Riddick2
18-02-06, 02:36
Καλημέρα σε όλους θα μπορούσε κάποιος να με διαφωτίσει στο θέμα "εξόντωσης θορύβου στην τηλεφωνική γραμμή" που μου δημιουργεί πρόβλημα στην ταχύτητα του Dial-up modem 56k.H τηλεφωνική μου γραμμή είναι πάνω σε PCM δεν μπορώ να βάλω DSL ενώ υπάρχει κάλυψη στην περιοχή μου εξαιτίας του φερέσυχνου το οποίο απο ότι έχω καταλάβει δημιουργεί και θόρυβο "φυσημα" στην τηλεφωνική γραμμή που επηρεάζει πάρα πολύ την ταχύτητα σύνδεσης του modem με τον ΙSP(31,8Kbs).Το συγκεκριμένο modem το δοκίμασα και σε άλλη τηλεφωνική γραμμή χώρις θόρυβο και χωρίς PCM και έπιανε από 44Kbs έως 48 Kbs όπως επίσης δοκίμασα άλλο modem 56 k στην δική μου τηλεφωνική γράμμη κι έπιανε πάλι την ίδια άθλια ταχύτητα 31,2 kbs.'Επειτα από μια σύντομη αναζήτηση στο Ιντερνετ πείστικα πλέον πως ο θόρυβος της γραμμής επηρρεάζει πολύ αρνητικά την ταχύτητα.Βρήκα επίσης ένα κείμενο που θα μπορούσε να βοηθήσει στην κατασκευή ενός "φίλτρου" που ενδεχομένως να βελτιώσει κάπως την ταχύτητα έστω και λίγο.Αξίζει να αναφέρω πως έχω κάνει αμέτρητα παράπονα στον ΟΤΕ αλλά με γράφει κανονικά....Κλασικά όπως πάντα ακομά και μετά την εξαπάτηση για την DSL κάλυψη.Παραθέτω το παρακάτω κείμενο επειδή δεν το πολυκατάλαβα κάτι λέει και για BBS αλλά αν κάποιος ποθ κατέχει την ορολογία καλύτερα απ'ο μένα ας με διαφωτίσει για να μπορέσω να κατασκευάσω το φίλτρο!Όλες οι χρήσιμες ιδέες καλοδεχούμενες!Ευχαριστώ προκαταβολικά.
OK, what you' ll need from Radio Shack:
1 #279-374 Modular line cord if you don't already have one. You
won't need one if your phone has a modular plug in its base.
$4.95
1 #279-420 Modular surface mount jack (4 or 6 conductor) $4.49
1 #271-1720 Potentiometer. This is a 5k audio taper variable
resistor. $1.09
1 #272-1055 Capacitor. Any non-polarized 1.0 to 1.5 uf cap
should do. Paper, Mylar, or metal film caps should be used,
although #272-996 may work as well. (272-996 is a non-polarized
electrolytic cap) $.79
1 100 ohm resistor - quarter or half watt. $.19
1 #279-357 Y-type or duplex modular connector. Don't buy this
until you've read the section on connecting the Noise Killer
below. (A, B,or C) $4.95
First off, open the modular block. You normally just pry them
open with a screwdriver. Inside you'll find up to 6 wires. Very
carefully cut out all but the green and red wires. The ones
you'll be removing should be black, yellow, white, and blue.
These wires won't be needed and may be in the way. So cut them
as close to where they enter the plug as possible.
The other end of these wires have a spade lug connector that is
screwed into the plastic. Unscrew and remove that end of the
wires as well. Now, you should have two wires left. Green and red.
Solder one end of the capacitor to the green wire. Solder the
other end of the capacitor to the center lug of the
potentiometer (there are three lugs on this critter). Solder
one end of the resistor to the red wire. You may want to
shorten the leads of the resistor first. Solder the other end
of the resistor to either one of the remaining outside lugs of
the potentiometer. Doesn't matter which.
Now to wrap it up, make a hole in the lid of the mod block to
stick the shaft of the potentiometer through. Don't make this
hole dead center as the other parts may not fit into the body
of the mod block if you do. See how things will fit in order to
find where the hole will go. Well, now that you've got it built
you'll need to test it.
First twist the shaft on the potentiometer until it stops. You
won't know which way to turn it until later. It doesn't matter
which way now. You also need to determine where to plug the
Noise Killer onto the telephone line. It can be done by one of
several ways:
A. If your modem has two modular plugs in back, connect the Noise
Killer into one of them using a line cord. (a line cord is a
straight cord that connects a phone to the wall outlet. Usually
silver in color)
B. If your phone is modular, you can unplug the cord from the back
of it after you're on-line and plug the cord into the Noise
Killer.
