Old Computer
Premium
join:2002-04-12
Europe
| reply to Old Computer
Re: A wire is a wire is a wire
I got this about Specs of LEA filters:
Have a look on the attachment.
With one standardized pinning it is possible to place xDSL filters like the ITU-T
G992.1 Annex A (POTS +E1) 600 Ohm and ETSI ATA TS 101 952 -1-1 option
(A) and ETSI ATA TS 101 952 -1-1 option (B) on one PCB layout. |
|
Old Computer
Premium
join:2002-04-12
Europe
1 edit | reply to Bicephale
I already opened the Alcatel filter.
BTW you can't see the cores or capacitors. The box is filled with a sort of hf brown glue. 
Edit : How it looks .. and if you want to buy one ...
»speedtouchdsl.de/shop/product_in···uage=en& |
|
Bicephale
join:2005-09-24 | reply to Old Computer
Hi,
At least, some effort is being made to characterize the Lea filters...
My only disapointment is that it may be pointless to ask Bell for this!
 |
|
Old Computer
Premium
join:2002-04-12
Europe
| reply to Bicephale
Hi Bicephale
Sorry to disappoint you, but the filter is not mine.
I don't have enough good equipment to achieve so good results, and maybe not the intellectual capacities.. lol
You need at least a spectrum analyser, oscilloscope (I have one) and a good BF / HF generator. (And all characteristics of the tores used for).
I got it 1 year ago. It is from Alcatel but not sold public. Was installed by FT some years ago on request.
A nice one is the LEA Filter PCE2B0P-20, but I never could get the diagram.
»www.leacom.fr/page.php?rubrique=···c76e6b88
You can grab the specs in .pdf format.
|
|
Bicephale
join:2005-09-24
 ·TekSavvy Solutions..
| reply to Old Computer
Bonjour Old Computer,
I wish Bell (our phone company like France Telecom
is yours) were offering such quality DSL filters!:
%20.PNG)
High Quality European ADSL Low-Pass Filter (60 dB rejection @ 40 KHz)
Hummm... But i guess FT doesn't carry it neither;
you had to build it yourself, as i recall! Right?
 |
|
Old Computer
Premium
join:2002-04-12
Europe
| reply to Bicephale
Hi Bicephale,
I can't reproduce such graphs with my ST546 V6 but I have changed the house internal wiring completely last week end.
I have now a direct twisted pair 0.8mm wire from the outside connector witch belong to FT. I have installed the master filter you have the diagram (nice filter) just close but inside the house.
I have gain around 300 kbp/s all day with the same SNR due to the auto-adaptive DSLAM keeping 7db SNR. On 24h I got around 60 to 80 CRC errors only with the latest 7xx Firmware.
Also I have put some more "ferrites / Core " on each switching power supply in my room.
So, I am happy with that results. (53 db attn - 4200m from RCO)
 |
|
Bicephale
join:2005-09-24
·TekSavvy Solutions..
| reply to Bicephale
Bonjour Old Computer,
I want you to see this, the ferrite trick works so
well i find it hard to believe. See for yourself:
Tweaks, Bicephale, 2008-Jan-14
It seems i'm accumulating paradoxal static records
here! Sometimes what your see isn't what you get:
%20.PNG)
SpeedTouch 516 Tweaking :), Bicephale, 2007-Dec-11
J'ai beau informer les gens de cette situation, il
semble que même les usagers réguliers du forums ne
remarquent pas les avis en grosses lettres rouges:
SpeedTouch 516 Tweaking :), Bicephale, 2008-Jan-11
Peut-être aurez vous des arguments convainquants à
formuler, moi j'ai eu beau essayer on m'ignore!...
Perhaps you have better teaching skills than i do,
your input on these contradictory readings is more
than welcome. Your experience with radio HardWare
might be usefull, can you shead some light for us?
For example, how come do i worsen attenuation just
by removing toroidal chokes on the DSL phone input
considering we could expect the signal to be a bit
stronger once it's been taken off? Is it possible
that what i've got here is acting like a "loading"
coil but for DSL frequencies? Lets not forget the
SNR Margin numbers and Spectral Response curves...
