Best 'phone extension lead.

wrote:

> I've heard mention before that of the myriad of DIY telephone extension
> leads on the market that some types are better than others for use with
> broadband. Could someone please advise which would be the best to use for
> the least degradation of the BB signal.

If you mean an extension lead to carry the broadband signal, twisted
pair would be good.

Personally I think the best installation is:

1) Single active filter incorporated into or immediately adjacent to the
master socket, separating ADSL and voice.

2) ADSL modem adjacent to above filter, using twisted pair rj11 - rj11
modem lead.

3) Use 2-wire[1] pots equipment throughout.

4) Disconnect the bell wire[3] throughout the voice wiring.

If you have an NTE5, use an active filter faceplate and only connect the
blue pair (pins 2 and 5) on the pots side.

If you have an old LJ style master socket, use an active microfilter to
split out the ADSL and voice, and a patch lead[2] and slave socket to
connect the pots signal to the pots equipment. Only connect pins 2 and 5
(blue pair) on pots sockets.

[1] Three-wire pots equipment can be converted to two wire by any
reasonably competent electronics technician. Multiple the equipment REN
number by 450 nF. Round up to the next E12 or E24 value (typically
470nF, 1000nF/1.0uF, 1.5uF, 1.8uF). Obtain said capacitance with a
rating of 200v AC or higher. Use this capacitor to create a local bell
feed from the BT431A socket pin 2 (or plug pin 5) inside the equipment,
and disconnect the feed from socket pin 3 (plug pin 4). Make sure you
get it right or you'll short circuit the ac ringing signal!

[2] Patch lead can be made with two BT431A plugs and a short length of
flat instrument cordage. Note that you will need to either (a) reverse
one of the plugs on the cable (bump downwards) or (b) reverse the wiring
in the connected slave socket (blue/white to 5, white/blue to 2) to
maintain polarity throughout.

[3] Bell wire was only really needed to prevent bell tinkle with pulse
dialling equipment. If you still have pulse dialling equipment, and use
your line for ADSL, either put up with the tinkle, or, better, get rid
of the pulse dialling equipment! If you must use pulse dialling
equipment and insist on preventing bell tinkle, you'll just have to live
with the reduced ADSL performance of having the bell wire connected[4].

[4] The bell wire acts as an antenna, and feeds signals it receives into
the a/b wire pair. However, as it feeds one wire (usually a) through a
resistor, and the other wire (usually b) through a capacitor, the signal
from the bell wire on each of the a and b wires is at different
amplitudes and phases, and this means that it doesn't appear as a common
mode signal, and so is not rejected by common mode noise reduction
methods inherent in the design, but instead appears as noise across the
a/b pair, competing with the adsl signal.

Rgds

Denis McMahon

Kráftéé wrote:
> "chris" <(E-Mail Removed)> wrote in message
> news:hj9m7s$dpm$(E-Mail Removed)...
>> On 20/01/10 22:57, Flyiñg Ñuñ 2°10 + on netbook wrote:
>>> Hugh Jampton wrote:
>>>> On Wed, 20 Jan 2010 21:30:33 -0000, Flyiñg Ñuñ 2°10 + on netbook
>>>> wrote:
>>>>> I've heard mention before that of the myriad of DIY telephone
>>>>> extension leads on the market that some types are better than
>>>>> others for use with broadband. Could someone please advise
>>>>> which would be the best to use for the least degradation of the
>>>>> BB signal.
>>>>
>>>> But your broadband speed is *very* fast.
>>>>
>>>> Why do you need it any faster ?
>>>>
>> [snip]
>>> With my current trial set up - short extension lead then
>>> microfilter I'm now
>>> getting 6816 kbps and managed to, I hope I'm not being premature, have
>>> not
>>> yet had a dropped connection, but d/l speeds are still less than
>>> 5000 kbps.
>>
>> I don't disagree with the others about the optimum solution.
>> However, a real world example here is that I see no difference at
>> all when comparing sync or d/l speed over a dirt cheap 10m cable on
>> an extension socket vs direct connect to the master socket.
>>
>> I mean, when a signal has already travelled 100s to 1000s of metres
>> to get to your house an extra 10m of sub-optimal cable can't make a
>> huge difference. If the signal is so marginal that it does make a
>> difference, then maybe it's worth the effort, but when you're
>> getting ~5mbps, I doubt it.
>
> Up to the point where it enters the property the cable should be a
> balanced, twisted pair. this should stop most interference problems. When
> it enters the house (after the NTE) then it can start to pick up
> all sorts of RF interference (could give a long list but lets just
> say anything electrical can give of some signals) which can and do
> affect DSL (which is where the Iplate, the newer NTE5 and of course
> the old disconnection of the bell wire at the NTE comes into play, as
> the bell wire is the main culprit)).
>
> With the cheap plug-in extensions you can have 2 problems (well
> actually 3 the third being you can't disconnect the bell wire) one
> being the actual structure of each wire, all to often it's a braided
> mix of aluminium type metal and nylon (this in itself can attenuate
> the broadband signals as well as actually causing 'noise') and
> secondly it's normally a flat cable and so doesn't have the RF
> rejection that twisted pair should have. Remember just because you
> can get a telephone to work at the end of it doesn't mean that DSL
> will/can, also where you run the cable can also cause you grief (I've
> seen them running under halogen table lights, freeview boxes, sky
> boxes and the like and they were always causing problems).
> All of the above doesn't ignore the fact that a localised, strong RF
> signal can affect many users over a distance, this can range from
> just the users on the same pole to the users off the same PCP