C. You may have to buy a Y-type modular adaptor. Plug the adaptor
into a wall outlet, plug the modem into one side and the Noise
Killer into the other.
***END OF ORIGNAL FILE***
ADDITION TO ORIGNAL FILE - 2/29/88 - Mike McCauley - CIS 71505,1173
First, a personal recomendation. _THIS WORKS!!!_
I have been plagued with noise at 2400 for some time. I went
round and round with Ma Bell on it, and after they sent out
several "repair persons" who were, to be kind, of limited help
in the matter, I threw in the towel. I saw this file on a board
up east a few days ago, and thought I'd bite.
Threw the gismo together in about 10 minutes, took another five
to adjust the pot for best results on my worst conection, and
guess what? No more worst connecion!
A few pointers:
1) The pot need not be either 5K or audio taper.
I used a 10K 15 turn trim pot. Suggest you use what is handy.
2) I used 2MFD's of capacitance (two 1MFD's in parallel) Two R.S.
p/n 272-1055 work fine. Remember that about 90 Volts will
appear across red & green at ring, so the caps should be rated
at 100VDC+.
3) I ended up with a final series resistance value (100 ohm + pot)
of 2.75K. I speculate that one could probably use 2MFD and a
fixed 2.7K resistor and do the job 90% of the time. The
adjustment of the pot is not very critical. Changes of +/- 1K
made little difference in the performance of the circuit.
Hope it works as well for you as it did for me.
Mike McCauley
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^
2nd ADDITION TO ORIGNAL FILE - 2/6/89 - Rich Appel - Philadelphia, PA.
Visual CIRCUIT DIAGRAM:
?????????????????????????????????????????????????? ????????????????????????????
? ?
? ?
? DUPLEX JACK ?
? -OR- ==============\=================== MODEM ?
? 2ND WALL JACK \phone cord ?
? ETC. ?
? | ?
? | /phone cord ?
? |========/===================== MODULAR JACK ?
? | | ?
? | | ?
? ============================ RED WIRE | |===== GREEN WIRE ==== ?
? | | ?
? | | ?
? | | ?
? | 1 - 2.7 K OHM VARIABLE RESISTOR NON-polarized | ?
? ===== RESISTOR ======= "POT" ===== Capacitor == ?
? 5-10 K OHM 1-2 Mfd ?
? ?
? ?
?????????????????????????????????????????????????? ????????????????????????????
3RD ADDITION TO ORIGINAL FILE 1/24/92 Michael Thompson N2NLQ
Voorhees NJ
This circuit appears to be correct.
Another option you may wish to consider, is one of direct installation into
your telephone line. This can be acomplished by finding the wiring block
for your phone line. Once you've located it, you should be able to
determine where the red and green wires connect, and make the apropriate
connections.
This setup is more cost effective than buying plugs and jacks.
1. Make sure the phone cable running between your PC and the wall jack is
in good condition and made of high quality materials. If you can get a
shielded line or a line with a "level" rating you'll be in good shape.
All of the cables we use are level 3.
2. Make sure the phone cable doesn't run close to electrical applicances
if possible. The noise created by this could be sufficient to cause you
problems.
3. If you use an external modem, make sure that the cable between the
modem and the computer is firmly connected and of sufficient quality to
carry data at high speeds. If you own a 2400 baud modem you don't need
to worry as much as someone who has a 28.8 baud modem
OK, what you' ll need from Radio Shack:
1 #279-374 Modular line cord if you don't already have one. You
won't need one if your phone has a modular plug in its base.
$4.95
1 #279-420 Modular surface mount jack (4 or 6 conductor) $4.49
1 #271-1720 Potentiometer. This is a 5k audio taper variable
resistor. $1.09
1 #272-1055 Capacitor. Any non-polarized 1.0 to 1.5 uf cap
should do. Paper, Mylar, or metal film caps should be used,
although #272-996 may work as well. (272-996 is a non-polarized
electrolytic cap) $.79
1 100 ohm resistor - quarter or half watt. $.19
1 #279-357 Y-type or duplex modular connector. Don't buy this
until you've read the section on connecting the Noise Killer
below. (A, B,or C) $4.95
First off, open the modular block. You normally just pry them
open with a screwdriver. Inside you'll find up to 6 wires. Very
carefully cut out all but the green and red wires. The ones
you'll be removing should be black, yellow, white, and blue.
These wires won't be needed and may be in the way. So cut them
as close to where they enter the plug as possible.
