cancel
Showing results for 
Search instead for 
Did you mean: 

Fitting Filters

Highlighted
Pro
Posts: 1,216
Thanks: 190
Fixes: 1
Registered: ‎11-01-2008

Fitting Filters

I have been trying to eliminate the internal telephone wiring as a source of the frequent but intermittent loss of sync I have experienced recently. I came across this from James Bailey's 'Speed faults: How to diagnose?'
It is also imperative that every used phone socket in your house has a filter attached, whether it is used or not, as failure to do this can cause interference between the analogue (normal voice phone) and digital (Broadband) signals.
My house was built just over seven years ago, and was pre-wired with telephone extensions (5 in total), but only the master socket and one extension are currently used. Both have the filters provided by PN ifitted. Do I need to fit filters to the unused extensions?
If so, the tidy solution would be to have just one filter installed at the master socket so that all extensions are routed through it. Can this be done as a DIY fit or do I need to get BT to change the master socket, and how much is this likely to cost?
My other car isn't a Ferrari
54 REPLIES 54
Highlighted
Grafter
Posts: 5,924
Thanks: 2
Registered: ‎07-04-2007

Re: Fitting Filters

Yes but the adsl modem has to be connected to the master socket. see http://www.adslnation.com/products/xte2005.php
Highlighted
Community Veteran
Posts: 3,789
Thanks: 1
Registered: ‎08-06-2007

Re: Fitting Filters

Technically, you do *not* require a filter in unused extensions.
However, you can often squeeze a small (or in some cases large!)  performance increase our of existing wiring by fitting a filtered faceplate as linked in the post above.
With your current setup, it is possible that your existing extension wiring is acting as an antenna for interference.  Fitting a filtered faceplate will completely eradicate your extension wiring as a source of interference for your broadband signal.
Please note that if you DO fit a filtered faceplate, you will be restricted to connecting your router to the master socket directly (as all the extensions will be filtered!)
Replacing the master socket is a very easy home-fit job if you're comfortable with a screwdriver!
B.
Highlighted
Pro
Posts: 1,216
Thanks: 190
Fixes: 1
Registered: ‎11-01-2008

Re: Fitting Filters

Thanks for the advice.
Had a look at the link to the ADSLnation faceplate, I hadn't realised before that this only replaces the removable lower part of the BT master socket, so I'm assuming that if BT ever came to visit and saw this installed they would not consider it to be tampering with the master socket.
I guess that before I order the faceplate I could test out the reliability by plugging the router and filter directly into the test socket behind the removeable faceplate. Currently the router is connected via microfilter to the master socket, and is likely to remain that way, so I'm not that fussed if all the extensions become filtered.
Squeezing performance is not my aim, I live some distance from the exchange and don't expect to get better than the 500kbps I get now, but what I really want is a connection that I can rely upon when I need it. I'm hoping that if I can achieve this then I will get fewer re-sync events and more stable speeds, rather than the current fluctuations between 80kbps and 600kbps.
My other car isn't a Ferrari
Highlighted
Community Veteran
Posts: 3,789
Thanks: 1
Registered: ‎08-06-2007

Re: Fitting Filters

Plugging into the master test socket will give you an excellent indication of the speeds and reliability you can expect if fitting a filtered faceplate.
Try it!  Post your line stats from your router when plugged into the test socket and we should be able to give you an indication of connection speed and reliability
B.
Highlighted
Community Veteran
Posts: 6,736
Thanks: 13
Registered: ‎02-02-2008

Re: Fitting Filters

Quote from: Barry
Replacing the master socket is a very easy home-fit job if you're comfortable with a screwdriver!

And a punch-down tool for the IDC connectors.  Crazy
(my local hardware shop sells them for about £2)
Highlighted
Community Veteran
Posts: 3,789
Thanks: 1
Registered: ‎08-06-2007

Re: Fitting Filters

True - When I last ordered the ADSLNation faceplate, they included a cheapo plastic Krone tool with it which did the job perfectly Smiley
B.
Highlighted
Community Veteran
Posts: 6,736
Thanks: 13
Registered: ‎02-02-2008

Re: Fitting Filters

Not with the 2 I bought recently  Sad
Highlighted
Pro
Posts: 1,216
Thanks: 190
Fixes: 1
Registered: ‎11-01-2008

