APPENDIX E


 TNC-2 MODEM HEADER PARTS FOR 300 BAUD HF PACKET OPERATION


         This refers to the demodulator header U19.


                  PIN                  PIN

                  1 -----  N/C   ----- 16


                  2 -------|(--------- 15
                          0.022 uF

                  3 -----/\/\/\/\----- 14
       15 K for Fc = 2200 Hz,  22 k for Fc = 1700 Hz

                  4 -----/\/\/\/\----- 13
                           180 K

                  5 -------|(--------- 12
                         0.0047 uF

                  6 -------|(--------- 11
                          0.01 uF

                  7 -----/\/\/\/\----- 10
                           100 K

                   8 -----/\/\/\/\----- 9
                           750 K