Kitz ADSL Broadband Information
adsl spacer  
Support this site
Home Broadband ISPs Tech Routers Wiki Forum
 
     
   Compare ISP   Rate your ISP
   Glossary   Glossary
 
Please login or register.

Login with username, password and session length
Advanced search  

News:

Pages: [1] 2 3 ... 5

Author Topic: My cables  (Read 19443 times)

konrado5

  • Reg Member
  • ***
  • Posts: 896
My cables
« on: September 07, 2014, 11:03:16 PM »

I've took more accurate photos of my cables. Is it all right? The horizontal cable entering into the white round box is phone cable. The large white rectangular box is doorbell. The doorbell cable cross with phone cable at 90 degrees. Furthermore, cable which is parallel to phone cable nearly the white round box is probably additional doorbell cable. Modem is connected to the phone socket by 10 meters long CW1308 (if CW1308 is polish YTKSY). Is phone cable connecting phone socket with white round junction box CW1308 cable?

I'm not sure if this post should be in this thread:
http://forum.kitz.co.uk/index.php?topic=14388.0

I've written about my cables, but I've took very poor photos some time ago.






Best regards
konrado5
Logged

konrado5

  • Reg Member
  • ***
  • Posts: 896
Re: My cables
« Reply #1 on: September 09, 2014, 09:03:03 PM »

Probably I use white-blue pair of phone cable from junction box to phone socket. It is noticable on following photo:


Best regards
konrado5
Logged

kitz

  • Administrator
  • Senior Kitizen
  • *
  • Posts: 32550
  • Trinity: Most guys do.
    • http://www.kitz.co.uk
Re: My cables
« Reply #2 on: September 09, 2014, 09:45:13 PM »

Wiring isn't exactly my forte unless it's something I'm familiar with... So I'll leave it to the other guys to comment.  sorry.
Logged
Please do not PM me with queries for broadband help as I may not be able to respond.
-----
How to get your router line stats :: ADSL Exchange Checker

burakkucat

  • Global Moderator
  • Senior Kitizen
  • *
  • Posts: 31086
  • Over the Rainbow Bridge
    • The ELRepo Project
Re: My cables
« Reply #3 on: September 09, 2014, 10:03:49 PM »

I have downloaded copies of those five images (and rotated three of them) for careful study.

Looking at images numbers 4 & 5 I can see that the flexible lead to the telephone and modem only uses the red and green wires. (I am assuming that there is a low-pass filter for the telephone and the filter, telephone and modem are connected correctly at the other end of that flexible cable.) The internal cable, used to connect the rectangular box with the circular box, looks to be standard 4-core, 2-pair cable and, I would it expect it to be equivalent to CW1308 specification cable. Assuming that they are two twisted pairs, the colouring of the wires' sheaths could cause problems. I see a blue wire & a white wire making up one pair and an orange wire & a white wire making up the second pair. It is the first pair (blue wire/white wire) that is being used. If I was being super-critical, I would mention that there should not really be any exposed metallic conductors showing -- look at the ends of the blue & white wires where they are connected under the screw terminals that hold the green & red wires, respectively.

Looking at image number 3 I can clearly see that the incoming service feed cable (with the black sheath) is a 4-core, 2-pair cable. Once again, the wire colours could cause a problem because they appear to be a red wire & and a clear wire as one pair and a blue wire & a clear wire as the second pair. It is the latter pair (blue wire & clear wire) that is being used and it is connected to the blue wire & white wire pair of the internal cable by means of two gel-crimps. The unused pair of the service feed cable (red wire & clear wire) and the unused pair of the internal cable (orange wire & white wire) are left unconnected. Again, if I was being super-critical, I would suggest that the unused orange wire & white wire pair in the internal cable should not have been left with exposed conductors, twisted together.

Looking at image number 2 it seems as if the service feed cable has been threaded through the existing hole which contains the wire for the door bell. There is not a lot that can be done -- unless you are prepared to have those two cables separated and a new hole created for the service feed cable.