Am i right to think it's ironic to obtain mediocre
noise performance with an SNR Margin of almost ten
more dB, not to mention the nicer spectral curve?!
I thought this was an interesting riddle you might
want to know of. What's on your tongue? Tell me!
|
|
Bicephale
join:2005-09-24
·TekSavvy Solutions..
| reply to Bicephale
Note.:
I've concatenated the present thread as a one-time
post which became my conclusion for this other one
because together they cover the wiring part fully:
The customer's own wiring, Bicephale, 2007-Oct-30
I also addressed configuration aspects thru a link
to my "tweaks" thread, which completes the picture
as far as an average customer will be concerned... |
|
Bicephale
join:2005-09-24
·TekSavvy Solutions..
| reply to Bicephale
 .JPG/thumb.jpg "200448 bytes")
The Last Straw - Outdoors Shielding |  .GIF/thumb.jpg "42336 bytes")
The Last Straw - Before vs After |
Looking at the amplitude of yesterday's peaks from
12 h to 18 h i notice that those of today, between
7 h and 11 h, were fainter except the last sample. |
|
Bicephale
join:2005-09-24
·TekSavvy Solutions..
3 edits | reply to TSI Steve
And...
Lets not forget an old customisation idea of mine:
«Just thoughts: if my Twin PPP configuration could
be adapted to switch ISPs automatically in case of
a disconnection then a customer who needs to reach
his home PC(s) remotely would have a better chance
to do so.»
Also (while i'm at it)... What about adding value
to our STs by making them even more customisable?:
Thomson SpeedTouch 5x6 & 585 EJTAG "De-Brick" Access, Bicephale, 2007-07-02
Addendum
It seems my thread was interrupted at this point:
A wire is a wire is a wire, Bicephale, 2007-Oct-11
 |
|
Bicephale
join:2005-09-24
·TekSavvy Solutions..
1 edit | reply to TSI Steve
Hi TSI Steve,
I ask because i've had to return my 1st GNet after
a DownGrade... What i like about the GNet BB0060B
is that i can generate 24 h Error Rate curves with
the help of 'DMT' once a day. 'STMT' was supposed
to be able to display a 24 h Error Rate curve also
but it must be left running continuously and i can
not make it work for me, not to mention i wouldn't
like to leave a machine running for one whole week
in order to get one single 7 days record... If at
least the SpeedTouch could send its raw data every
15 minutes thru e-Mail so that external processing
generates curves, euh... it would be good enough.
By the way, a Linux Live CD using SNMP support may
suffice but i don't see that anywhere i look. The
guys at Thomson should explore this avenue, maybe!
Another thing i like relatively to my GNet is that
each bandwidth is adjustable: it allows me to set
the number of tones and their weight - that's what
i refered to as being called "Spectral Shaping" in
previous posts... Finally, i also wrote about the
Twin PPP configuration and i even got some replies
from TekSavvy but that part didn't work. I had to
give up on it but i'm open to future improvements:
when a LogIn account is available it helps to read
the log if two PPP sessions are established to two
different ISPs; it's how i came to know tekSavvy,
as i recall (Rocky offered me a temporay LogIn)...
Can i hope for a custom FirmWare at ChristMass?...
Addendum
It seems my thread was interrupted by the system but it continues here:
A wire is a wire is a wire, Bicephale, 2007-Oct-13
|
|
TSI Steve
TSI Steve
Premium,VIP
join:2007-01-12
Chatham, ON
| reply to Bicephale
said by Bicephale  :Hi TSI Steve, Thanks a lot for sharing your feedback! There's a question which i wanted to ask to people with your kind of expertise for some time now: can you tell in approximate terms what proportion of the return rate was due to flash accidents? Another one that i've been thinkering about lately is what would it take for Thomson and TekSavvy to make an agreement over the development of custom FirmWare which will make the SpeedTouch 5x6 equivalent or better, even when distance is less than 3½ Km as in my case?...  In the case of the GNets, flashing is almost always successful. I literally only dealt with a handful that were due to flashing issues (I am excluding the cases where I was able to manually TFTP in using the serial connection to upload new f/w). On the SpeedTouch side (780 more then any) we've seen a higher error ratio on flashing 'accidents'.
