Internal Telephone Wiring Via CAT 5

Raiser

Signed up for Smarts 8MB package a while back and ran into problems due to a high downstream attenuation of 53-57dbs.

Once the modem was plugged directly into the Master Socket the attenuation dropped to 40dbs - which should be good enough for [in theory] an 11-12MBs DSL package. Clearly the existing wiring [with rough spliced junctions branching off for the phone line and the alarm dialler] was not up to scratch.

I then replaced the lot this weekend with CAT 5 Now my downstream attenuation is the same in upstairs as it is at the master socket [40dbs - 0 loss]. However this got me thinking as I now have the luxury/extra options of what is in effect four independent twisted pair lines going from my master socket to the attic. This is bearing in mind the fact that the house phone [base unit for cordless phone] and alarm dialler line need to be wired in & I'm anxious to do this without polluting my nice clean DSL line :eek:

So & to get to the point - what is the best way to utilise the existing wiring now that I have a couple of options. The two ideas below are as far as I've gotten on this - but to be honest I'm not too sure whats the best way to approach this. I know that System A seems to have the attraction of being simple & straight forward etc. & then I suppose that System B just has the net effect of adding unwanted length onto the line [?] I also noticed on a quick test of System B that just adding a microfilter to the pair being utilised by the phone line pushed the attenuation up by 7dbs [?] - Was just wondering if anyone has the knowledge or experience on the best way to approach this.



In the UK and elsewhere it seems that it is commonplace for people to install a filtered DSL faceplate on their master socket http://www.adslnation.com/products/xte2005.php - apparently Eircom has a version for the average Irish NTU - but it seems they are an Eircom engineer only install/can't be bought anywhere ? I've seen post here on Boards about this - has anyone managed to source something anywhere?



- I was thinking of just modifying my splitter/filter from SMART ie. soldering the respective CAT 5 pairs to the outputs on circuit board and storing it away neatly in or near the master socket housing.



Finally, from doing a small bit of research on the topic, a lot of people who are worried about accommodating additional line requirements for the home telephone, Sky box and alarm etc. are mentioning fitting a centralised filter in the attic in order to keep the DSL path from your modem to the master socket free from echoed/bouncing signals or noise et. etc. etc. - Can anyone advise on this also [?]

- Anyway thanks for reading; would appreciate any help, tips or general advice from the Boards community at large

Raiser.

watty

You can buy ADSL /Phone master filters for Ireland.

The advantage of system B is that other later phone extensions can come from the master.

Use a separate junction box and only the proper connections on the splitter/filter. Then you are not in risk of damaging it and also can quickly plug together alternative or test different filters.

Filters always have insertion loss. More expensive larger ones may have less loss and better separation.

BaconZombie

Just watch out for "Double Dioding".
The filters has a Diode in it and I've seen problem before with Faxes and Phone with base units when put on the same line as a DSL filter due to the Fax/Phone also having a Diode but it wired the opposite way.

So test you setup with both a std phone and then with your cordless one before you start pulling your hair out trying to find the problem.

Raiser

watty wrote: »

You can buy ADSL /Phone master filters for Ireland.

Thanks for the reply Watty; actually I was hoping you were around - I looked for these a few times - Where can you buy these fceking things and becuase you are filtering at the source does it mean that you can add as much copper as you like on the POTs lines without degradation of your DSL?

watty wrote: »

The advantage of system B is that other later phone extensions can come from the master.

Hmmm - not too concerned re. extra extensions, alarm is only other consideration - does that mean that System A is a better option so?

watty wrote: »

Use a separate junction box and only the proper connections on the splitter/filter. Then you are not in risk of damaging it and also can quickly plug together alternative or test different filters.

So you mean at the attic end or located somewhere near the master socket?

watty wrote: »

Filters always have insertion loss. More expensive larger ones may have less loss and better separation.

Damn - I was hoping it was faulty/cheap - I can't afford to add any more attenuation to that line - its currently 40dbs at best - according to this online calculator http://www.kitz.co.uk/adsl/max_speed_calc.htm 43dbs brings me to below the req.s for an 8MB line

BOFH_139 wrote:

Just watch out for "Double Dioding".
The filters has a Diode in it and I've seen problem before with Faxes and Phone with base units when put on the same line as a DSL filter due to the Fax/Phone also having a Diode but it wired the opposite way.

So test you setup with both a std phone and then with your cordless one before you start pulling your hair out trying to find the problem.

Hey BOFH, just hit edit to say thanks 'cause I missed this post earlier on today [sorry] - thanks for that; this is exactly the sort of well-hidden pitfall that could drive a man insane in a very short time!!!!



- Also; the below image is of the removable faceplate [customer side wiring] for an Eircom NTU; can anyone advise on whether there any advantage in using the Alarm terminals [in red] for the SMS dialler on a self-monitored alarm? (P.S. - I edited out my earlier Q. as I found the answer elsewhere re. S1 & S2)

watty

None of the Maplin ones are really any better...
I had a quick look at dabs, expansys, pcworld etc, nothing exciting. Just run of the mill micky-mouse micro filters.

You'll have to do some hard Googling.

Raiser

Thanks for the replies folks - hours or rigorous testing has shown that one twisted pair to the attic & a common as much DSL Splitter/Filter gives excellent attenuation and SNR figures