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[HPsauce]

On the contrary the DMT tool is showing dB per tone which actually looks fine; bit allocation tends to follow that pretty closely. 
It tells us that you're probably still ona 15dB target SNRM though. 

You could try Routerstats of course, see if that shows any more detail.

[westom]

25+kHz would not be audible to humans on the quiet line test I think. 

Any noise on a POTS phone may also be heard at higher frequencies. Furthermore, diminish low band DSL signals need not be due to interior appliances.  For example, calcium has been seen building a bridge to a wire.  This 'connection' may become more problematic with increased humidity. Some signal creating problems (such as a calcium bridge) can be frequency limited.  But generally, noise in those low frequency DSL band would also make noise at lower audio frequencies.  Faint - but distinctive.

  Making a connection directly to the telco master socket with all other interior wires (temporarily) disconnected may report something useful.  Diminished signal during a direct connection to BT means the problem is 100% on their side - can only be fixed by BT linemen or the ISP DSLAM.  Means you cannot do anything to fix what is their problem to solve.

[rwm32]

On the contrary the DMT tool is showing dB per tone which actually looks fine; bit allocation tends to follow that pretty closely. 
It tells us that you're probably still ona 15dB target SNRM though. 

You could try Routerstats of course, see if that shows any more detail.

... But the DMT plot only shows /downstream/ dB per tone, as far as I can see, whereas I believe the OP's question was about how to monitor 25-130kHz frequencies, which are used for upstream bandwidth.

I agree about Routerstats --- that's a good call; I'd forgotten that the more recent versions show bitloading for some modems.

[HPsauce]

I believe the OP's question was about how to monitor 25-130kHz frequencies, which are used for upstream bandwidth.

Certainly one of the issues and DMT would indeed appear to be useless there, but I've just realised:

  Line Rate   4256   288   

Have we been here before? Looks like sort of a fixed rate setup, not ADSL-Max? 

[rwm32]

Have we been here before? Looks like sort of a fixed rate setup, not ADSL-Max? 

This is a question born of ignorance, but... wouldn't a 4mbps fixed rate be 4096 down / 384 up?

[roseway]

I think it's more likely to be just coincidence that the upstream is 288. Hake's connection suffers from variable upstream rates.

[HPsauce]

Yes, on looking back he had 256k upstream as well.

It's very odd though, given the downstream doesn't look too bad. Maybe time to revisit the filters?

[hake]

All microfilters are Exelcus passive.  I intend to replace the ADSLNation filtered faceplate with one like Clarity sell.  At the same time, I will connect straight to the test socket.  Unfortunately, this is obscured by a piece of heavy furniture.  It will have to wait until my Dad has recovered from illness.

The advice I have received is much appreciated and very helpful.

[westom]

All microfilters are Exelcus passive.  I intend to replace the ADSLNation filtered faceplate with one like Clarity sell. 

Making a connection directly to the telco master socket with all other interior wires (temporarily) disconnected may report something useful.   IOW it completely eliminates questions about inferior microfilters AND numerous other problems such as frequency sensitive bridging by calcium growth, and other reasons which are even more obtuse and not listed.

  Calcium bridging was offered as an example of strange things that are known only after tests identify the problem.  Swapping parts will not provide useful (defintive) answers.  A temporary disconnect test - only modem connected to the master socket by a separate and temporary wire) will.

[orainsear]

Calcium bridging was offered as an example of strange things that are known only after tests identify the problem.

Is this when the calcium in damp concrete/building material forms a path between the telephone wire and ground?

[hake]

Damp is not a problem at my house, including the point of entry of the telephone cabling.

[westom]

Damp is not a problem at my house, including the point of entry of the telephone cabling.

  Calcium bridging is an example of strange things that can happen due to normal dampness in every basement, and problems due to desert dry conditions.  All 73 problems tested for by temporarily connecting only an ADSL modem directly to the master socket with all other connections temporarily removed.

  IOW dampness can create problems just like rain only once a month or temperature changes.  Point is to identify the problem at a half way point.  Which side of the master socket causes low band signal degradation?  No reason to even ask why yet.  First, which side of the master socket is the problem?

[rwm32]

First, which side of the master socket is the problem?

Well, I guess the very first thing of all is to wish hake's father a speedy recovery... 

[hake]

Thanks for those kind wishes.

[jeffbb]

Hi

just tried Google with "80KHz"(about mid point on UL frequencies ) various bits of equipment use that frequency including  MONITORS . Is it possible that there could be some interference affecting the UL frequencies ?

Regards Jeff?