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Microfilters are killing my max!

crimsone
Grafter
Posts: 317
Registered: 15-08-2007

Microfilters are killing my max!

Smiley Stablerate is 7000. Nothing wrong with that as it's correct - my line can support a very fast speed. SNR margin is reasonable when the phone isn't in use anyway.

The handset is quite a normal bog-standard corded handset that's about 6 years old. The filters are ok with it for a few days, and so I can't really see why the handset would wear them out like that. I'll consider the possibility though.

The box on the wall is of the newish type with a detatchable bottom frontpanel. The frontpanel actually plugs into the mastersocket and feeds the line through to the socket on the panel. As such, the socket on the panel is effectively the master. There is no extension wiring in the box. there is however a 3 meter extension from the filter to the phone, and a 10 meter modem cable (not an extension) from the filter to the router. Both are brand new.
22 REPLIES
crimsone
Grafter
Posts: 317
Registered: 15-08-2007

Microfilters are killing my max!

I have one of the strongest lines in my area. Up untill today, and for the last 9 days, I've been synching at the maximum possible rate of 8 meg.

Early in the 10 days, I had a problem with the phone causing my router to loose synch. and so first thin the next day, I replaced the microfilters with new ones, and the problem was solved. That is, it was solved for about 3 days. At that point, I started getting the problem again - only the once before I checked the line and discovered the hiss. I disconnected to prevent damage to my chances of higher speeds, and half an hour later I put a brand new original BT microfilter on my line, which solved the problem once more.

However, today I find that myy router re-synched while I was asleep, and has also done so twice today as a result of my responding to the fact that my phone was ringing (ie, picking it up to answer it). The hiss is back while the phone is being used (not when it's off the hook - just when I'm talking on it). From previous symptoms, it's clear to me that the microfilter has worn out yet again in a matter of days!

The SNR margin on my line while synched at 8 meg fluctuated between 6dB and 11 dB (with rare drops to 5.9 and rare increases to 12.2) - ther's clearly margin to spare on it in normal operation. It's just these darned microfilters!!! At this rate they're costing a fortune.

I'm now connecting at just 5.5meg, and I undoubtedly still have this hiss on the line while in the middle of a phone call due to the microfilter destroying itself, and further reduction is immanent should I not be able fix this problem. It's only the router and one normal house phone on the line.

Any ideas why this is happening anyone? what can I do?
N/A

Microfilters are killing my max!

Have you tried connecting your router to the main BT plug socket to test?

Have you considered it might be your phone causing the problem. Its a long shot, I know, but you could try another phone instead of your current handset. Just to rule it out. (you never know)

Have you checked your stablerate to see what that says aswell?
N/A

Microfilters are killing my max!

Have you considered demonic possession of your Filters.

Ive never had filter problems but if you havnt already try a new filter one more time.

Get one from Maplins or something (thats where I bought mine)

If it happens again then, Im out of ideas but Im sure the guys around here will be able to help better than me.
kjaerligkatt
Grafter
Posts: 411
Registered: 02-09-2007

Microfilters are killing my max!

I've seen a similar problem @ my parents. I finally tracked it down to the filters - BT branded ones bought from Maplin.

I replaced them with decent filters, and they've never had the problem since (this after 4 of the BT filters fried)!

Neil
crimsone
Grafter
Posts: 317
Registered: 15-08-2007

Microfilters are killing my max!

Any recommendations for decent filters, price approximation, and a shop where I can walk in to buy them? Smiley

(thanksfor the help so far!)
kjaerligkatt
Grafter
Posts: 411
Registered: 02-09-2007

Microfilters are killing my max!

In terms of plug in filters, I don't think you can beat the Excelsus Z420UKP2J, but I do not know where you can 'walk in and buy one'. Easy to find online though - should cost around 6 quid.

I would, however, take an entirely different route. Assuming you have a modular master socket, I'd add an NTE5 ADSL 1.0 to completely separate the ADSL & POTS signal. You then will not require ANY filters on the extension sockets. This is the best solution providing you can either put your ADSL modem/router close to the NTE5, or easily run a cable between the two.

