Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Ezzer]

Hillfly, don't know any one in Kent, furthest south I've worked is just short of colchester when east anglia had a dedicated dsl team.

As for the loop antennea, if you've ever seen inside a MW radio you may have noticed a black bar about 70-100mm long and about 8mm in diameter, wrapped by a yellow/orange thing which might look like wire wound round some paper. this is the loop antennea for MW and LW. A loop antennea is just what it says. for MW you need a big loop several feet across, the black bar in the middle has an effect on the way a loop behaves which means you can make the loop a lot smaller and still pick up the MW range, so making portable radios practical.
The thing with a loop is that is works best when the loop points toward the transmitter. thats why a portable mw radio has to be turned round a bit to improve the reception. the same goes if your looking for REIN. keep turning the radio round by 90 degrees and tip it up on its side as well as you go around.

It's just I'm looking to find a way of making something of a practical size that can look for REIN more easyly than using a radio, and better than the 444b tester we have because that picks up EVERYTHING and round here that means it picks up the Postwick radio transmitters with radio 5 live before it sees anything else

Cheers for the Google link Rizla. I'll have to scan through this at some point. I think the Loop antennea on the us link is refering to the typical directionalality (is that a word or have I just made it up  ). what I'm looking to do is find a way of making a loop more directional with a far narrower beam where the main gain is obtained.

I'm wondering if a version of a "cantennea" set up might work or if fitting ferrite rings around a std ferrite loop could do the same thing, I'll get round to having a play some time soon, no idea if I'll get anywhere, bit of a steep learning curve for me on this one 

[guest]

On a "normal" DF set you have two loops at 90 degrees angle to each other which are then rotated to determine the angle to target. Due to the 90 degree phase difference between the antennae you can get accuracy down to about +/- 3 degrees - ie you'll have an effective beamwidth of about 6 degrees.

What you're referring to as "loop antenna" ezzer, aerial designers would call them "bar antenna". Loop antenna are just that - loops with nothing but air in the centre.

A piccie of a loop DF set is http://jproc.ca/rrp/mdf5_ant.jpg if it helps at all.

[Ezzer]

Cheers for that Rizla, that's one I hadn't come across in the lit' I've looked through so far.

 I'm still a bit new to antennea designs and actual detail as to how they work as opposed to this is an x type and this is a typical y type, have been lighty looking into this over the past few months on and off.
Trying to get some info together so I can try a few things practicaly with out dong the equivalent of a degree in electronics first. not so much run before I can walk but more like get a rough idea of a crawl before walking so to speak

[Hillfly]

Ezzer,

Can you give me some indication what I should expect my BT guys to do when they come to look into the REIN issue?
I must say that I have seen some pretty clueless engineers in the last 9 months and I am hoping that the REIN specialists will be a little more informed.

From my recent graphs i have noticed that the problem seems to occur most frequently between about 5pm and 7pm and i was hoping i coujld get them to visit around this time to give them the best chance of locating the offending device?

Thanks.

[Ezzer]

It's a case of testing the dsl with a test modem using the APtS which is the test program on the openreach laptop and guaging the stats.

There are a couple of options on the APtS program, I tend to go for I tend to go for SFT LLU Healthcheck setting for a few reasons.

With a suspision of REIN I would often bypass the nte altogether and compair stats, but mainly it's a case of hunting round with a MW radio looking for distinct noises, loating the source and trying the stats again with and without the item switched on.

To go for an evening appointment for REIN is tricky, If the engineer isn't on the REIN team here it's  case of trying new e-side & new d-side cable from the exchange to the end user first, new nte5 and fitting an rf3 then the job gets closed with relavent notes under a clear code of 69.0 (all faults would get closed against a miriad of codes which states where the faut was and on the odd one ma raise a report on a list which may mean some further action depending on the notes) which should raise a report somewhere refering to REIN, based on that it's up to your ISP with BT wholesale how they approch this next. Which means pinning a new job to a engineer listed on the REIN team.

Sometimes this may be escalated to a TT engineer, Funny enough I was at an address yesterday where the locality suffered from REIN which popped up in several places in the village and along a 250m run of overhead HT electical cables. By the time TT guys turned up on another day this noise which had been there for some time dissapeared and so everyones broadband came back or improved.

I had one which came up in the evening only a few months ago, I used to swing by on the odd evening if I was commng back late, nothing for several visits, then what definately sounded like the source popped up comming from one of 2 properties, all I could do is knock on the door and hope the occupants would allow me to look for a possible source after i explain what I'm doing, I have no right's in going this far and there's nothing I can do if I do locate this to a 3rd party beyond appealing to their better nature. In this case neither house answered the door. I don't know what came of this as I hadn't heard anything about it after wards

REIN is probably the most arkward and irritating type of fault to prove when you can't locate the source straight away (thats why I would like to look into making something which is a bit more pinpoint tham a radio, part of the problem is the wavelength which makes such a set up unwealdy. for instance an ideal yagi antennea (tv antennea is a type of yagi) would be 238m long !)