Overall there is nothing particularly "bad" about that wiring and I can't see it being a cause for a degradation in the broadband service. I know that you have noticed that errors occur when somebody rings the door bell. One possible solution would be to fit a spark-suppressing capacitor/resistor series pair across the push button.
Logged
:cat:  100% Linux and, previously, Unix. Co-founder of the ELRepo Project.

Please consider making a donation to support the running of this site.

konrado5

  • Reg Member
  • ***
  • Posts: 896
Re: My cables
« Reply #4 on: September 09, 2014, 10:10:27 PM »

Thank you very much for your reply.
Quote from: burakkucat
I am assuming that there is a low-pass filter for the telephone and the filter, telephone and modem are connected correctly at the other end of that flexible cable.
I has not any phone any longer. I have only modem connected to the socket by 10 meters longRJ11 ended CW1308 0.5 mm diameter. Is it something which can be removed if I have not phone? In the past, I've had bridge tap from the socket to the socket in other room.

Quote from: burakkucat
know that you have noticed that errors occur when somebody rings the door bell. One possible solution would be to fit a spark-suppressing capacitor/resistor series pair across the push button.
I've also noticed errors when I turn off the lightning, when I unplug from the mains computer speakers. Phone cables are nearly the mains box (pink painted box) above the small white square connector.


Quote from: burakkucat
Again, if I was being super-critical, I would suggest that the unused orange wire & white wire pair in the internal cable should not have been left with exposed conductors, twisted together.
What are the possible effects of exposed conductors?

Quote from: burakkucat
One possible solution would be to fit a spark-suppressing capacitor/resistor series pair across the push button.
What is spark-supressing capacitor?

Best regards
konrado5
« Last Edit: September 09, 2014, 11:13:52 PM by konrado5 »
Logged

burakkucat

  • Global Moderator
  • Senior Kitizen
  • *
  • Posts: 31086
  • Over the Rainbow Bridge
    • The ELRepo Project
Re: My cables
« Reply #5 on: September 09, 2014, 11:28:35 PM »

I has not any phone any longer. I have only modem connected to the socket by 10 meters longRJ11 ended CW1308 0.5 mm diameter. Is it something which can be removed if I have not phone? In the past, I've had bridge tap from the socket to the socket in other room.

I don't know anything about the regulations regarding the connection of devices to telephone lines in Poland. All I can say is that without a telephone connected to the line, there is no need for a low-pass filter. Is the modem directly at the end of the flexible cable that is visible in images 4 & 5? (CW1308 specification cable is not flexible, it consists of solid core conductors and should be securely fitted to (say) a wall surface. The cable between the circular box and the rectangular box looks very much like CW1308 specification cable.)

Quote
I've also noticed errors when I turn off the lightning, when I unplug from the mains computer speakers. Phone cables are nearly the mains box (pink painted box) above the small white square connector.

I was wondering about that pink-painted circular cover, as it did remind me of the cover to a recessed junction box containing mains wiring. You have now confirmed that is the case. I would expect that somewhere there is a transformer to supply the low voltage for the bell? Unfortunately I am unable to make any other deductions regarding the bell circuit.

As you are noticing errors occurring when normal electrical items are switched off it seems like the telephone circuit has been installed too close to some mains wiring. The only real solution would be to have the telephone circuit's service feed cable moved, so that it does not share the same route as the door bell wiring and is clear of any other mains wiring.

Quote
What is spark-supressing capacitor?

To suppress the sparking that might occur when the door-bell push button is released, one could fit an appropriately sized capacitor and resistor, in series, across the contacts. See the attached circuit diagram. The capacitor is the component shown by the two parallel plates and the resistor is the component shown by the zig-zag line.
Logged
:cat:  100% Linux and, previously, Unix. Co-founder of the ELRepo Project.

