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Technical News & Discussion => IDNet Help => Topic started by: woppy101 on Sep 23, 2011, 19:49:54

Title: Interference
Post by: woppy101 on Sep 23, 2011, 19:49:54
Can a power socket cause snr drops and interference?I'm having random snr drops at first I thought it was my heating but I have just had a drop 30mins before the heating has come on,it can't be the street lights because they have never been on/due to switch on or off during any drops.the only thing I can find is when walking round with a untuned radio the plug next to the master socket buzzes like hell, the socket is switched off but still buzzing,when I put it next to another socket that is switched off there is no sound  anyone got any ideas
Title: Re: Interference
Post by: Lona on Sep 23, 2011, 20:19:27
Time you got your house re-wired,woppy. ;D
Title: Re: Interference
Post by: woppy101 on Sep 23, 2011, 20:22:56
I wish but it's an army house so not much chance of that,if I have something plugged into the socket and switched on do you think that will help?
Title: Re: Interference
Post by: Simon on Sep 23, 2011, 20:27:53
Only one way to find out...  ;)
Title: Re: Interference
Post by: woppy101 on Sep 23, 2011, 20:30:44
Quote from: Simon on Sep 23, 2011, 20:27:53
Only one way to find out...  ;)
Have you ever heard of any interference coming from a plug socket
Title: Re: Interference
Post by: Lona on Sep 23, 2011, 20:39:33
I had a socket that made a sound when something was plugged into it and it turned out that it needed re-wired.
Title: Re: Interference
Post by: Simon on Sep 23, 2011, 20:50:25
I can think of instances where extention blocks, power units, etc have caused noise, but I can't recall an actual plug socket doing so.  Doesn't mean it can't happen though, but that's not to say it's the problem.  Sorry not to be more definite.   
Title: Re: Interference
Post by: woppy101 on Sep 23, 2011, 20:56:21
Quote from: Lona on Sep 23, 2011, 20:39:33
I had a socket that made a sound when something was plugged into it and it turned out that it needed re-wired.
Do you mean taking the socket out and reconnecting the wires or putting in new wires all together
Title: Re: Interference
Post by: woppy101 on Sep 23, 2011, 20:57:44
Quote from: Simon on Sep 23, 2011, 20:50:25
I can think of instances where extention blocks, power units, etc have caused noise, but I can't recall an actual plug socket doing so.  Doesn't mean it can't happen though, but that's not to say it's the problem.  Sorry not to be more definite.
I'm starting to run out of ideas for what could be causing these drops
Title: Re: Interference
Post by: Lona on Sep 23, 2011, 22:06:17
Quote from: woppy101 on Sep 23, 2011, 20:56:21
Do you mean taking the socket out and reconnecting the wires or putting in new wires all together

It can just mean checking the wires behind the socket.  They might not be securely connected
Title: Re: Interference
Post by: woppy101 on Sep 24, 2011, 07:28:21
I have plugged on of them smelly things into the socket to see if the constant power draw stops the interference/spike
Title: Re: Interference
Post by: lozcart on Sep 24, 2011, 09:39:49
Can you isolate the power and replace the socket faceplate, they are cheap in DIY stores and see if it solves the buzz.
Title: Re: Interference
Post by: cavillas on Sep 24, 2011, 09:52:26
It could possibly be a loose earth wire in the socket then something else that is working on the same circuit could produce some interference thatis not being sorted out by earthing.
Title: Re: Interference
Post by: woppy101 on Sep 24, 2011, 10:29:53
I have just went round with a radio again and in my foyer you have the master socket then a plug socket and then some heating pipes running up the wall from the floor the the celing,now when putting the radio next to the pipes the radio buzzes the length of the pipe is that normal(if not is there anyway to insulate the pipes to stop the interference)
Title: Re: Interference
Post by: Rik on Sep 24, 2011, 11:24:07
The only thing to do would be to earth the pipes, it sounds like they are acting as an antenna. The socket issue could be that the screws need tightening on the wires into the socket, it could mean that the contacts inside are loose and causing some arcing - I'd replace it, as has been suggested, as that will remove both possibilities.
Title: Re: Interference
Post by: Simon on Sep 24, 2011, 11:25:08
Are you not supposed to get a qualified electrician to do that sort of thing now?
Title: Re: Interference
Post by: Rik on Sep 24, 2011, 11:27:15
Theoretically, maybe. Certainly new wiring requires certification, but I think it's still OK to change an existing fitting - no-one will know as there are no wire colours to give it away.
Title: Re: Interference
Post by: cavillas on Sep 24, 2011, 13:26:29
I always sortour electrical wiring out and I can now change sockets and swithches with power on ;)
Title: Re: Interference
Post by: Rik on Sep 24, 2011, 13:31:21
Nice thick rubber mat, Alf?
Title: Re: Interference
Post by: cavillas on Sep 24, 2011, 16:04:59
Nah! I satnd on the wife. ;D
Title: Re: Interference
Post by: Lona on Sep 24, 2011, 16:09:26
Quote from: cavillas on Sep 24, 2011, 16:04:59
Nah! I satnd on the wife. ;D

Sexist ;D
Title: Re: Interference
Post by: sobranie on Sep 24, 2011, 16:48:46
see next post
Title: Re: Interference
Post by: sobranie on Sep 24, 2011, 16:51:28
A buzzing noise from an electrical socket means something is seriously wrong with the socket or the wiring to the socket.