Neil
Plusnet Staff
Plusnet Staff
Posts: 12,169
Thanks: 18
Fixes: 1
Registered: 04-04-2007

Microfilters are killing my max!

Hi,

I don't think I can recall a case of microfilters wearing out that quickly, certainly not more than once. It's difficult to suggest what could be doing it. A faceplate is probably a good idea, and would be curious as to whether this fixes is.
N/A

Microfilters are killing my max!

Quote
there is however a 3 meter extension from the filter to the phone, and a 10 meter modem cable (not an extension) from the filter to the router.


Would it be possible to instead connect the router directly using a shorter modem cable (say, 1 meter or less) or using ethernet cable or WiFi to your pc?

Since you have the new style socket, I'd try a replacement face plate with built in ADSL filter. If that doesn't work, try changer the phone, router, or both, as filters shouldn't die that quickly.
kjaerligkatt
Grafter
Posts: 411
Registered: 02-09-2007

Microfilters are killing my max!

Quote
Hi,

I don't think I can recall a case of microfilters wearing out that quickly,


There are a lot of very badly designed microfilters out there right now. Just open up a few, and see how many have the ring wire just passed directly through, rather than provising their own ring capacitor. This is one of the main reasons for problems with difficult loads, such as some cheap DECT phones.

Neil
oliverb
Grafter
Posts: 606
Registered: 02-08-2007

Microfilters are killing my max!

FWIW I had a problem with audible hiss a while back and it turned out to be a bad BT junction box.

I can't think what the deal with the filters is though, it's not like there's much in there to wear out, just a few passive components.
sloany
Grafter
Posts: 153
Registered: 08-06-2007

Microfilters are killing my max!

I had a similar problem, when my phone rang it also sent my router out of sync, after replacing microfilters ect i borrowed a neighbours phone and that cured the problem. must have been a faulty phone.
crimsone
Grafter
Posts: 317
Registered: 15-08-2007

Microfilters are killing my max!

Fon from the advice graciously given here, I'm going to try the following...

As my computer is in the living room, and requires a minimum of 5 meters of cable to reach my only phone socket in the hall nex to the front door, I'm going to install the ADSL faceplate/splitter on the masterbox, and using Cat5e cable in the IDC connectors, run an extention on the filtered (phone) side to the living room. On the same cable, using the green set, I'll carry the unfiltered (ADSL) side.

This will be connected into a surface mount wall box with a double extension plate. One will be for the phone, and the other for the ADSL. I have an RJ12 to RJ11 adaptor for the wallbox socket.

This leaves only the modem cable between the wallbox and the PC to pick up interferance. It's a shorter length to travel, but I still want to improve it. As I don't have an RJ12 connectors, I intend to wire up a Cat5 cable with an RJ11 plug on either end. This leaves me requiring two pieces of information...

On the NTE 2005 faceplate, the unfiltered ADSL signal is carried on two extention wires, A, and B. Does the polarity of these terminals matter, and which terminals would I connect them to in a six connection (2 blocks of three IDC connectors) extension socket?

On an RJ11 connector, which pins carry the ADSL signal?

Many thanks...
crimsone
Grafter
Posts: 317
Registered: 15-08-2007

Microfilters are killing my max!

No matter. The ADSL signal connects to an RJ12 signal just as the phone line would.

The pins on an RJ11 that carry the signal are the middle two.

Polarity either doesn't matter, or altyernatively, I made the right guess Smiley

I got an immediate synch speed improvement after fitting all this, and it's now the full 8128 again. There's no noise at all on the phone, and the SNR margin reported by my router is now fluctuating between 3.7 and 7.4

Lets see what happens over the next few days. Fingers crossed that the noise doesn't return!
Mand
Grafter
Posts: 5,560
Thanks: 1
Registered: 05-04-2007

Microfilters are killing my max!

Here's hoping you've fixed it, let us know in a few days! Smiley