Please consider making a donation to support the running of this site.

konrado5

  • Reg Member
  • ***
  • Posts: 896
Re: My cables
« Reply #6 on: September 10, 2014, 12:08:28 AM »

Quote from: burakkucat
Is the modem directly at the end of the flexible cable that is visible in images 4 & 5?
This cable visible in images 4 & 5 is  specification one twisted pair cable with RJ11 joints. It is on the floor. The modem is directly at the end of this cable. 
http://archiwum.allegro.pl/img/resize?img=http%3A%2F%2F10.193.20.130%2FimagesNEW%2Fac105465280842edd81ebe675b64f03fd346ad007a454482d92fb9fbed85b3d6&type=big
Quote from: burakkucat
As you are noticing errors occurring when normal electrical items are switched off it seems like the telephone circuit has been installed too close to some mains wiring
But I only see 1-2 CRC errors on fast path. I have stable connection with SNR margin 0.9 dB. What is possible effect of installing the telephone circuit close to mains wiring in addition to little errors while normal elecrtic items are switched off? Is it causes lower synchronization rate? I'm curious if I've had 0 errors on SNR margin 0.9 dB at 12 hours when I've had telephone circuit far away from mains circuit. Would shielded cable be helpful?

Quote from: burakkucat
I would expect that somewhere there is a transformer to supply the low voltage for the bell? Unfortunately I am unable to make any other deductions regarding the bell circuit.
My father says this type of doorbell doesn't need transformer. Old doorbells were connected by transformer. This doorbell is connected directly to 230V.

Quote from: burakkucat
Again, if I was being super-critical, I would suggest that the unused orange wire & white wire pair in the internal cable should not have been left with exposed conductors, twisted together.
What are the possible effects of exposed conductors?

Best regards
konrado5

« Last Edit: September 10, 2014, 12:11:36 AM by konrado5 »
Logged

NewtronStar

  • Kitizen
  • ****
  • Posts: 4844
Re: My cables
« Reply #7 on: September 10, 2014, 12:14:30 AM »

You can get wireless door bells which use the 433Mhz radio band, I have an 8 year old wireless doorbell and only needed to replace the batterys twice in those years of service.
Logged

burakkucat

  • Global Moderator
  • Senior Kitizen
  • *
  • Posts: 31086
  • Over the Rainbow Bridge
    • The ELRepo Project
Re: My cables
« Reply #8 on: September 10, 2014, 12:29:06 AM »

This cable visible in images 4 & 5 is  specification one twisted pair cable with RJ11 joints. It is on the floor. The modem is directly at the end of this cable.

Ah, now I understand. It wasn't immediately obvious that the rectangular "box" is actually a socket with the aperture at the top.  :) 

Quote
But I only see 1-2 CRC errors on fast path. I have stable connection with SNR margin 0.9 dB. What is possible effect of installing the telephone circuit close to mains wiring in addition to little errors while normal elecrtic items are switched off? Is it causes lower synchronization rate? I'm curious if I've had 0 errors on SNR margin 0.9 dB at 12 hours when I've had telephone circuit far away from mains circuit. Would shielded cable be helpful?

It is just bad practice and can be a source of errors to the broadband circuit.

Quote
My father says this type of doorbell doesn't need transformer. Old doorbells were connected by transformer. This doorbell is connected directly to 230V.

In that case, if I am correct that the incoming service-feed (the black cable that enters via the centre of the back of the circular box) is sharing the same hole (and route) as mains wiring to the bell-push, then it is extremely bad practice. In the U.K. it would be classified as dangerous and would not be permitted.

Quote
What are the possible effects of exposed conductors?

Another loose and bare wire might make contact. perhaps? It just is not "good practice" and looks as if whoever performed the installation could not be bothered (to do it right).

Please remember, I do not have any knowledge of the standards or the way such wiring should be connected in Poland.  :no:  I can only explain what I see with due consideration of the standards and practices used in the UK.
Logged
:cat:  100% Linux and, previously, Unix. Co-founder of the ELRepo Project.