[Hillfly]

Well it's been quite awhile but this issue is still ongoing for me.

As yet no REIN engineer has been out despite my fault being with them for quite some weeks now.
It's like they are the untouchables that even the BT wholsesale team cannot get in touch with. My isp keeps calling for an update and little has been done.

I am beginning to think that I should just switch to a fixed rate line and to hell with the MAx product.
Despite getting speeds between 3 & 4 meg during the day (once my BRAS has recovered) i never get above 2 meg in th eveenings once the REIN issue has reduced my sync. The only downside would be a reduced Up speed - which wont help with my online gaming.

Anyone have anty experience as to whther REIN can interfere with a fixed rate line?

[roseway]

REIN is only a form of impulsive interference. If the interference level is high enough then yes, it can interfere with a fixed-rate connection. But fixed-rate connections normally operate with quite large noise margins, so they tend to be more stable than ADSL Max in high interference situations.

[Hillfly]

Well the source of this one is almost certainly a neighbours equipment - though i can't find out who so i am hoping BT rein team can help me find the culprit.

The sync drops from about 4000 to 2000 so it's quite large but not enough to knock out the connection entirely. SNR drops to -3 then a reboot and sync is lower but SNR is stable.

Any idea what sort of margin the fixed rate works on?

[roseway]

Any idea what sort of margin the fixed rate works on?

There's no precise answer to that, but fixed connections generally have a noise margin well into double figures.

[kitz]

>> Any idea what sort of margin the fixed rate works on?

It doesnt as such - the line is fixed to a speed and your router can either "hear" the signal or it cant. 
You will still be subject to SNRM fluctuations, but  theres no target SNR profile negotiation in the same way that there is with Max, as the 2 technologies work differently.

Swings and roundabouts...
Theres nothing like a 15dB Target SNR to give you an additional buffer zone... but without a 15dB target, the line will sync at a higher speed (if its capable).
With Fixed if you loose sync at 2Mb, it wont re-negotiate and attempt a lower speed.  Its 2Mb or nothing.
With Max, some routers will go right down to very low SNRMs.  On fixed, problems may start to materialise at around 6dB SNRM... or even on some carp routers once they get below 10dB.

Theres also some algorithm to do with power output that comes into force too with Max.. in that it will reduce your tx/rx power if the line is very good, which is why the shortest lines seldom see an SNRM over 12dB on Max

With fixed rate you sync on the speed its set at.
With Max you sync at the maximum speed available for your Target SNRM.
Hence SNRM on Max cant quite be compared to the SNRM on Fixed. 

[Ezzer]

Fixed speed reads the signal to noise ratio where as max quotes the signal to noise ratio margin.

So with fixed speed the guide is <9db as the target, teen= average, 20's= very good,30's exellent.

you can only find out you figure after the fixed speed has been applied to you dsl connection

generaly ther'e more stable than max as long as the type of fixed speed your on dosn't exceed the attenuation loss <43db for 2mb,  <60db for 1mb >60db then 0.5mb, this figure will equateto your current db loss within a couple of db's

[Hillfly]

Well I spoke too soon. I got a call from a REIN engineer today.
He has given me his number and agreed to come out one evening when the problem occurs.
Finally I may get to the bototm of my issue after over a year. I hold my breath and await Thursday eveing when he said he would be avalaible to come out.

I had to laugh as despite my ISP giving detailed notes he still thought my connection was dropping out - when in fact all along it was only crashing the sync speed. Misinformation is rife at BT and Openreach I have come to learn.

[kitz]

I think the problem is that the engineer never seems to get all the relevant information :/

Good luck with the REIN specialist

[b4dger]

I had to laugh as despite my ISP giving detailed notes he still thought my connection was dropping out - when in fact all along it was only crashing the sync speed. Misinformation is rife at BT and Openreach I have come to learn.

...connection dropping out and 'crashing' the sync speed sound pretty similar to me 
Surely when your sync crashes your connection is dropping


Good luck for Thursday...

[Hillfly]

...connection dropping out and 'crashing' the sync speed sound pretty similar to me 
Surely when your sync crashes your connection is dropping

Well technically my router maintains a connection despite the SNR hitting as low as -3 - but of course this means no viable throughput is possible.
I have to manually re-sync to get a working snr / sync combination. Hence the BT stats don't show a disconnection.

My problem does seem similar to yours. The odd thing I find is that there are periods when it doesn't happen - such as a friday night. This suggests to me it is equipment belonging to one of my neighbours who likes a drink after work on a Friday. Weekends are erratic but most weekdays the problem occurs around 6 to 7pm.

I'll let you know what we find.