TS-790S modification for 9600bps

We must modify in the transceiver because the 9600bd spectrum have
a wide band width.  I made the four modifications the inside of my
KENWOOD TS-790 for receiving and sending 9600bd signal. 

 (1) For transmitter
 (2) For receiver
 (3) For PTT
 (4) For the exchange of FILTER

If you want to do only receiving, you will modify only this (2).
We must extract directly 9600bd RX audio from FM discriminator
of the detector on IF circuit board in the receiver.

The TS790 can be modulated with up to 19200 baud if the following 
four modifications are made.


(1) For transmitter:

  You must connect TX-Audio through a "100k[ohm]" resistor at the
  varicap in VCO unit.

  Open carefully the transceiver case (bottom). Locate the connector 
  "CN31(IF-44-FMD)".  The crystal oscillator is located nearby. 
  This connector is at the rear left side of the large IF-board.

  Solder a 100k[ohm] resistor to the tip of a new shielded cable and
  solder the lead of this resistor at "FMD" to the white wire where
  goes to the signal pin of "CN31".

  Solder a new GRD shielded cable at "GRD" to the black wire where
  goes to the signal pin of "CN31".

  The "CN31" is lined with "L59" and "TC2".


(2) For receiver:

  Solder a new shielded cable at the No.9 pin of "IC8(MC3357P)" and
  solder a new GRD shielded cable at the "L55" if you want to receive
  the 9600 baud signal in Main Window of TS790

  Solder a new shielded cable at the No.9 pin of "IC1(MC3357P)" and
  solder a new GRD shielded cable at the between "C85" and "C86" if
  you want to receive 9600 baud in Sub Window of TS790.

  You had better receive the 9600 baud signal in Sub Window becauce
  we transmit 9600baud signal from Main Window.


(3) For PTT:

  Solder a new shielded cable at No.9 pin of "ACC2 connector"  or
  No.8 pin of "ACC4 connector".


(4) For the exchange of FILTER:

  You must exchange the ceramics filter in Sub Window of TS790 from
  "CFW455F(12.5kHz) to a new "CFW455D(20kHz).  This 55F filter is 
  lined with "IC1(MC3357P)".


[Complement]

After the above four modifications, I connected between TS790 and
TNC241 + TMB965 joinning with one cable as follows.


                  TS-790

                 ||| ||||
             (a) ||| |||| (b)
                 ||| ||||
                 ||| ||||
                 |||  ##  Switch
                 |||  ||
                 |||  || (c)
                 |||  ||
                    ##   DIN 8 pin Jack
                    ##   DIN 8 pin Plug
                  |||||
                  ||||| (d)
                  |||||

                  TMB-965
                     |
                  TNC-241


  (a) Shielded cable soldered with "100k[ohm]" resistor,
      GRD and PTT shielded cable for transmitting.

  (b) Shielded cable for receiving and GRD in Main Window
      and Sub Window.

  (c) Shielded cable after switching.

  (d) Shielded cable for connecting.

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