Please consider making a donation to support the running of this site.

konrado5

  • Reg Member
  • ***
  • Posts: 896
Re: My cables
« Reply #9 on: September 10, 2014, 12:37:47 AM »

Quote from: burakkucat
It is just bad practice and can be a source of errors to the broadband circuit.
Is shielded cable bad practice? I suspect shielding of the phone cable would diminish interferences from the mains wiring.  Does installing the telephone circuit close to mains wiring lower synchronization rate? Is it causes other errors than these errors which I notice while the normal electrical items are switched off? Moreover, I hear crak in AM radio at about 612 kHz when I switch off the electrical items even if radio is far away from the mains wires.

When I was tooking off the cover of the phone socket, I've noticed my upstream SNR margin was jumping about 1 dB every second. Is it something wrong with the internal CW1307 joint of the cable in this socket?
http://postimg.org/image/lyee5osvf/

Phone socket with cover:


What is probable the diameter conductor of incoming service-feed and internal CW1307 cable?

Best regards
konrado5
« Last Edit: September 10, 2014, 02:27:56 AM by konrado5 »
Logged

JGO

  • Reg Member
  • ***
  • Posts: 728
Re: My cables
« Reply #10 on: September 10, 2014, 09:20:58 AM »

Konrado - I suspect it is "What is possible effect of installing the telephone circuit close to mains wiring in addition to little errors while normal electric items are switched off?  " NOT   "screened cable" that  burakkucat is talking about as bad practice.  There probably still is a IEE prohibition on any other wires in the same conduit as 50 Hz wires for safety. 

In your case it can conduct interference near the modem as well.  A filter in the modem mains leads will be more effective if the interference  from other nearby 50Hz wires can't bypass it.   Even if they are not in use for 50Hz, higher frequencies can ignore switches !
   

 
Logged

burakkucat

  • Global Moderator
  • Senior Kitizen
  • *
  • Posts: 31086
  • Over the Rainbow Bridge
    • The ELRepo Project
Re: My cables
« Reply #11 on: September 10, 2014, 02:26:16 PM »

What is probable the diameter conductor of incoming service-feed and internal CW1307 cable?

CW1308 specification cable is typically between the two limits of 0.5 mm and 0.9 mm. The incoming service-feed cable would also be similar.

Quote
When I was tooking off the cover of the phone socket, I've noticed my upstream SNR margin was jumping about 1 dB every second. Is it something wrong with the internal CW1307 joint of the cable in this socket?

It would suggest that there possibly could be a loose connection or the RJ11 plug is not making perfect contact with the connectors in the socket. To eliminate a loose connection, just remake the two joints! Blue wire under the screw terminal from which the green wire link wire to the socket originates and white wire under the screw terminal from which the red link wire originates.

Quote
Is shielded cable bad practice? I suspect shielding of the phone cable would diminish interferences from the mains wiring.

I have no practical experience of using a shielded twisted pair (STP) cable in a telephony installation.

Quote
Does installing the telephone circuit close to mains wiring lower synchronization rate?

I would imagine it entirely depends upon the transceiver circuitry. In other words, how well the induced 50 Hz common-mode "hum" is rejected by the differential input stage of the receiver.

Quote
Is it causes other errors than these errors which I notice while the normal electrical items are switched off? Moreover, I hear crak in AM radio at about 612 kHz when I switch off the electrical items even if radio is far away from the mains wires.

Every electrical item will, when switched off from its power source, generate a small spark across the opening switch contacts. That is why switches are constructed to suddenly "snap" open, thus minimising the time that the opening contacts are still close enough together and allowing a spark to occur. There is nothing particularly special about the 612 kHz frequency. I usually check at 300 kHz, 303 kHz, 306 kHz and 612 kHz. There is electrical "noise" everywhere. The best that anyone can do is to minimise the effect of electrical noise. For an xDSL circuit, using good quality twisted pair cable and ensuring that both legs of the pair have good AC balance will be the first step.
Logged
:cat:  100% Linux and, previously, Unix. Co-founder of the ELRepo Project.

