Baud rate modifications Modem FSK9601

 receiver modification for 19200 baud
 transmitter modification for 19200 baud

 receiver modification for 38400 baud
 transmitter modification for 38400 baud

 receiver modification for 76800 baud
 transmitter modification for 76800 baud

 receiver modification for 153600 baud
 transmitter modification for 153600 baud

 receiver modification for 307200 baud
 transmitter modification for 307200 baud

 receiver modification for 614400 baud

modifications of old FSK9600 modem
data, ordering etc. of FSK9601 modem

RX19200 9600 for 19200 baud

  1. C13 (1n) replaced by 330pF
  2. R33 (39k) replaced by 22k
  3. R34 (82k) replaced by 47k
  4. C15 (1n) replaced by 470 pF
  5. C12 (100n) replaced by 47 nF
  6. Jumpers: TX 9600 / RX 19200: J5 + J6; (J4 open)
    TX 19200 / RX 19200: J8 + J4; (J6 open)
    TX 38400 / RX 19200: J10 + J3; (J4 and J6 open)
    TX 76800 / RX 19200: J12 + J2; (J4 and J6 open)

TX19200 9600 for 19200 baud

  1. C3 (1n) replaced by 470pF
  2. C2 (1n) replaced by 470pF
  3. C6 (220p) replaced by 100p
  4. Jumpers: TX 19200 / RX 9600: J3 + J8; (J4 + J6 open)
    TX 19200 / RX 19200: J4 + J8; (J6 open)
    TX 19200 / RX 38400: J5 + J8; (J4 + J6 open)
    TX 19200 / RX 76400: J11 + J8; (J4 + J6 open)

RX38400 9600 for 38400 baud

  1. C13 (1n) replaced by 220pF
  2. R32 (27k) replaced by 15k
  3. R33 (39k) replaced by 12k
  4. R34 (82k) replaced by 27k
  5. C15 (1n) replaced by 470 pF
  6. C12 (100n) replaced by 22 nF
  7. Jumpers: TX 9600 / RX 38400: J9 + J6; (J4 open)
    TX 19200 / RX 38400: J8 + J5; (J4 and J6 open)
    TX 38400 / RX 38400: J10 + J4; (J6 open)
    TX 76800 / RX 38400: J11 + J6; (J4 open)

TX38400 9600 for 38400 baud

  1. C3 (1n) replaced by 220p
  2. C2 (1n) replaced by 220pF
  3. C6 (220p) replaced by 47p
  4. Jumpers: TX 38400 / RX 9600: J2 + J10; (J4 + J6 open)
    TX 38400 / RX 19200: J3 + J10; (J4 and J6 open)
    TX 38400 / RX 38400: J4 + J10; (J6 open)
    TX 38400 / RX 76400: J5 + J10; (J4 + J6 open)

RX76800 9600 for 76800 baud

  1. C13 (1n) replaced by 100pF
  2. R32 (27k) replaced by 12k
  3. R33 (39k) replaced by 6k2k
  4. R34 (82k) replaced by 13k
  5. C15 (1n) replaced by 470 pF
  6. C12 (100n) replaced by 10 nF
  7. Jumpers: TX 9600 / RX 76800: J11 + J6; (J4 open)
    TX 19200 / RX 76800: J11 + J8; (J4 and J6 open)
    TX 38400 / RX 76800: J10 + J5; (J4 and J6 open)
    TX 76800 / RX 76800: J12 + J4; (J6 open)

TX76800 9600 for 76800 baud

  1. C3 (1n) replaced by 100pF
  2. C2 (1n) replaced by 100pF
  3. C6 (220p) replaced by 33p
  4. Jumpers: TX 76800 / RX 19200: J2 + J12; (J4 + J6 open)
    TX 76800 / RX 38400: J3 + J12; (J4 + J6 open)
    TX 76800 / RX 76800: J4 + J12; (J6 open)
    TX 76800 / RX 153600: J5 + J12; (J4 + J6 open)

RX153600 9600 for 153600 baud

  1. C17 (100p) replaced by 47 pF
  2. C13 (1n) replaced by 100pF
  3. R32 (27k) replaced by 6k2
  4. R33 (39k) replaced by 3k0
  5. R39 (1k) replaced by 470E
  6. R34 (82k) replaced by 6k2
  7. C15 (1n) replaced by 470 pF
  8. C12 (100n) replaced by 2n2
  9. Jumpers: TX 9600 / RX 153600: J13 + J6; (J4 open)
    TX 19200 / RX 153600: J13 + J8; (J4 and J6 open)
    TX 38400 / RX 153600: J13 + J10; (J4 and J6 open)
    TX 76800 / RX 153600: J12 + J5; (J4 and J6 open)
    TX 153600 / RX 153600 J14 + J4; (J6 open)
    TX 307200 / RX 153600: J12 + J5; (J4 and J6 open)

