Kitz Forum

Broadband Related => Broadband Hardware => Topic started by: soms on September 01, 2006, 11:13:10 AM

Title: Shielded RJ-11 line cable - signal improvement?
Post by: soms on September 01, 2006, 11:13:10 AM
Hi guys I bought a Belkin hi-speed internet cable, RJ-11 to RJ-11 for my router and another one for my test modem. I haven't had chance to try it out with the Voyager 105 yet but with my router using the new cable has had a funny effect.

The router took a little longer to sync but now it has the SNR margin seems to be noticably higher. When I unplugged the standard grey RJ-11 cable the stats were 12dB/14dB, have now had the Belkin cable in for a few min and the stats are 18dB/15dB  :)

Perhaps this is another worthy consideration for peeps with low line stats?

I'll have to see if the rise holds out and I when the place is empty i'll whip up the roof to the master with the Voyager 105 and my other cable and see if this is a coincidence or a proper improvement.

Its odd, the other "standard" cables produced the same results and aren't really near anything obviously producing interference. Nearest electrical items are the computer and a desk lamp,which isn't in use.
Title: Re: Shielded RJ-11 line cable - signal improvement?
Post by: kitz on September 01, 2006, 11:39:08 AM
Hi soms..

That is good news - will you let me know about the increase and if it actually stays that way.

Funny enough mr_chris and I had a conversation about the Belkin hi-speed cable about a month back after he spotted their advert for the product.

Hopefully he will/can explain more.
Title: Re: Shielded RJ-11 line cable - signal improvement?
Post by: mr_chris on September 01, 2006, 11:47:36 AM
> Hopefully he will/can explain more.

Not sure what to add, except the price the likes of PC World charge was almost criminal!

It's essentially a piece of CAT5 cable, which is twisted in such a way as to eliminate crosstalk and not pick up any interference. I'm tempted to try something like it myself, to see if my 0dB SNR (at times) can be improved somewhat!

It's certainly worth a go, and as you've seen a visible improvement, that's only a good thing :)

I would be tempted, but I can't find one as long as I would need it. They make an RJ11 - BT plug in 9m (which is what I'd need), but not an RJ11-RJ11 one :(

I could always buy a couple of RJ11 plugs and crimp them onto the end of a piece of CAT5 network cable though... And sell em for a couple of quid each if they prove to work :D

Fancy setting up an online shop kitz? ;)
Title: Re: Shielded RJ-11 line cable - signal improvement?
Post by: kitz on September 01, 2006, 12:03:49 PM
>>> Not sure what to add, except the price the likes of PC World charge was almost criminal!

>>> Fancy setting up an online shop kitz?

lol... yep... cables made to custom length :)


That is something that sometimes is very hard for people to get hold of.

I know that many years ago, when I first set up a home network (on dial up), I wanted a particular length of crossover cable (about 20 ft).  I couldnt get any anywhere despite visiting shops all in and around Blackpool, nor would any of them make one up for me.  PCWorld was charging something like ?16 at the time for a 3 ft length.

In the end it was cheaper to get a network hub that had an uplink port.

Title: Re: Shielded RJ-11 line cable - signal improvement?
Post by: soms on September 01, 2006, 12:11:29 PM
lo guys. I bought the cables cheap from ebuyer, which no dobut you have visited. As you say, 9m RJ-11 to BT but not RJ-11 to RJ-11.

However, you could buy two 4.5 metre leads and use a RJ-11 or RJ-45 coupler  :D

http://www.ebuyer.com/UK/product/54023 (http://www.ebuyer.com/UK/product/54023)

http://www.ebuyer.com/UK/product/113528 (http://www.ebuyer.com/UK/product/113528)

The only problem is the cables are so heavy duty they might very easily pull/fall out of the cheap coupler!

Or as you say make your own. The NTE5 ADSL adaptors actually accept RJ-45 connectors, so if it wasn't for routers using RJ-11 size sockets you could just have used a regular cat5e patch lead. If you want any Cat5e STP shielded cable, I have a reel of it and you can have any length you might want to play with.
Title: Re: Shielded RJ-11 line cable - signal improvement?
Post by: kitz on September 01, 2006, 12:43:22 PM
yeah...  actually I think it was on the ebuyer site that mr_chris first saw the ad for it.

