![]() |
|
|
#1 |
|
Guest
Posts: n/a
|
telephone lines
Hi ------
Just a simple question..... How a telephone tx rx works???...I mean how 1 pair of conductor in the telephone can trasmitt and recive simultaneously audio signals......????(if I understood well the pair trasmitt and at the same time it recives signals) How a single couple of wire tx and rx????? many thanks jac |
|
|
|
#2 |
|
Guest
Posts: n/a
|
Re: telephone lines
<> wrote in message news:1177587301.389146.89810@r35g2000prh.googlegro ups.com... > Hi ------ > Just a simple question..... > How a telephone tx rx works???...I mean how 1 pair of conductor in > the > telephone can trasmitt and recive simultaneously audio > signals......????(if I understood well the pair trasmitt and at the > same time it recives signals) > How a single couple of wire tx and rx????? > many thanks > jac Its actually very easy to achive. When I was a child I wired two telephone handsets together to make an intercom. The two carbon transmitters And the two earpieces and a battery were all wired in series. Yes it worked but not very well. You could hear your own voice in the receiver just as loud as the other party, telephone engineers call this excessive sidetone. The trick is to use a transformer arrangement or an electronic circuit that cancels your own voice to a large extent, a small amount of sidetone is desirable. Its all connected with correct impeadence matching, Google the word "hybrid" in this context. -- Graham. %Profound_observation% |
|
![]() |
| Thread Tools | |
| Display Modes | |
|
|
< Windows Help - MS Office Help - Hardware Support >
| New To Site? | Need Help? |