To: mbramwel
Date: Wed, 8 Nov 89 10:24:00 est
Subject: packet mod for TM321
From: rfc
Date: 5 Sep 89 14:37:21 GMT
Sender: news
Msg# TSP Size #Rd Date/Time MsgID From To
2627 BF 1043 2 0904/0022 4650_WA2SNA WM8J ALL
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
Note:I haven't tried this, proceed at your own risk! WA2ISE
SOURCE: The QRZ Windows Ham Radio CDROM |
