Lprint #03 19 мая 1997

Железо

Iron - Finalization of the modem - relyushka.

 Iron --==< Refinement modem >==-- 05


(C) Hamer MDM 221-8365

 I welcome all readers of the new dial-up newspaper LPRINT.YA 
want talk about finalizing the C-DOS modem, called the people 
Relyushka. So, on board modem is 1 megohm resistor, which 
creates pressure in the line for what would be the server 
responds to zvonok.Tak here, if it decreases, then the server 
will respond better to the challenge Subscriber / I is 500 k /, 
but the quality will deteriorate communication. For that would 
not happen, you need at a time when the "tube" on the modem is 
raised - to disable this rezistor.Etim and engaged 
Relyushka.Risunok shows a fragment of boards, where there is a 
socket for telephone line: 


       \ / O

                                           Vypayany resistor

                                           want to

                                           disconnect

                               o


                 Relyushka

                 The board

                     o o

                    o o o


 View from the side o o
 Boards o o o
 / It was / second Relyushka

                                  view from the findings

If Relyushki refuse to operate together, then they will need to 
bridge the series and powered by 12 volts. So, for example, is 
made in Lam'y: 


     Cut the track from the +5 V / such a long /


                       Serial connection Relyushek

     o o

  \ / O o o <-
   x between the relay and transformer

                       a diode, which must vypayat


            o o

           o o o At Cutter

 +12


 Now the theory: the second Relyushka working on breaking the 
chain, ie in the initial state / when the "tube" to put or her 
contacts in the circuit resistors are closed and so it is 
enabled. When picked up tubes - she works with Relyushkoy on 
the board and breaks resistor chain, which now does not spoil 
ties.  Relyushka set is the same as on the board: REF 49 with 
the supply voltage 6V. 

WW: Thank you very much Hamer'u for its refinement, I hope now 
problemma with removal of the modem pipe, will disappear. By 
the way rumor has it that there is a scheme for "recognition" 
signal from the noise of telephone lines during the 
transmission of information. Maybe I am somewhat well 
formulated, but I think the idea is clear. Would love to see 
this scheme / da, and other useful improvements / the pages of 
our newspapers.