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need help with a telephone line filter

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yeto

New Member
Hi,

Let me ask for forgivness in advance if this is not the right place to post this. I know just enough about electronics to be dangerous.

I have a lot of noise on my phone line and I am trying to design a band pass filter to block noise so hopefully my modem will run faster. From what I have been able to find on the internet dialup uses the frequency between 600-3000hz.

The following attached schematic is a design that, I was hoping with my limited knowledge on the subject, would allow the frequency band of 605-3014 to pass through. When I inserted this into the phone circuit I could not get a dial tone. I then tried just a high pass filter with a 4.7 cap connected to the green(+) line followed by a 56 ohm resistor connected in series and then the resistor connected to the red(-) line. This did reduce noise level somewhat but instead of the internet connection being faster it was slower.

Next I tried a low pass filter with a 16 ohm resistor connected to the green(+) wire followed by a 3.3 cap connected in series and then the cap connected to the red(-) wire. The modem would not connect with this setup.

Would anyone have any thoughts, ideas or suggestons as to what I am doing wrong or could you offer some things that I might try.

Where I live cable or dsl is not an option and I cannot afford satellite.

Thanks in advance for any help,
yeto
 

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yeto

New Member
I had the phone line checked by the phone company, and even though they admit there is a lot of noise on the line, they said, by law, it is good enough as long as someone can carry on a conversation.

Thanks for your reply,
yeto
 

Sceadwian

Banned
Find out what law it is and make sure they're not mis interpreting it. If you complain enough they have to fix it.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
I had the phone line checked by the phone company, and even though they admit there is a lot of noise on the line, they said, by law, it is good enough as long as someone can carry on a conversation.
As Bill suggested, you can't filter it, you would just make it even worse.

Certainly in the UK phone companies only guarantee a voice quality line, if that's excessively noisey then they will fix it, but they aren't interested in complaints of poor modem speed, and have no obligation to sort it out.
 

audioguru

Well-Known Member
Most Helpful Member
Isn't it the year 2009 now?
Didn't computers use dial-up about 15 years ago?
Then later 56k modems were used that used very high frequencies?
Then DSL modems were used that are very fast (for phone lines)?
 

Sceadwian

Banned
10-15% of the US still uses dialup Internet.
 

Sceadwian

Banned
Audioguru, I think Canada is near 50%.
 

audioguru

Well-Known Member
Most Helpful Member
Audioguru, I think Canada is near 50%.
Simply look in Google:
1) 7 months ago, 80% of Canadians had broadband internet access.
2) Last year, only 9% of Americans used dialup.

That is why I said that 3rd world countries still use dialup internet access.
 

tcmtech

Banned
Most Helpful Member
Simply look in Goggle:
1) 7 months ago, 80% of Canadians had broadband INTERNET access.
2) Last year, only 9% of Americans used dialup.

That is why I said that 3rd world countries still use dialup internet access.
So what are the other 20% of Canadians using? ;)
And what are the other 91% of Americans using? :)

And statistically about 9% of all Americans are cheap ass's! :D
(My extended family represents about half of that 9%) :(

:p:)
 

Sceadwian

Banned
80% of Canadians had broadband access, not used it.
 

tcmtech

Banned
Most Helpful Member
wait until you have a stormy day and then hook a neon sign or fuel oil igniter furnace transformer to the feed line and then nuke the wires. ;)

Phone line static typically comes from bad connections or moisture inside the wire. BOth are typical of old wire that is near its end anyway.
Either way high voltage will find the weak spot and punch it through and burn it out!

Do it enough times and the company will come to the sad conclusion your wire is old or just worn out and they will have to run new one in!
So many repairs logged in a short time warrants line replacement. :)

Or they catch you and then you have no phone and a big fine for your efforts! :D;):(
 

Nigel Goodwin

Super Moderator
Most Helpful Member
Hi,

Could you guys take a look at the following links and attachment and tell me what you think? It looks like some people have been successful at making a filter that will help with dialup internet speed.

Internet modem dial-up problems

Telephone line noise filter apparatus - Patent 5073924

Some people have used the attached schematics with some success.

Thanks,
yeto
If you think those circuits will help, then try them - you've nothing to lose.

You might even try plugging an ADSL filter in (using the phone output), see if that helps at all.
 
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RODALCO

Well-Known Member
How many phones do you have connected in parrallel with your internet connection ?

Anything connected in parrallel while using the internet will reduce you landline speed.
 

mvs sarma

Well-Known Member
I assume that this noise is only after superimposing the DSL filters at the exchange and Customer premises. . If so, YETO may try with local engineers to get the DSL wedged out for test purpose on either side.
If still noise persists, it is due to cable being leaky or due to power induction.
otherwise, the Central office can oblige a spare set of filters, what they call as port change. It can't be that the Telecom and DSL providers cant solve it.

as rightly pointed out by RODALCO, any phone instrument installed before the splitter is likely to have the DSL noise. we are expected to have telephone instruments only after the splitter, at the phone jack of splitter.
 
Last edited:

mvs sarma

Well-Known Member
I assume that this noise is only after superimposing the DSL filters at the exchange and Customer premises. . If so, YETO may try with local engineers to get the DSL wedged out for test purpose on either side.
If still noise persists, it is due to cable being leaky or due to power induction.
otherwise, the Central office can oblige a spare set of filters, what they call as port change. It can't be that the Telecom and DSL providers can't solve it.
 

RODALCO

Well-Known Member
Try this and see if the noise disappears.

Disconnect all your phones from their sockets and have the computer only using the phone line by itself.

Ensure that the computer modem has a "clean" line.

Do your data transfer and see if the speed improves.

If the noise disappears the problem is with one of your phones.

If noise or low speed still persists, you may have a dodgy, corroded connection and the problem is most likely there or it is on the Telco side.
 
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