We've attempted to work with SpeedTouch on a couple custom things in the past (in regards to the 780 and VoIP) they responded very well to our needs. It may just be a matter of coming with a good plan and presenting it to them and they may implement it.
Steve
--
TSI Steve - TekSavvy Solutions Inc. |
|
d_l
Barsoom
Premium,MVM
join:2002-12-08
Reno, NV
| reply to Bicephale
The 4100b is probably the equivalent of a generic 4100 modem with a recent firmware. The big difference of the AT&T-versioned 4100b vs. their 4100 was the change to support ADSL2+ in the firmware. Generic 4100 modems are somewhat pricey compared to AT&T versioned 4100 modems on eBay. Because AT&T modems are so common, the prices tend to be lower. If you would use the eBay route to purchase a 4100b, be very careful that it really is a 4100b version.
A straight up purchase of the modem directly from AT&T would cost you $49 plus S&H: »store.att.com/Catalog/ProductDet···d=catMRG
Although your DMT software wouldn't work on the 4100b because the modem's CLI interface isn't accessible when the modem is in DSL use, we have devised a tool to plot the tone bins from the html interface: »SBC DSL FAQ »How can I check for the maximum attainable sync speeds with a 5100b/4100 modem?. Also we have other diagnostics to determine the presence of bridged taps: »SBC DSL FAQ »What do the hybrid numbers mean and what do they tell you about your line?. |
|
Bicephale
join:2005-09-24
·TekSavvy Solutions..
| reply to TSI Steve
Hi TSI Steve,
Thanks a lot for sharing your feedback! There's a
question which i wanted to ask to people with your
kind of expertise for some time now: can you tell
in approximate terms what proportion of the return
rate was due to flash accidents? Another one that
i've been thinkering about lately is what would it
take for Thomson and TekSavvy to make an agreement
over the development of custom FirmWare which will
make the SpeedTouch 5x6 equivalent or better, even
when distance is less than 3½ Km as in my case?...
|
|
TSI Steve
TSI Steve
Premium,VIP
join:2007-01-12
Chatham, ON
| reply to Bicephale
said by Bicephale :About the SpeedTouch, you may have noticed that my appreciation of it differs from the mainstream and i can't say otherwise: put shortly, it's inferior to my GNet in every way and i've shared numbers in previous posts which progressively proved that its reputation sounds a bit over-exagerated sometimes. Hello Bicephale,
We've been noticing your posts about the differences between the SpeedTouch and GNet, to that end we just wanted to let you know that in some cases we agree that the GNet out preforms the SpeedTouch.
For example:
In *your* specific case, when the distance is less then 3/3.5KM the GNet does on occasion out preform the SpeedTouch DSL modems. However, if you get the link up over 3/3.5KM mark the GNets reliability degrades very rapidly.
Overall, for the price GNet's are a decent product when you are less then 3/3.5KM.
I have personally dealt with a few thousands clients that specifically bought GNets. In almost all of the cases where the clients were less then 3.5KM the GNet worked just fine. In the cases where the distance is over 3.5KM we see a lot of issues arise with stability of the link, errors occurring, and the device overall not functioning correctly.
Don't get me wrong, I am not here to bash GNet. We don't bash other companies products. I will note the fact that when we were selling GNet's the return rate for defective devices was around 30% (or more). The return rate on the SpeedTouch 516 is around 2%. The SpeedTouch 546 it's less then 1%. The SpeedTouch 780 (typically related to it's VoIP support) is around 15%. Those numbers are much more manageable.
--
TSI Steve - TekSavvy Solutions Inc. |
|
Bicephale
join:2005-09-24
·TekSavvy Solutions..
2 edits | reply to Angelo_
Hi Angelo,
Do you mean you'd like me to post a drawing of the
phone line configuration? It seems straigtforward
compared to others, there isn't much more to tell;
well, there's a couple inches of wiring going from
Bell's old demarcation box to that white connector
box on its left and i've already explained how the
filters & MoDem connect, euh... but here it goes:
%20.PNG)
This isn't how it looks physically but that's just
equivalent electrically speaking if we except that
ground link which i forgot to implement this time.
