I-plate questions...

There are a fair few telephone extensions in my house (4 in total, alot of wiring) of which my ADSL router is plugged into one of so i figured maybe the I=plate will improve things a bit...except line attenuation has gone up? although slight it's still a difference which i find quite odd, and if anything would have expected a slight decrease...or am i getting things a bit wrong? anyways here are line stats...

Pre I-plate

Uptime: 0 days, 0:00:40
Modulation: G.992.5 Annex A
Bandwidth (Up/Down) [kbps/kbps]: 1,209 / 15,546
Data Transferred (Sent/Received) [KB/KB]: 9.00 / 7.00
Output Power (Up/Down) [dBm]: 12.0 / 18.0
Line Attenuation (Up/Down) [dB]: 9.0 / 19.5
SN Margin (Up/Down) [dB]: 5.5 / 3.5

I-plate fitted

Uptime: 0 days, 0:05:46
Modulation: G.992.5 Annex A
Bandwidth (Up/Down) [kbps/kbps]: 1,217 / 15,546
Data Transferred (Sent/Received) [KB/KB]: 226.00 / 644.00
Output Power (Up/Down) [dBm]: 12.0 / 18.0
Line Attenuation (Up/Down) [dB]: 9.5 / 20.0
SN Margin (Up/Down) [dB]: 6.0 / 3.5

The difference is so small as to be insignificant.
If the device only displays in 0.5dB steps then the difference is even smaller.
There is a chance that a number of re-syncs will result in slightly different figures again.
This may also be due to the modem and line card utilising slightly different frequencies/bins during sync events due to changes in the noise environment each time, particularly during the evening/night.
Basically there is no discernible difference between the before and after figures.

well...you say .5 isnt much but...my attenuation hasn't changed in over a year! Till some muppet decided to very very badly install another telephone extension 2 feet away from one that was already there then it went up 2db which annoyed me greatly -.-

but still...it goes back down .5 again when i remove the i-plate and goes it when i put it on etc etc...

Thats right. 0.5 dB is not much. If your device displays in 0.5dB steps only then diference may be as little as 0.1 dB.
The rest of the figures are basically static so the I-Plate has not made any discernible difference.

Where did you fit the iPlate?
Are these 4 extensions actually all the same telephone number?

If you fitted the iPlate at the master socket, and the 4 extensions are connected off of that faceplate, then if you extension wiring is NOT twisted pair cable this cable may be the source of noise pick-up.

That said the performance is reasonable, not brilliant for 19dB attenuation, but I doubt the provider will worry

Don't fixate on attenuation, the noise margins are the critical thing.

Buy DECT phones, and do away with the extensions.

that's quite easy for you to say but...
1) there arent any actual phones on the line, but there is a printer/fax machine and 2 sky boxes, nothing i can do about them.
and do away with the extensions also isnt possible due to said fax/sky boxes and, if you read my original post, my router is on one of the extensions.

Some faxes are known to cause problems, so choice of filter with them is very important. It was generally older machines but it is worth trying without any of this kit plugged in

This is possibly or even probably caused by the common mode choke the iPlate inserts in the signal pair. It can't possibly be caused by the choke in the ringwire and the common mode choke is the only remaining component in it.

In reply to a post by NBK:

that's quite easy for you to say but...
1) there arent any actual phones on the line, but there is a printer/fax machine and 2 sky boxes, nothing i can do about them.
and do away with the extensions also isnt possible due to said fax/sky boxes and, if you read my original post, my router is on one of the extensions.

Well, lots of people put their routers on extensions, but you didn't mention faxes or Sky boxes. I'm in the same position as you - I have two Sky boxes and a fax machine on my home line, and I reduced my line noise and improved performance by fitting a filtered faceplate on the master socket. I ran my router directly from the ADSL output from the faceplate, and I ran Cat5 ethernet to the computers. All the extensions were then wired to the filtered output on the faceplate, which meant that the Sky boxes, fax and phones on the extensions didn't need filters. Doing this improved my sync speed by nearly 1 Mbps.