TS440S.8

TS-440 INFO (1/4)
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Hints on the Kenwood ts440
Brian Kantor, WB6CYT.
The TS440 is nice. Here's what I've found out about it that isn't in the
operting manual( in some random order ):
Diode Options:
There are a bunch of configuration options controlled by clipping or inserting
diodes on the back :Aadjust the Mic Gain on FM - there is a seperate tweaker
for that).
Serial Interface
The TS440 has a serialASCII interface option.  You have to insert two chips
into sockets on the back of the control unit circuit board to take advantage
of this.  IC54 is an 8251A Uart, and IC55 is a CD4040 divider.  These chips
are available from Kenwood together with an interface manual, or you can buy
them at your local chip shop for about $6.00 or so.  When inserted, the
transceiver speaks 4800 baud ascii in/out the 6-pin DIN connector ACC-1 on the
rear.  The signals are from the 8251, but are inverted in a 74LS04 and RFI
filtered before being brought out to the world.  An interface box with
inverter, RFI filter, power supply, opto-isolator, RS232 level shifters,
CONTINUED IN FILE TS440S.36