Yep. I'm pretty certain that is the case. Over the last few months during
the evenings at random times I get some pretty bad interference on BBC1 -
terrestrial channel. I don't watch BBC1 that often but it can get pretty
annoying when I do. The interference can go on for up to ½ an hour and is
usually in random bursts lasting a few seconds. As I have Sky digital on my
main TV, I just switch over to channel 101 on that. I have never noticed it
on terrestrial BBC2, ITV1 or C4 though. Here's a photo taken on my 'phone
to indicate how bad it can be, and it's accompanied by lots of loud crackle
on the audio. http://www.flyingnun.co.uk/interference.jpg
Seems like there is some strong rogue electrical device nearby that is
causing it.
--
Heard melodies are sweet, but those Unheard are sweeter
(E-Mail Removed) FN 2°°9 +, Mungo Brandybuck of Buckland

Paul Cummins wrote:
> In article <(E-Mail Removed)>, (E-Mail Removed)
> (Flyiñg Ñuñ 2°10 +) wrote:
>
>> I have never noticed it
>> on terrestrial BBC2, ITV1 or C4 though. Here's a photo taken on my
>> 'phone to indicate how bad it can be, and it's accompanied by lots
>> of loud crackle on the audio.
>> http://www.flyingnun.co.uk/interference.jpg
>
> http://www.kyes.com/antenna/interference/tvibook.html
>
> Do you live within 4-800 feet of a Cab firm?

Nope! But about 300 yards from a Supertram terminus though, and they use
pretty large currents and I would think could be prone to a fair bit of
arcing, but then they run all day, and I haven't noticed anything nasty
during the daylight hours. Now I've relocated my 2700HGV to downstairs and
much closer to the phone socket (now fitted witha filtered faceplate, I
haven't had any dropped connections, so it was obviously the extension lead
that was presumably picking up lots of noise to cause massive drops in the
S/N level getting to the router. In the dusk to dawn hours the SNR is now
falling to arond 6 - 7 dB at times, whereas before it could go as low as
2 - 3 dB when the dropped connections were occurring. --
Heard melodies are sweet, but those Unheard are sweeter
(E-Mail Removed) FN 2°°9 +, Mungo Brandybuck of Buckland