Re: Fitting Filters

Tried out what Barry suggested this morning.
First got the router stats using the current setup, which I copied and pasted to notepad file.
Then unplugged filter from master socket, unscrewed lower faceplate and plugged filter back into test socket. Waited for router to re-sync (did not reboot, should I have done?), collected the stats again and copied to notepad file for a before/after comparison. Then reverted back to original set-up.
Time was running short and I needed to leave for work, so attempted to email the notepad file to work and post on this forum from there (here, in fact, now). Unfortunately, Outlook Express could not connect to mail servers this morning, not sure if this is a problem of my own making or at Plusnet end (but thats going off-topic so will say no more here).
I'll try again tonight, need to concentrate on work now. Thanks for the advice and watch this post for an update.
My other car isn't a Ferrari
Highlighted
Pro
Posts: 1,216
Thanks: 190
Fixes: 1
Registered: ‎11-01-2008

Re: Fitting Filters

I have posted my router stats as advised. There are three sets
First set is with everything plugged in as normal, i.e. router via filter to master socket, two telephones plugged in via filters.
Second set is with router only plugged into test socket via filter.
Third set back to same configuration as first set
Statistics Downstream Upstream 
Line Rate 256 Kbps 448 Kbps 
Noise Margin 11.9 dB 14.0 dB 
Line Attenuation 15.5 dB 31.5 dB 
Output Power 13.1 dBm 11.9 dBm

Statistics Downstream Upstream 
Line Rate 2368 Kbps 448 Kbps 
Noise Margin 6.0 dB 15.0 dB 
Line Attenuation 63.0 dB 31.5 dB 
Output Power 17.2 dBm 11.9 dBm
Statistics Downstream Upstream 
Line Rate 832 Kbps 448 Kbps 
Noise Margin 7.9 dB 15.0 dB 
Line Attenuation 63.0 dB 31.5 dB 
Output Power 15.5 dBm 11.9 dBm
I really don't understand why the line attenuation changes between first and second set, and I'm not sure I believe the download speed from the second set either.
My other car isn't a Ferrari
Highlighted
Community Veteran
Posts: 6,736
Thanks: 13
Registered: ‎02-02-2008

Re: Fitting Filters

I believe the last 2.  Cheesy
Your attenuation on the first set must have been misread somehow as that implies a 1Km long phone line that would give you 8mbps (and over 20mbps with ADSL2+).

So, get your wiring sorted!  Grin
Highlighted
Grafter
Posts: 5,924
Thanks: 2
Registered: ‎07-04-2007

Re: Fitting Filters

Attenuation is a factor of speed, so higher the speed the greater the attenuation, so your first set have a lower speed so the attenuation will be less. But in my opinion attenuation figures on modems are a bit hit and miss as the modem have to calculate these.
The figures posted suggest that you do have a problem with the internal wiring. Have you removed the bell wiring for the extensions? The removeable bottom plate you only need wires to 2 and 5 the rest can be removed.
Highlighted
Pro
Posts: 1,216
Thanks: 190
Fixes: 1
Registered: ‎11-01-2008

Re: Fitting Filters

Now I'm confused.
I thought the line attenuation was simply a function of the length of the phone line from house to exchange. Apart from the first set of stats, the downstream attenuation has always been 63dB, irrespective of the line rate. I use a Voyager 210 router rather than a modem, does this have any impact on how the stats are calculated?
Also, from other threads I have read the bell wire is stated as being on terminal 3, so for the extensions to only need terminals 2 to 5 connected how can this be correct. Also, if I plug into the test socket or master socket then the bell wire will still be connected, unless I tamper with the line in which I'm not supposed to do.
I have been running for a few days with the router and one phone connected via the same filter directly into the test socket. I am still getting occasional disconnects, but not as frequently as before. Will gather some more line stats over the  week to monitor any changes, and also some BT speed test results. Is there a tool I can use to monotor the frequency of disconnections?
Thanks for all the helpful advice, I will thoroughly and systematically test all the extensions and filters to see if I can improve the reliability, and if the speed improves that will be a bonus.
My other car isn't a Ferrari
Highlighted
Grafter
Posts: 1,619
Thanks: 1
Registered: ‎26-07-2007

Re: Fitting Filters

Quote from: itsme
Yes but the adsl modem has to be connected to the master socket. see http://www.adslnation.com/products/xte2005.php

Not necessarily so,  you can now get master socket filtered faceplates that allow you to run a dedicated ADSL extension - see here.
ADSL Nation and Solwise also provide faceplates which allow an ADSL extension.
Highlighted
Community Veteran
Posts: 3,366
Thanks: 15
Registered: ‎06-04-2007

Re: Fitting Filters

Quote from: maranello
I thought the line attenuation was simply a function of the length of the phone line from house to exchange.

For the purposes of ADSL, you are correct it is a constant in the 1 to 10MHz range used by ADSL.
SW.
--
3Mb FTTC
https://portal.plus.net/my.html?action=data_transfer_speed