For an alarm - use a whole-house filter or splice in a Dick Smith filter?

Forums › New Zealand Broadband › For an alarm - use a whole-house filter or splice in a Dick Smith filter?

kelly42

44 posts

Geek

ID Verified

#15939 17-Sep-2007 15:12

I've had ADSL for about 3 years in my current house. It has an alarm which is not monitored. I also have Sky Digital and use a line filter behind the Sky box. I'm planning an alarm upgrade which will involve connecting a phone line, allowing the alarm to ring me if it goes off. The alarm company (thankfully a small one) wants to install a whole-house ADSL filter and charge me $120. I'm happy paying this as I don't want to wire the filter up myself.

We use a line filter for Sky Digital even though ihug (my ISP) recommends having a whole-house filter with Sky. They also recommend a whole-house filter with monitored alarms. Is there any reason we couldn't just splice a Dick Smith inline filter into the alarm wiring? It would be much cheaper; is there any advantage either way?

The alarm folks couldn't tell me the make of their ADSL filter but offered me the following numbers. Do they look familiar to you?
MM3200B
20021673

Thanks!

chiefie

I iz your trusted friend
5877 posts

Uber Geek

Retired Mod

Trusted

Lifetime subscriber

#86897 17-Sep-2007 15:42

I'd recommend whole house filter as it is a lot easier (since you don't need the line filter on each phone jack). And I do remember that it is generally better/highly recommended for advanced home security setup too.

Internet is my backyard...

«Geekzone blog: Tech 'n Chips Takeaway» «Personal blog: And then...»

Please read the Geekzone's FUG

stevenb

51 posts

Master Geek

#86918 17-Sep-2007 20:32

kelly42: I've had ADSL for about 3 years in my current house. It has an alarm which is not monitored. I also have Sky Digital and use a line filter behind the Sky box. I'm planning an alarm upgrade which will involve connecting a phone line, allowing the alarm to ring me if it goes off. The alarm company (thankfully a small one) wants to install a whole-house ADSL filter and charge me $120. I'm happy paying this as I don't want to wire the filter up myself.

We use a line filter for Sky Digital even though ihug (my ISP) recommends having a whole-house filter with Sky. They also recommend a whole-house filter with monitored alarms. Is there any reason we couldn't just splice a Dick Smith inline filter into the alarm wiring? It would be much cheaper; is there any advantage either way?

The alarm folks couldn't tell me the make of their ADSL filter but offered me the following numbers. Do they look familiar to you?
MM3200B
20021673

Thanks!

Those numbers are for the Telecom approved ADSL filter as my work supplies them but are only allowed to sell them to Telecom suppliers.You can buy them from Cables Direct http://www.cablesdirect.co.nz/catalog/search?quickfind_needle=adslmaster

Steve

rscole86

4973 posts

Uber Geek

Moderator

Trusted

Lifetime subscriber

#86919 17-Sep-2007 20:35

Some electrical wholesalers sell them aswell, otherwise there are usually a few floating around on auction sites.

cyril7

9058 posts

Uber Geek

ID Verified

Trusted

Subscriber

#86966 18-Sep-2007 08:18

The filter you detail is the Marque Magnetics MM3200B which is the correct filter to use and the only one you should use (its the one Telecom use).

Unless you are upto installing the filter yourself then I would say just let the alarm tech do the business, $120 is not bad, the tradeprice on the filter is just on $70, with discounts the alarm co will get if for around $50 and sell it to you for $70, so they are charging you $50 labour to reconfiguring your wiring to accept both the filter and alarm panel, not an unreasonable price.

Essentially the inbound line will be intercepted, and the filter wired in. The input to the filter (the inbound line) will be connected on one pair of your phone wiring to find its way to the site of your DSL modem. The output of the filter will be wired to a pair to find its way to the alarm panel, the alarm panel will then feed the phone circuit onwards to all your home phones/fax/skySTB. If the alarm panel wants access to the line then it will simply dump the connection to the rest of the house phones (if someone should be on the phone) and gain access to the line all to its self. The important issue is that all phone devices and the alarm panel are via the filter.