The other end of these wires have a spade lug connector that is
screwed into the plastic. Unscrew and remove that end of the
wires as well. Now, you should have two wires left. Green and red.
Solder one end of the capacitor to the green wire. Solder the
other end of the capacitor to the center lug of the
potentiometer (there are three lugs on this critter). Solder
one end of the resistor to the red wire. You may want to
shorten the leads of the resistor first. Solder the other end
of the resistor to either one of the remaining outside lugs of
the potentiometer. Doesn't matter which.
Now to wrap it up, make a hole in the lid of the mod block to
stick the shaft of the potentiometer through. Don't make this
hole dead center as the other parts may not fit into the body
of the mod block if you do. See how things will fit in order to
find where the hole will go. Well, now that you've got it built
you'll need to test it.
First twist the shaft on the potentiometer until it stops. You
won't know which way to turn it until later. It doesn't matter
which way now. You also need to determine where to plug the
Noise Killer onto the telephone line. It can be done by one of
several ways:
A. If your modem has two modular plugs in back, connect the Noise
Killer into one of them using a line cord. (a line cord is a
straight cord that connects a phone to the wall outlet. Usually
silver in color)
B. If your phone is modular, you can unplug the cord from the back
of it after you're on-line and plug the cord into the Noise
Killer.
C. You may have to buy a Y-type modular adaptor. Plug the adaptor
into a wall outlet, plug the modem into one side and the Noise
Killer into the other.
***END OF ORIGNAL FILE***
ADDITION TO ORIGNAL FILE - 2/29/88 - Mike McCauley - CIS 71505,1173
First, a personal recomendation. _THIS WORKS!!!_
I have been plagued with noise at 2400 for some time. I went
round and round with Ma Bell on it, and after they sent out
several "repair persons" who were, to be kind, of limited help
in the matter, I threw in the towel. I saw this file on a board
up east a few days ago, and thought I'd bite.
Threw the gismo together in about 10 minutes, took another five
to adjust the pot for best results on my worst conection, and
guess what? No more worst connecion!
A few pointers:
1) The pot need not be either 5K or audio taper.
I used a 10K 15 turn trim pot. Suggest you use what is handy.
2) I used 2MFD's of capacitance (two 1MFD's in parallel) Two R.S.
p/n 272-1055 work fine. Remember that about 90 Volts will
appear across red & green at ring, so the caps should be rated
at 100VDC+.
3) I ended up with a final series resistance value (100 ohm + pot)
of 2.75K. I speculate that one could probably use 2MFD and a
fixed 2.7K resistor and do the job 90% of the time. The
adjustment of the pot is not very critical. Changes of +/- 1K
made little difference in the performance of the circuit.
Hope it works as well for you as it did for me.
Mike McCauley
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^
2nd ADDITION TO ORIGNAL FILE - 2/6/89 - Rich Appel - Philadelphia, PA.
Visual CIRCUIT DIAGRAM:
?????????????????????????????????????????????????? ????????????????????????????
? ?
? ?
? DUPLEX JACK ?
? -OR- ==============\=================== MODEM ?
? 2ND WALL JACK \phone cord ?
? ETC. ?
? | ?
? | /phone cord ?
? |========/===================== MODULAR JACK ?
? | | ?
? | | ?
? ============================ RED WIRE | |===== GREEN WIRE ==== ?
? | | ?
? | | ?
? | | ?
? | 1 - 2.7 K OHM VARIABLE RESISTOR NON-polarized | ?
? ===== RESISTOR ======= "POT" ===== Capacitor == ?
? 5-10 K OHM 1-2 Mfd ?
? ?
? ?
?????????????????????????????????????????????????? ????????????????????????????
3RD ADDITION TO ORIGINAL FILE 1/24/92 Michael Thompson N2NLQ
Voorhees NJ
This circuit appears to be correct.
Another option you may wish to consider, is one of direct installation into
your telephone line. This can be acomplished by finding the wiring block
for your phone line. Once you've located it, you should be able to
determine where the red and green wires connect, and make the apropriate
connections.
This setup is more cost effective than buying plugs and jacks.
1. Make sure the phone cable running between your PC and the wall jack is
in good condition and made of high quality materials. If you can get a
shielded line or a line with a "level" rating you'll be in good shape.
All of the cables we use are level 3.
2. Make sure the phone cable doesn't run close to electrical applicances
if possible. The noise created by this could be sufficient to cause you
problems.
3. If you use an external modem, make sure that the cable between the
modem and the computer is firmly connected and of sufficient quality to
carry data at high speeds. If you own a 2400 baud modem you don't need
to worry as much as someone who has a 28.8 baud modem