CAT (Computer Aided Transmitter) system operations for the Kenwood TS-50

After several researches on the WEB and with the help of André VE2FAB, Michel VE2TLM and Réal VE2DSK here is very easy way to use your radio with the CAT mode. The CAT system will allow you to change the frequency or mode on the TS-50 from your computer with the help of a software and a RS-232 Interface.
For this the Kenwood model TS-50 need two modules the IF-232C Interface Unit and the IF-10D Interface Unit to be able to operate with the CAT system.  These two devices are now obsoleted, Kenwood don't sell them no more, even the TS-50 is no longer avalable. Also the price of these two units were very expensive, the IF-232C (239$) and the IF-10D (169$).    
First, here is a small explanation for IF-232C and the IF-10D. The IF-232C is communicating all the informations from the software in your computer to your TS-50, for the non-tecnitian, the electricity in your computer can read only logical signals 1 or 0, +5v. or 0v. But the radio is working with 12v. so how will they communicate together, the answer is via the communication port that is present in all computer by the name COM1, it will connect the radio via the RS-232 mode. But the IF-232C is inverting the signal because of the four optocouplors, so the signal have to be inverted again, we use the IF-10D to do it.
Here is a very easy and also low cost way to operate your TS-50 from your computer. This project cost me around 25$ Canadian.
Parts you should have before starting the project :
1 serial cable extension (DB-9 male to DB-9 female)
1 connector to go inside the radio
1 Max232CPE with the capacitors
1 box
Diagram of the project by Michel VE2TLM :

The new connector will be hooked to the CN6 inside the radio.

The CN6 with the bottom cover removed.

The CN6 with the radio cover.

This is the small connector you will need to connect the Max 232 to the radio.
Connection bettween "CN6" and the "MAX232 RS232 Breadboard Adapter"
                              #1 CTS      Goes To      CTDT
                              #2 RTS     Goes To      RTDS
                              #3 RXD     Goes To      RX 3
                              #4 TXD     Goes To      TX 4
                              #5 5 V       Goes To      U+
                              #6 GND     Goes To      GN
Available from Digikey, this is the number :

You must buy 10 of them but they are very low cost (1$) and the terminals (3$)

Now for the RS-232 interface, you have to solutions.
First one :
You have to buy the Max232CPE and the capacitors, after makes one PCB and apply all the components.
The Second solution is very easy :
From Ebay you can purchase a
MAX232 RS232 Breadboard Adapter for Basic/PIC/68HC/8051
all completed its around 15$ Canadian.

All parts are ready for the box.

1: I made a hole in the box the hook it to the side of the radio.
2: With a round file make space for the two wires on each side.
3: You can solder the wires directly to the PCB or apply a header on the PCB.
4: The CONN HOUSING ZH 6 POS 1.5MM connector.
5: With a female header, is easier to work.
Note : I apply hot glue to protect the wires.

The Max232 is hooked to the DB-9 cable extension.

The interface his now in the box, I apply the female heather at the other end of the wire.

The job is comleted.

A few operation tips.
If you use Ham Radio Deluxe, this software will detect automaticly the radio and the communication port.
For MixW et N1MM software the configuration should be like this :
Port : Com1
Baud rate : 4800
Data Bits : 8
Parity : None
Stop Bits : 2
RTS : Always On
DTR : Always On
Have fun,
72' & 73' de Serge VE2HLS