These days Im a lil bit more astute than what I was when I first set up my home network (in 1990 irrc).
Back then there wasnt an ebuyer....  getting hold of any adaptors was hard..  I think the first place that I became aware of that you could buy this sort of stuff was from blackbox...  nor did I know chris back then.
Title: Re: Shielded RJ-11 line cable - signal improvement?
Post by: mr_chris on September 01, 2006, 12:51:05 PM
Nice idea, but not sure a coupler would fit neatly under the carpet though :D

> If you want any Cat5e STP shielded cable, I have a reel of it and you can have any length you might want to play with.

That's very kind of you, and I might actually take you up on that offer. I haven't got any STP, only UTP. I may get a filtered faceplate first (although I have an inline filter in the master socket, so it probably won't make that much difference).
Title: Re: Shielded RJ-11 line cable - signal improvement?
Post by: soms on September 01, 2006, 01:11:34 PM
No problem ;)

I'm just about to go up the attic with this modem and cable. Down here (with modem) the line stats have been identical though there was a minor difference in the ADSLGuide speedtest which I will post up later. Interestingly, though the stats are being very good for the line, the speed test returned a lower value than it has previously. Probably just the net being busier or something. Anyway, i'll test both cables at the master and compare. That should also show if there is any difference or concerns about going from master adapter to a filtered faceplate.

(me presently being at a dedicated ADSL fed socket using Cat5e STP, only wires 2+5 connected with a BT MF50 microfilter)
Title: Re: Shielded RJ-11 line cable - signal improvement?
Post by: soms on September 01, 2006, 02:09:45 PM
My findings on the hi-speed cable:

Well to start with the initial 18dB declined and after 10 min was about 13dB at its lowest. I recon this is just the line conditions which the router seems particuarly sensitive too, it usual varies alot in the day and has previously fallen to 10dB.

What i've done is use the Voyager 105 modem, with both a standard cable, and hi-speed cable in three places - on my dedicated ADSL extension socket, on the front of the master adapter, and at the master test socket.

I then called up the line stats and watched what they did, and finally connected up and did a ADSLGuide speed test.

So, then, the extension socket:

Best sustained SNRM: 15.5dB with both cables. Qaul cable got a line rate of 479.3Kbps and the standard 476.9Kbps.

At the NTE5 ADSL adaptor best sustained SNRM was only 14.5 - 15dB. This was somewhat strange. Probably changing line conditions here rather than signal loss, as this was about 3/4 hour after the first benchmarking. Line rates were worse still at around the 360Kbps mark.

Finally at the test socket, best down SNRM was 16.5dB with line rates going up to 412Kbps and 393Kbps respectively.


My thoughts:

The hi-speed cable I was using was 2 metres. Whilst the standard cable seemed to match it for the most part, the standard cable is about 1 metre long. I have seen problems with ADSL and ordinary telephone extension leads, so those are the ideal scenarios for these cables - where a longer and quality connection lead is required and a flat cable can causes great signal loss. Also the cable seems to work much better on routers, sustaining a slightly better signal rate than that regular cables.
Title: Re: Shielded RJ-11 line cable - signal improvement?
Post by: mr_chris on September 01, 2006, 05:40:34 PM
Soms,

Thanks for that summary. So it seems that whilst the shielded cable offers a slight improvement, it doesn't offer a massive improvement. However over longer distances it might be more of a difference?

OT slighty, but sort of not.. incidentally, I can confirm the signal loss of a flat telephone extension cable - I installed one and plugged the microfilter in at the extension instead of the master socket, and my attenuation went up by 1dB (from 39 to 40) and my previously solid 8Mb became 7Mb because of the SNR drop. I'm still BRAS restricted to an IP profile of 6Mb too :(
Title: Re: Shielded RJ-11 line cable - signal improvement?
Post by: soms on September 01, 2006, 06:05:25 PM
Quote
incidentally, I can confirm the signal loss of a flat telephone extension cable - I installed one and plugged the microfilter in at the extension instead of the master socket, and my attenuation went up by 1dB (from 39 to 40) and my previously solid 8Mb became 7Mb because of the SNR drop. I'm still BRAS restricted to an IP profile of 6Mb too :Sad

