
                     YAESU & HEATH RS-232 INTERFACE
 
                                                            DB-25S (DB-9S)
   
                        Ŀ          7     (5)
                                                      
                                   MAX-232           ſ     6
                                + Ŀ  
              78L05        ĴĴ1    16             5     (8)
             Ŀ           +                       
     +12V ĴI   OĴĴ2    15Ŀ             4     (7)
               G     +                 ſ   RxD 
                  Ĵ3    14 3     (2)
                             +               TxD
                          ĴĴ4    13 2     (3)
                                       
               ſ     ſ  Ĵ5    12Ŀ             1
                              +                
                            ĴĴ6    11Ŀ  
                                             
                                  7    10               C.A.T.
                           ſ                
                                   8     9     3 (S.IN)
                                     
                                               2 (S.OUT)
                                             
                                                         1 (GND)
                                                        
                                                       ſ

I received the above layout via the Internet.

I will not give any guarantee that it will work and
that it does not damage any hardware.

Here are some additional hints:

- read the drawing carefully, bridges and connections
  are marked differently

- capacitors could be 22 uF / 16V tantal,
  the c. at the output of the 78L05 100 uF,
  watch for correct polarity !

- pins 7-8 and 9-10 of the MAX-232 could be connected pairwise

- for the YAESU FRG-100: connect pin 11 of the MAX-232
  with a resistor of 5k6 to the ground or you will not
  be able to receive data from the FRG-100 !

- I had to connect pins 4-5-8 together, and pin 6 to pin 20 on
  the D-25 plug, to make it work with my RS232 port. I don't have
  the pinout for the D-9 version of the RS232 plug, but it should 
  not be very difficult to get that info.

  This was not in the original posting I received via the
  Internet.

  Thor.

  e-mail     : thunder@ibm.net

  snail mail : Thor Andersen
               P.O.Box 9070
               N-3002 Drammen
               Norway.

  Phone      : +47 32 88 47 31
