Purchasing a Home Alarm

Most of the brands are available in Aus. I would recommend Ademco but you can't buy from the supplier as an end user. You could try DAS.

Reply to
Paul Ekins
Loading thread data ...

Have you ever post-wired a house before? It's an art, not easily learned. You may want to consider wireless.

Ademco is reliable and relatively easy to program for a diy'er

Reply to
Crash Gordon

If you buy a wireless alarm and a keyfob, make sure that the keyfob has cryptation, antiscan and codejopping! (Mine did not, I am sory to say....)

Dovregubben ____________ "I tider med bedrag som dagens orden, er det en revolusjonær handling å si sannheten".

George Orwell _____________

Viktige linker:

formatting link
formatting link

Reply to
Georg Lavik.

Hi I am currently looking to purchase an alarm for my house, I was wondering if anyone could tell me of any good brands that i could look into. I live in australia and i am not sure what the good brands are down here, i will be installiong this alarm myself and i think i want a wired system over a wireless. Any help would be good. Thankyou Jamie

Reply to

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.


- 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).


- 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) = 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 band-pass 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.


- 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.


- 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.


- 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.

Reply to

Good question. Let's review.

It boils down to this. On a wired system, a cable connects the speakers in your headphones to a jack located on the front panel of your stereo system. The impotant thing here is to ensure the headphone jack and the jack on your stereo system are of a similar size. Loose jacks can cause all sorts of problems. For instance, the data link between the the amplifier and your head could become disturbed causing signal loss. You may have to crank up the volume so you can hear "Abba" better.

I almost always use "wired wires" for wiring. Unless, of course, I'm using wireless wires in which case the only thing I'd bring in from the van would be my ladder.

True. but if the connections aren't tight, "hiss"ing may result. Should this occur, it's best to change the batteries on your smoke alarms, then try again.

Not necessarily so. For instance, if you were to leave out the end-of-line resistors, your wired wires wouldn't sense your shorts unless of course they were "Fruit of the Loom", in which case leaving them completely ungrounded wouldn't be a good idea.

In Canada, we always let captured signals go. In fact, I find the Judges at the CRTC to be much too lenient regarding the spectrum range of signals. I don't think that a suspended sentence is an appropriate punishment for non-frequency selective types. And their parol eligibility is ludicrous in the extreme.

Not all data transmitted on sensor wired lines are of a "low character". In fact some fairly ooze class and distinction. It is for this reason that the RF Spectrum is divided into "high brow", and "low brow", with the "Neanderthal" being the accepted unit of measure.

My power transmitter is fairly average, actually. For "huge" you'd have to go to Texas. In Texas they have several different types of transmitters. There's the "short horn" and the "long horn". Long horn frequencies are practically inaudible unless of course you're using Monster (TM) cables.

TTL circuits are only used with "long horn" transmitters to enhance the audible experience. In many cases the circuits are powder coated with Viagra to ensure embedded objects remain fully verticle and the coils fit snugly over them. A small dab of silicon gel ensures proper lubrication during insertion and withdrawl. In many instances over 800mV can be achieved immediately prior to the point of signal injection.

Not necessarily so. Some low brow transmitters are mounted remote from the sensors. It is usually suggested that less sensitive receivers be employed in this instance and that people with small dogs don't allow them to witness the actual mounting process. 400mV applied to a headphone would be enough to startle most small poodles.

Also ensure you change your transmission oil at least every 20,000 miles (25,000 kms). Topping up your fluids should guarantee nominal performance with very little signal loss.

Unless of course a photo is attached. Please ensure photographs of every transmitter is available for when recognition becomes a problem.

Most wide receivers are in fact very selective as to which frequency they catch. CD players sending weekly signals are usually not asked to leave the bench, but in an emergency Gatorade has been known to be helpful in strengthening calls.

Most bands tend to pass by. Those that don't, usually march in place until someone moves the elephant (or the Governor's car).

It's also speed regulated. In most cities the maximum transit speed is 30 mph, however in some places this has been known to be much higher. Higher transit speeds means less transients will leave their shopping carts in traffic.

Not if you use "high bypass turbofan" filters. In this instance the transmissions are less prone to interference from wake vortices, which decreases their attenuation span.

Except for magic missle shielding. Using mithral armored cable is also an excellent way of protecting you from trolls.

Power is reduced when the homeowner uses the Force. Only skilled and well trained alarm installers should use "the Schwarz" and then only as a last resort. Every attempt should be made to remove the jam from the transmitter before applying the peanut butter (or Nutella).

But if the distance is decreased, the RFI becomes DFO and all our fish stocks are endangered.

Wireless alarm systems cannot be muzzled by GM transmissions. Fords and Jugos are by far the worst culprits.

Unless of course your chocolate craving has been satisfied.

For those with disturbing cell phones, we suggest downloading some more ring tones. I quite enjoy the Imperial March whenever the office calls. The Darth Vader helmet also enhances the CRF (Customer Recognition Factor) and , oddly enough, has reduced the number of service calls I have to go out on.

Reply to
Frank Olson

"Jamie" wrote in news:4319457a$0$526$ snipped-for-privacy@per-qv1-newsreader-01.iinet.net.au:

Hi Jamie, I would suggest you contact a local compny for pricing etc as this is one of those things that looks easy, but often isn't. Secondly be aware that ANY cabling work done here in Aust that has any potential to be connected to or is connected to the phone system must be undertaken by a licensed cabler. Currently the fine for non compliance is $12,000 + GST.

Reply to
Me here

Reply to

Cabling-Design.com Forums website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.