KENWOOD TH-series HT TNC Interconnection

The  following is a suggested circuit for connecting a packet TNC
to a Kenwood TH-series HT.  Included is the TH-21/31/41,  the TH-
205/215/315/415, and the new TH-25/45 series HTs.

The connections are as follows:

     A  sub-miniature plug is used for receive audio.  The tip of
     this  plug  is audio out;  the sleeve of this  plug  is  the
     common ground for PTT, transmit audio, and receive audio.

     A  miniature stereo plug is used for transmit audio and PTT.
     Connect  the middle "ring" of the plug to the TNC audio  out
     through a 0.2 uf cap (for DC isolation).  Connect the sleeve
     of the plug to the TNC PTT. The plug's tip is unused.

Set  the  TNC audio for 50 to 80 mv audio output into  a  2K  ohm
impedance.