About the SpeedTouch, you may have noticed that my
appreciation of it differs from the mainstream and
i can't say otherwise: put shortly, it's inferior
to my GNet in every way and i've shared numbers in
previous posts which progressively proved that its
reputation sounds a bit over-exagerated sometimes.
The very first link at the begining of the present
thread provides various tips relatively to, euh...
lets call it my discomfort about Thomson's ST5x6v6
series. See how a GNet will raise my UpStream SNR
Margin from 8 dB to 22 dB - imagine! - while there
are many such features forbiden to the SpeedTouch.
As i wrote before, i simply can't agree with those
who would qualify it with terms like "trash", etc.
but i don't share the opinion of others saying the
SpeedTouch is a winner neither. I think it's time
to update our collective appreciation of what's on
the market months after the frenzy has past. I do
appreciate your comment about the 3Com, is it from
the USR 910x series? I must confess that i happen
to be curious about the TP-Link units too and i've
asked for reviews on it (well, at least twice, now
that i think of it)... In any case, i welcome all
of the information that people can post on MoDems!
If it's still permissible on Canadian BroadBand...
Addendum
Maybe more clues are required, this should help a bit:
ST546v6, 2007-Mar-12: 4899 errors/day (calculated over 2½ days)
ST546v6, 2007-Jun-6: through the roof!
 |
|
Angelo_
The Network Guy
Premium
join:2002-06-18 | reply to Bicephale
what do you got against the 516 its so great much better then my 3com i bought... and let me tell you what a waste taht was! |
|
Angelo_
The Network Guy
Premium
join:2002-06-18 | reply to Bicephale
map the wire :P |
|
Bicephale
join:2005-09-24
·TekSavvy Solutions..
| reply to d_l
Hi again d_l,
DSL devices are so sensitive i bet this technology
could be used to send messages to Mars, euh... It
wouldn't surprize me that parasitic capacitance is
enough to couple the MoDem to the 60 Hz AC circuit
through its EtherNet cabling, even if an isolation
transformer stands in the path. I wonder, does it
really suffice to run it on battery power or would
i not also need to unplug everything but the line?
This is wild speculation, all i can tell right now
is that the stove is most definitely involved. My
preliminary attempts to shield Bell's main outdoor
weren't conclusive - it's thinner, slotted and the
missing ground lead means that the metal sleeve is
"floating", after all, and requires a revision!...
Trying to measure the error rate simultaneously to
the transfer rate sounds like quite a challenge at
the moment. I'd need to make sure it's CRC errors
which cause lower speeds and i could identify only
one peak per hour so far. You see, i'm not facing
one but two issues; sometimes the phone line will
keep steadily quiet for days with the exception of
kitchen activity but there are days when the noise
is most likely external to our home... During bad
days it doesn't help to measure noise because this
disturbance coming from nowhere will mask reality,
no matter if the stove is being used or not. I've
considered buying a new MoDem, the 4th one i'd try
so far, but my experience with the SpeedTouch left
me with the opinion that newer products just carry
economically-based design optimisations if any!...
You mentioned the SpeedStream 4100B because it has
better rejection of the noise induced electrically
by household appliances. Doesn't this device sell
as a "decomissioned" (customized) refurbished unit
from Bell, etc., or are there suppliers who happen
to have some SS4100B with generic FirmWare? 'DMT'
is a precious tool for me, would it work on it?...
 |
|
d_l
Barsoom
Premium,MVM
join:2002-12-08
Reno, NV
| reply to Bicephale
I've tested my DSL on back up battery power before and it didn't reduce my error rate when I intentionally tried to generate CRC errors. The impulse noise in my electrical lines from those noisy devices is transferred to the wiring in my phone drop by inductive coupling and not through the modem's power supply.
I would recommend that you try to find exactly which electrical devices are causing your errors if you can by powering up individual devices and checking the error counts in the modem. Once you know which devices (I'm assuming that not all devices will cause problems) are causing the errors, then you can jump to testing how much they might affect your download speeds using the method I explained above. When you know how much various error/rates affect your download speeds, then you can target a necessary reduction of the error rates that you can live with and/or afford to have what you consider acceptable download speeds.
You may find that the error rates you are currently seeing hardly affect your download speeds in which case you might be able to live with them. |
|