Sounds a bit of a pain that. The incident I witnesses was where the extension cable worked and could be used for telephone and dial-up internet access but when ADSL modem plugged into the end of it no signal was registered. It worked fine at the master. This was months ago in the days when I was oblivious to line attenuation, signal strength etc so I was pretty useless really in helping out. I tried out some 2 pair phone cable rather than flat cable but that didn't work either so all I could say was plug it in at the master - out the door and across the hallway 15 metres away from the computer ::)
Title: Re: Shielded RJ-11 line cable - signal improvement?
Post by: kitz on September 01, 2006, 06:31:43 PM
good summary there soms, thanks for posting the info and sharing :)
Title: Re: Shielded RJ-11 line cable - signal improvement?
Post by: kitz on September 01, 2006, 06:36:24 PM
I can confirm the signal loss of a flat telephone extension cable - I installed one and plugged the microfilter in at the extension instead of the master socket, and my attenuation went up by 1dB (from 39 to 40) and my previously solid 8Mb became 7Mb because of the SNR drop. I'm still BRAS restricted to an IP profile of 6Mb too :(

lol...  serves you right for fiddling.
You know how close to the edge your connection is and that you were bloody lucky to get the full 8Mb.
(for anyone that didnt know BT once said his line was only capable of 512kbps)

You couldnt help yourself and leave well alone could you eh?
Womans logic = If its working then dont try to fix it.
 :-X

/me hides from chris


Title: Re: Shielded RJ-11 line cable - signal improvement?
Post by: mr_chris on September 01, 2006, 09:31:11 PM
But... but I wanted to move the phone next to the computer, and.. and.. waah  :'(

So I now have the ridiculous situation of 2 cables running from the puter desk to the phone point.. a telephone extension cable and my broadband cable. And I get better signal that way. Go figure?
Title: Re: Shielded RJ-11 line cable - signal improvement?
Post by: kitz on September 02, 2006, 12:56:45 AM
lol... typical male  :P
Title: Re: Shielded RJ-11 line cable - signal improvement?
Post by: soms on September 02, 2006, 08:48:48 AM
Quote
good summary there soms, thanks for posting the info and sharing :)

Not a problem ;) Whilst that was mostly for our benefit,  if any visitors came looking for info on your forum it would be something else we would "know about".

Quote
So I now have the ridiculous situation of 2 cables running from the puter desk to the phone point.. a telephone extension cable and my broadband cable. And I get better signal that way. Go figure?

This is where you could install a proper fixed extension socket for both DSL/phone, but like me you probably can't be bothered with all the mess and fuss of running cables in walls/floors when instead you can just have trailing wires instead.

Quote
You couldnt help yourself and leave well alone could you eh?
Womans logic = If its working then dont try to fix it.

Perhaps you should have tried it out on an extension after the profiling period, or if womens logic is to be believed, not at all.  Ah well 6meg is still better than 256k or whatever BRAS can set you down too. I can imagine that if we go max it might be hit and miss with what we get.
Title: Re: Shielded RJ-11 line cable - signal improvement?
Post by: kitz on September 02, 2006, 02:07:46 PM
>> This is where you could install a proper fixed extension socket for both DSL/phone

Ironically his desk is probably only 6 foot away from the master socket and in the same room, but it has to go past an entrance arch to the kitchen, so cable at most would possible 12ft?
I was taking the pee outa chris because he had to have a move around of furniture to fit all his stuff in.

Luckily hes out of his profiling period as hes been maxed since end of April and even though his SNR Margin on occasion has dropped to <0, his router has just about managed to hang on in there.
But hes gonna be stuck with a silly 6Mb bRAS profile for about 4 days until it re-adjusts. :/
tbh though I doubt if it will make that much difference because most BT VPs arent able to give you more than 6Mb speeds because of contention anyhow.

The 2 cable thing does seem silly and doesnt make sense, because non filtered traffic is able to flow down the *broadband* cable anyhow.

We both knew that he was extremely lucky to be able to get the full 8Mb, hes talked about trying different routers, and he messed with the bell wire stuff before he got max to try and get his SNR up as high as possible.
iirc we expected him to get 5.5 - 6Mb at most anyhow and tbh I think the only reason he has got the full 8Mb is cause the Netgear hangs on in there when most other routers would have dropped the connection.

A couple of weeks ago he was talking about trying another router to see what stats he got, and I was saying noooooo leave well alone.
Hence me taking the pee outa him now. ;)