Turn the electrical socket off – remove any electrical appliances that are plugged into the socket.

A buzzing noise is usually a sign of a bad connection, either something is loose or the wiring is corroded or burnt.

Replace immediately after turning off at the mains fuse box. If you can't, call an electrician.

Title: Re: Interference
Post by: woppy101 on Sep 24, 2011, 17:31:38
Quote from: sobranie on Sep 24, 2011, 16:51:28
A buzzing noise from an electrical socket means something is seriously wrong with the socket or the wiring to the socket.

Turn the electrical socket off – remove any electrical appliances that are plugged into the socket.

A buzzing noise is usually a sign of a bad connection, either something is loose or the wiring is corroded or burnt.

Replace immediately after turning off at the mains fuse box. If you can't, call an electrician.

I think I should explain the socket doesnt buzz at all(it's silent and cool)it's the radio buzz that goes haywire when I place the radio next to it
Title: Re: Interference
Post by: woppy101 on Sep 24, 2011, 17:40:50
But getting back to the interference I put an old dg834g v3 on this morning(renowned for holding a sync even past 0db and a TI chipset same as the exchange), and I had a burst of interference at 1400hrs where the snr was at 0db for around 6minutes and it managed to hold without a re-sync(touch wood lol)!
Even though I will only be 3days into my training period should I report a REIN fault to idnet on Monday?
Title: Re: Interference
Post by: Rik on Sep 24, 2011, 18:04:43
Not unless you're absolutely sure it's external, Woppy, or you could face a large bill. In practice, IDNet can't raise a fault until the training period is complete, so spend the week double and triple-checking your own wiring and equipment. FWIW, when I was using a Netgear, I could get to a -2db reported NM, but I think that Netgears are 'optimistic'. Switching to a 2700 improved both sync speed and stability.

Quote from: woppy101 on Sep 24, 2011, 17:31:38
I think I should explain the socket doesnt buzz at all(it's silent and cool)it's the radio buzz that goes haywire when I place the radio next to it

What's plugged into that socket?
Title: Re: Interference
Post by: Ardua on Sep 24, 2011, 18:38:51
Quote from: woppy101 on Sep 24, 2011, 17:40:50
Even though I will only be 3days into my training period should I report a REIN fault to idnet on Monday?

I assume that when you say 'Army' house you are in fact talking about Service Forces Married Accommodation; that is, a Married Quarter. Rather than tinker with things yourself, I would be inclined to report the matter to the Families Office (or whatever they call them today) and ask for the electrical supply to be checked: that would show up any earthing fault.

I well recall the story of a young airmen who tried to repair an electric bell on his MQ front door. He suspected a wiring fault so he came up with the bright idea of disconnecting the bell power supply wires at the fusebox. He then tried to pull the wires through from the front only to find some resistance. Not one to give in, he pulled some more. The resistance was in fact the fusebox as he had disconnected the wrong wires and he managed to pull it off the wall. A repair with a large bill (after all it was the Public sector and they always add 25% for admin expenses) followed.
Title: Re: Interference
Post by: woppy101 on Sep 24, 2011, 18:43:01
Quote from: Rik on Sep 24, 2011, 18:04:43
Not unless you're absolutely sure it's external, Woppy, or you could face a large bill. In practice, IDNet can't raise a fault until the training period is complete, so spend the week double and triple-checking your own wiring and equipment. FWIW, when I was using a Netgear, I could get to a -2db reported NM, but I think that Netgears are 'optimistic'. Switching to a 2700 improved both sync speed and stability.

What's plugged into that socket?

There is nothing plugged into the socket

I also have the 2700 and while I'd does give better speeds and information it doesn't seem to hold the snr(I had a disconect at 1800hrs but I'm not sure if it was an enforced one from the exchange because I synced lower 3008 and the snr raised to 8db)
Title: Re: Interference
Post by: Rik on Sep 24, 2011, 18:49:26
What firmware are you running? Do all your mains sockets produce similar noise from the radio?
Title: Re: Interference
Post by: woppy101 on Sep 24, 2011, 18:55:54
Quote from: Rik on Sep 24, 2011, 18:49:26
What firmware are you running? Do all your mains sockets produce similar noise from the radio?
No it only seems to be that socket(others do it when something is switched on and plugged in but this one has nothing plugged in and is switched off)
I'm running
dg834 v4.01.28
2700hgv v4.25
Title: Re: Interference
Post by: Simon on Sep 24, 2011, 21:04:02
Would it be worth changing the PSU of the 2700, I wonder?
Title: Re: Interference
Post by: woppy101 on Sep 24, 2011, 21:19:29
Quote from: Simon on Sep 24, 2011, 21:04:02
Would it be worth changing the PSU of the 2700, I wonder?
It's a brand new one out of the box about a week ago
Title: Re: Interference
Post by: Simon on Sep 24, 2011, 21:53:11
Oh...
Title: Re: Interference
Post by: Rik on Sep 25, 2011, 11:33:19
Quote from: woppy101 on Sep 24, 2011, 18:55:54
No it only seems to be that socket(others do it when something is switched on and plugged in but this one has nothing plugged in and is switched off)