Andy Champ wrote:
> Flyiñg Ñuñ 2°10 + wrote:
>> Paul Cummins wrote:
>>> In article <(E-Mail Removed)>,
>>> (E-Mail Removed) (Flyiñg Ñuñ 2°10 +) wrote:
>>>
>>>> I have never noticed it
>>>> on terrestrial BBC2, ITV1 or C4 though. Here's a photo taken on my
>>>> 'phone to indicate how bad it can be, and it's accompanied by lots
>>>> of loud crackle on the audio.
>>>> http://www.flyingnun.co.uk/interference.jpg
>>> http://www.kyes.com/antenna/interference/tvibook.html
>>>
>>> Do you live within 4-800 feet of a Cab firm?
>>
>> Nope! But about 300 yards from a Supertram terminus though, and
>> they use pretty large currents and I would think could be prone to a
>> fair bit of arcing, but then they run all day, and I haven't
>> noticed anything nasty during the daylight hours. Now I've
>> relocated my 2700HGV to downstairs and much closer to the phone
>> socket (now fitted witha filtered faceplate, I haven't had any
>> dropped connections, so it was obviously the extension lead that
>> was presumably picking up lots of noise to cause massive drops in
>> the S/N level getting to the router. In the dusk to dawn hours the
>> SNR is now falling to arond 6 - 7 dB at times, whereas before it
>> could go as low as 2 - 3 dB when the dropped connections were
>> occurring. -- Heard melodies are sweet, but those Unheard are sweeter
>> (E-Mail Removed) FN 2°°9 +, Mungo Brandybuck of Buckland
>>
>>
>
> I'm pretty sure that is caused by an unsuppressed ignition system on a
> petrol engine. Does one of your neighbours tune cars? (or bikes)
>
> Andy

Not in the evenings. In fact, I can't think of anyone except a neighbour 2
doors away, who reached his second childhood when he retired and acquired a
*big* bike. But he only revs that up on warm sunny spring, summer and
autumn mornings before he is off out to re-find his youth. Do I sound
envious? I tried so hard not too.
--
Heard melodies are sweet, but those Unheard are sweeter
(E-Mail Removed) FN 2°°9 +, Mungo Brandybuck of Buckland

Peter Crosland wrote:
>> I don't suppose you've got an unused W98 SE upgrade CD you don't want or
>> any other cheap way that I can preserve the use of my W98 compatible
>> software on my archive computer and get it working on wifi?
>
> Genuine Windows ME upgrade disks are frequently available on eBay for a
> tenner or less.
>
> Peter Crosland

Almost no worries now Peter. I suddenly thought I might get round it by
using a crossover ethernet lead between my main desktop an the W98 m/c, I
wonder why no one else suggeted that possibility? After a few bits of
fiddling around I can now transfer data between all 3 m/cs. That's a
wifi'd to router netbook, wifi'd to router desktop and the ethernet
connected W98 old desktop m/c. Strangely even though I can transfer data
from the netbook to old m/c I cannot yet get the old m/c to connect to the
Internet, even though I have set up a network bridge between wifi
connection and LAN connection on the main desktop. I'm a tad confused by
that though.
--
Heard melodies are sweet, but those Unheard are sweeter
(E-Mail Removed) FN 2°°9 +, Mungo Brandybuck of Buckland

Peter Crosland wrote:
> "Flyiñg Ñuñ 2°10 + on netbook" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
>> Peter Crosland wrote:
>>>> I don't suppose you've got an unused W98 SE upgrade CD you don't want
>>>> or any other cheap way that I can preserve the use of my W98 compatible
>>>> software on my archive computer and get it working on wifi?
>>>
>>> Genuine Windows ME upgrade disks are frequently available on eBay for a
>>> tenner or less.
>>>
>>> Peter Crosland
>>
>> Almost no worries now Peter. I suddenly thought I might get round it by
>> using a crossover ethernet lead between my main desktop an the W98 m/c, I
>> wonder why no one else suggeted that possibility? After a few bits of
>> fiddling around I can now transfer data between all 3 m/cs. That's a
>> wifi'd to router netbook, wifi'd to router desktop and the ethernet
>> connected W98 old desktop m/c. Strangely even though I can transfer data
>> from the netbook to old m/c I cannot yet get the old m/c to connect to
>> the Internet, even though I have set up a network bridge between wifi
>> connection and LAN connection on the main desktop. I'm a tad confused by
>> that though.
>
>
> I suggest the folks in uk.home-networking would be the best to ask.
>
> Peter Crosland

Thanks Peter I'll give that a go when I run out of ideas, which shouldn't
be long now.
--
Heard melodies are sweet, but those Unheard are sweeter
(E-Mail Removed) FN 2°°9 +, Mungo Brandybuck of Buckland