Please consider making a donation to support the running of this site.

konrado5

  • Reg Member
  • ***
  • Posts: 896
Re: My cables
« Reply #12 on: September 10, 2014, 02:42:08 PM »

Quote from: burakkucat
CW1308 specification cable is typically between the two limits of 0.5 mm and 0.9 mm. The incoming service-feed cable would also be similar.
From the socket to the modem I have 0.5 mm. I hope, CW1308 internal cable and external cable also have 0.5 mm. If I know in Poland typical twisted pair has 0.5 mm.
Quote from: burakkucat
I would imagine it entirely depends upon the transceiver circuitry. In other words, how well the induced 50 Hz common-mode "hum" is rejected by the differential input stage of the receiver.
Is mains wire noise noticable in my QLN? This is both upstream and downstream graph from DELT mode.
Quote from: burakkucat
e best that anyone can do is to minimise the effect of electrical noise. For an xDSL circuit, using good quality twisted pair cable and ensuring that both legs of the pair have good AC balance will be the first step.
Has internal CW1308 cable good AC balance? Is it possible to check it on my photos? What is AC balance?

Best regards
konrado5
Logged

Bodge99

  • Member
  • **
  • Posts: 47
Re: My cables
« Reply #13 on: September 10, 2014, 03:04:24 PM »

Hello,

Terminating solid core wire onto a screw terminal: As taught by PO telephones (this shows my age!).

The stripped conductor should be wrapped around the screw (pan head screw with washer assumed) in a clockwise direction. The "tail" should not cross over the conductor. This can otherwise cause conductor failure due to excessive localised compression of the wire.

The screw should then be tightened with the tail brought up vertically. The tail is then cut off flush with the screw head.

See the image for the BT 52a on http://www.telephonesuk.co.uk/connection_boxes.htm

This one is **nearly** correct, but gives the general idea. Actually I would say that the green and white wires are O.K.. No comment required on the lack of cable sheath inside the junction box!

Bodge99.
« Last Edit: September 10, 2014, 04:10:50 PM by Bodge99 »
Logged

burakkucat

  • Global Moderator
  • Senior Kitizen
  • *
  • Posts: 31086
  • Over the Rainbow Bridge
    • The ELRepo Project
Re: My cables
« Reply #14 on: September 10, 2014, 03:11:33 PM »

From the socket to the modem I have 0.5 mm. I hope, CW1308 internal cable and external cable also have 0.5 mm. If I know in Poland typical twisted pair has 0.5 mm.

From the pictures, I am fairly confident that your wiring is of appropriate diameter.

Quote
Is mains wire noise noticable in my QLN? This is both upstream and downstream graph from DELT mode.

I'll attempt to answer that by first asking you a question.  ;)  Would you expect to see it? One "tone" of an xDSL service is 4.3125 kHz wide. The mains frequency is 50 Hz. Think about the scale of those frequencies, it is 86.25 to 1 . . . (Would I expect to see anything? No.  :no:  )

Quote
Has internal CW1308 cable good AC balance?

Yes, of course. It is a stipulation of that specification.

Quote
Is it possible to check it on my photos?

No.

Quote
What is AC balance?

Just as one would expect to see the same DC resistance across the same length of the two legs of a cable pair, so one would expect to see similar AC resistance -- impedance -- for the two legs. (Along with other properties.) Good AC balance for two legs of a cable pair is just a way of ensuring that those two wires behave similarly. Remember an xDSL circuit operates in differential mode, so it is the difference in the signal carried on the two wires that is important. Having two mismatched wires (poor AC balance, non-similar DC resistance, etc) will result in the wanted signal being distorted at the receiver.
Logged
:cat:  100% Linux and, previously, Unix. Co-founder of the ELRepo Project.

Please consider making a donation to support the running of this site.
Pages: [1] 2 3 ... 5
 

anything