You will not require any line filters other than the MM3200B in your home once this is done. Ensure that the cable running from the demark point to the site of the DSL modem is good twisted pair cable (not untwisted), cat5/5e is best but normal cat3 phone cable white sheath with two sometimes three) twisted pairs within is fine, failure to use correct cabling from the demark to the modem will definitely effect DSL performance.

Whole house filtering the ideal solution.

Cyril

kelly42

44 posts

Geek

ID Verified

#86969 18-Sep-2007 08:41

Thanks, everyone, for your replies and help - I've found them very useful.

Cyril, thank you for the description of how the wiring should work once the filter has been installed. Now I can test the alarm company folks (chatting today about a quote) to make sure they are competent to wire the house correctly - though I expect they will be. I'll insist they use cat 5e or 6 cable for the DSL line if possible.

Thanks again for all of the help. This was my first time at Geekzone and I'll be sure to stick around!

tonyhughes

Hawkes Bay
8476 posts

Uber Geek

Retired Mod

Trusted

Lifetime subscriber

#86970 18-Sep-2007 08:58

FYI: for those who ever wondered, here is an explanation of what a demarc point is...

cyril7

9058 posts

Uber Geek

ID Verified

Trusted

Subscriber

#86975 18-Sep-2007 09:39

Kelly, if the cable is already in the walls then dont be surprised if they do not want to replace it. If its cat3 (white with 2 or 3 twisted pairs) then thats fine, if its the old grey stuff that is hardly twisted then it really will need to come out.

Cyril

Equinox IT

Cloud spending continues to surge globally, but most organisations haven’t made the changes necessary to maximise the value and cost-efficiency benefits of their cloud investments. Download the whitepaper From Overspend to Advantage now.

kelly42

44 posts

Geek

ID Verified

#86976 18-Sep-2007 09:48

Currently there is only one jack point in my house (excluding the one put in by the Sky installer a few months ago, which is behind the TV and inaccessible), so by definition we'll have to have another one installed at the time the filter is put in. Cat 6, here I come! :)

cyril7

9058 posts

Uber Geek

ID Verified

Trusted

Subscriber

#86978 18-Sep-2007 09:54

I would not bother with Cat6, I doubt the alarm folk would carry it in their van, they will normally use cat5e which is all you need. Cat5e is more than suited to DSL carrige, as is cat3 and cat5. Cat5e is pretty much the sparkys standard telcom cable these days, its at the best price point and what Telecom recommend in PTC106 for modern home wiring. Cat6 is overkill and still comes at a price premium.

Cat5e (let alone Cat6) is adeqate for 100 and 1Gig Ethenet which uses 100x more backwidth than DSL (including ADSL2+), the real issue is the older grey phone cable that was used in homes 20yrs ago, this has little if any twist in it and is poor at ADSL transmission and prone to noise problems.

Cyril

Niel

3267 posts

Uber Geek

Trusted

#87015 18-Sep-2007 13:15

The central splitter is preferred due to having larger magnetics (i.e. inductors) which does not saturate as easily as the cheap plug-in ones. Also, monitored alarms are hard wired into the phone lines and they will usually not fit a jack plug to plug the alarm into. This is because the alarm also minotors if the phone line is cut/unplugged.

I've installed a D-Link central splitter myself, they are used everywhere else in the world and is also approved for NZ. They retail around $40. The MM splitter is a lot cheaper than $70, but Telecom puts their mark-up on it as well. That said, $120 is a good price for getting a sentral splitter installed.

Part of installing a central splitter also requires installing a dedicated ADSL modem socket which will 99% of the time get brand new wiring from the splitter to the socket. As for the wiring from the splitter to the phone socket(s), quality twisted pair has limited improvement on them. It is the ADSL socket wiring that is important, the rest is filtered with a ballanced filter (no common wire like the cheap plug-in filters).

You can never have enough Volvos!