What's on the other side of the wall (if it's an internal wall)?
Title: Re: Interference
Post by: woppy101 on Sep 25, 2011, 12:08:20
Quote from: Rik on Sep 25, 2011, 11:33:19
What's on the other side of the wall (if it's an internal wall)?
Another plug socket that the router is plugged into(it's an old house with brick internal Walls not wood and plasterboard) 
Title: Re: Interference
Post by: Rik on Sep 25, 2011, 12:21:37
Check the PSU, then, it could be noisy.
Title: Re: Interference
Post by: sobranie on Sep 25, 2011, 13:24:09
If your am radio picks up noise from the socket then you should change it especially if the router is plugged in on the other side of the wall and is quite likely spurred off the errant socket too.
Sorry to harp on about this BUT you know where the possible noise is coming from so why not take action??? If it's not the socket then you'll have wasted the princely sum of a few quid!!
Title: Re: Interference
Post by: woppy101 on Sep 25, 2011, 17:53:51
Two more disconnects today 8hrs apart,i have now plugged the power supply into I different socket and taken the router as far away from the sockets(have a three meter twisted pair modem cable) as I can.where does the interference normally get into the system ie router,cable or master socket? I think I will give idnet a ring on Monday I have taken print screens of all the disconnects and they all look very similar
Title: Re: Interference
Post by: Rik on Sep 25, 2011, 18:01:50
Are you running Routerstats?
Title: Re: Interference
Post by: woppy101 on Sep 25, 2011, 18:20:51
Quote from: Rik on Sep 25, 2011, 18:01:50
Are you running Routerstats?
Yeah sorry that's where I'm getting the graphs from
Title: Re: Interference
Post by: Rik on Sep 25, 2011, 18:24:47
Can you tie resyncs to falls in NM?
Title: Re: Interference
Post by: woppy101 on Sep 25, 2011, 18:30:20
Quote from: Rik on Sep 25, 2011, 18:24:47
Can you tie resyncs to falls in NM?
Yes(I haven't been taking print screens of the re-syncs I best start)
Title: Re: Interference
Post by: Rik on Sep 25, 2011, 18:32:15
Is there any pattern emerging, eg time of day?
Title: Re: Interference
Post by: woppy101 on Sep 25, 2011, 18:35:17
Quote from: Rik on Sep 25, 2011, 18:32:15
Is there any pattern emerging, eg time of day?
nope there seems to be no pattern(not that i have noticed any way)
here are my line stats from my last disconnect just incase you can see anything
Connection Rate:  3552   Kbps
Line Attenuation: 58     dB
Noise Margin:     5      dB

Max Rate:         3552   Kbps

Interleave CRC:   13
Interleave FEC:   22575
Interleave HEC:   0

Fast path CRC:    0
Fast path FEC:    0
Fast path HEC:    0

Superframes:      212920

Downstream (Rx):
  Good Cells: 911747
  Idle Cells: 30919924
  Bad HEC Cells: 163
  Overflow Dropped: 0

Bytes Transferred (ppp0):
  Tx: 135646790 (129.3 Mb)
  Rx: 37896813 (36.1 Mb)
Title: Re: Interference
Post by: Rik on Sep 25, 2011, 18:39:45
The sync speed seems reasonable for the line length and quality, but there's clearly noise around as demonstrated by the interleave error figures.
Title: Re: Interference
Post by: woppy101 on Sep 25, 2011, 18:53:42
 :laugh:
Quote from: Rik on Sep 25, 2011, 18:39:45
The sync speed seems reasonable for the line length and quality, but there's clearly noise around as demonstrated by the interleave error figures.
Is there a way to insulate the socket from noise?
Title: Re: Interference
Post by: woppy101 on Sep 26, 2011, 08:30:09
Quote from: Rik on Sep 25, 2011, 18:39:45
The sync speed seems reasonable for the line length and quality, but there's clearly noise around as demonstrated by the interleave error figures.
could the errors not be because im downloading at max bandwith
Title: Re: Interference
Post by: Rik on Sep 26, 2011, 10:52:01
Well, the more data that's transferred, the more errors will show, but it's still a sign that there's noise affecting the line.