
Paul arrêter de faire le pitre, manger votre frite mayo,avec un belle
rousse(bière) et contenter vous de faire ce que les belges devrais faire le
plus..CE LA FERMER.............
".Pau|. . i disregard all email send to me" <ma...@aol.com> wrote in message
news:s8echvs7ir8gde238...@4ax.com...
> Le seul problème que vous avez n'est pas la langue mais bien votre
> incompétance en electronique, voir telecomunications.
>
> Bien que votre question est ridicule, si vous voulez savoir
> l'impédance d'une bobine d'un 0.5 henry.. et bien c'est 0.5 henry a
> toutes les fréquences, par contre la réactance est différente et je
> suis sur que vous savez me la fournir, répondre.
>
> En ce qui conserne la langue, pour moi l'anglais est ma 3ème langue
> après le flamand et le francais.
>
> Paul
> Je me donne pas la peine a corriger les fautes d'ortographe pour vous
> montrez que je m'en contre balance.
> Just for the sake of exactness;
> tell us how you get approval / certification of electronic equipment
> you personally modify and design (your wording follow):
> > repair/modify/desing radio and all other electronics stuff
>
> Its nice to hear that you din't reinvent the piped wheel but that you
> are a perfect copy machine who base themselves on a good sources.
>
> I never mentioned a gap in the 2m band.
> I mentioned a transmitter/receiver offset of 600KHz, that's quite
> different.
> The transmitter do not transmit on the receiver frequency in a
> repeater station and it is why it require a selective receiver
> bandpass and transmitter frequency rejection notch filter to avoid
> receiver de-sensibilisation.
> Do you understand now why it has nothing to do with RFI or do you
> need a more detailed explanation?
>
> You are probably clever in electronics and RFI but you hide it very
> well..
> By the way, i understand now why you "deviated from the electronic
> business to the alarm and electric business"; the requested knowledge
> is less and more in your reach.
>
> Paul
> >to
William Allen Scheer
Nice to see someone tell him in French!
-- WAS
"Petem" wrote in message