TX153600 9600 for 153600 baud

  1. C3 (1n) replaced by 47pF
  2. C2 (1n) replaced by 47pF
  3. R13 (1k) replaced by 470E
  4. R12 (1k) replaced by 470E
  5. C6 (220p) replaced by 47p
  6. Jumpers: TX 153600 / RX 38400: J2 + J14; (J4 + J6 open)
    TX 153600 / RX 76800: J3 + J14; (J4 + J6 open)
    TX 153600 / RX 153600: J4 + J14; (J6 open)
    TX 153600 / RX 307200: J5 + J14; (J4 + J6 open)

RX307200 9600 for 307200 baud

without changeing the xtal osc, max. TX baud rate is 153600 baud!
  1. C17 (100p) replaced by 27 pF
  2. C13 (1n) replaced by 100pF
  3. R32 (27k) replaced by 3k0
  4. R33 (39k) replaced by 3k3
  5. R39 (1k) replaced by 220E
  6. R38 (1k) replaced by 470E
  7. R34 (82k) replaced by 6k8
  8. C15 (1n) replaced by 220 pF
  9. C12 (100n) replaced by 2n2
  10. Jumpers: TX 19200 / RX 307200: J15 + J8; (J4 and J6 open)
    TX 38400 / RX 307200: J15 + J10; (J4 and J6 open)
    TX 76800 / RX 307200: J15 + J12; (J4 and J6 open)
    TX 153600 / RX 307200 J14 + J5; (J4 and J6 open)
    TX 307200 / RX 307200: TX 307200 (only possible when changeing xtal osc).

TX307200 9600 for 307200 baud

  1. C3 (1n) replaced by 47pF
  2. R7 (10k) replaced by 4k7
  3. C2 (1n) replaced by 27pF
  4. Quartz oscillator 9,8304 MHz replaced by 39,3216 MHz
  5. R13 (1k) replaced by 220E
  6. R12 (1k) replaced by 220E
  7. C6 (220p) replaced by 27p
  8. Jumpers: TX 307200 / RX 76800: J2 + J14; (J4 + J6 open)
    TX 307200 / RX 153600: J3 + J14; (J4 + J6 open)
    TX 307200 / RX 307200: J4 + J14; (J6 open)
    TX 307200 / RX 614400: J5 + J14; (J4 + J6 open)

TX614400 9600 for 614400 baud

  1. C3 (1n) replaced by 47pF
  2. R7 (10k) replaced by 2k2
  3. C2 (1n) replaced by 15pF
  4. Quartz oscillator 9,8304 MHz replaced by 39,3216 MHz
  5. R13 (1k) replaced by 100E
  6. R12 (1k) replaced by 100E
  7. C6 (220p) replaced by 15p
  8. U4 (DAC TLC7524)  Pin 13 (WR) unsolder, bend up and connect to pin 12 (Ground).
    Jumpers: TX 614400 / RX 153600: J2 + J14; (J4 + J6 open)
    TX 614400 / RX 307200: J3 + J14; (J4 + J6 open)
    TX 614400 / RX 614400: J4 + J14; (J6 open)
 

TXBaud

  

9600

19200

38400

76800

153600

307200*

307200+

614400+

RX 2400

  

J2 + J6

              

RX 4800

  

J3 + J6

J2 + J8

  

note (E)

note (C)

      

RX 9600

  

J4 + J6

J3 + J8

J2 + J10

note (D)

note (B)

      

RX 19200

  

J5 + J6

J4 + J8

J3 + J10

J2 + J12

note (A)

      

RX 38400

  

J9 + J6

J5 + J8

J4 + J10

J3 + J14

J2 + J14

  

J2+J12

  

RX 76800

  

J11 + J6

J11 + J8

J5 + J10

J4 + J12

J3 + J14

J2 + J14

J3+J14

J2+J14

RX 153k

  

J13 + J6

J13 + J8

J13 + J10

J5 + J12

J4 + J14

J3 + J14

J4+J12

J3+J14

RX 307k

  

J15 + J6

J15 + J8

J15 + J10

J15 + J12

J5 + J14

J4 + J14

J5+J12

J4+J14

RX 614k*

    

J15 + J6

J15 + J8

J15 + J10

J15 + J10

J5+J14

    

RX 614k+

    

J13 + J6

J13 + J8

J13 + J10

J5 + J12

  

J3 + J14

J4+J12

RX 1228k+

      

J15 + J6

J15 + J8

J15 + J10

  

J5+J14

J15+J12

*: Xtal oscillator 19,6608 MHz  / +: Xtal oscillator 39,3216 MHz instead of 9,8304 MHz

(A): J14 closed, J7 pad oriented to board center connected to U3 (ROM) Pin 12 (TX153k/RX19k2)

(B): J14 closed, J7 pad oriented to board center connected to U3 (ROM) Pin 7 (TX153k/RX9k6)

(C): J14 closed, J7 pad oriented to board center connected to U3 (ROM) Pin 8 (TX153k/RX4k8)

(D): J12 closed, J7 pad oriented to board center connected to U3 (ROM) Pin 12 (TX76k/RX9k6)

(E): J12 closed, J7 pad oriented to board center connected to U3 (ROM) Pin 7 (TX76k/RX4k8)