To: mbramwel@uwo.ca
Date: Wed, 8 Nov 89 10:24:00 est
Subject: packet mod for TM321
From: rfc@briar.philips.com (Robert Casey;6282;3.57;$0201)
Date: 5 Sep 89 14:37:21 GMT
Sender: news@philabs.Philips.Com

 Msg# TSP  Size #Rd Date/Time MsgID        From   To
  2627 BF   1043   2 0904/0022 4650_WA2SNA  WM8J   ALL@ALLBBS
   Sb: TM231PACKETMOD

    THE FOLLOWING IS AN EASY MOD TO SQUELCH THE AUDIO AT MIC PIN 6 FOR
    TNC'S

        WITHOUT TRUE DCD:  OBTAIN FROM KENWOOD A 2SD1757(K) (SURFACE
MOUNT TRANSISTOR).  INSTALL EMITTER TO MIC PIN 8, COLLECTOR TO
MIC PIN 6, AND JUMPER FROM BASE TO THE UNUSED PIN ON CONNECTOR
202. USING THE UNUSED PIN RATHER THAN RUNNING THE JUMPER TO THE
        MOTHER BOARD PRESERVES THE PLUG IN FEATURE OF THE FRONT PANEL.
        CONNECT ONE END OF A 4.7 K RESISTOR (I USED A 6.8 K) TO THE
        MUTE LINE (IC 5 PIN 7), AND CONNECT THE OTHER END TO THE UNUSED
        PIN OF CONNECTOR 4, WHICH MATES WITH CONNECTOR 202.  THIS NEW
        CIRCUIT IS A CLOSE COPY OF THE AF MUTE CIRCUIT THAT SQUELCHES
        THE RX AUDIO AT THE SPEAKER. IT WORKS PERFECT WITH MY PACCOMM
        MICROPOWER 2.  THE HARDEST PART OF THE MOD IS REMOVING THE
        LOCKING RING AROUND THE MIC CONNECTOR. I USED A MODIFIED TABLE
        FORK! GOOD LUCK.

        0241z, 939 msgs, #2643 last @KD6TH-4 MailBox>

Note: I haven't tried this, proceed at your own risk! WA2ISE