Here is how I made a computer interface for my KX3. Following the recommendation of Lance Collister - W7GJ, I
chose the Rigblaster NOMIC. I made some changes from Lance's design.
I did not need computer CW so eliminated the extra opto-isolator. Also, when I purchase the
NOMIC in 2018, I also bought the RJ45 to KX3 mic connector cable. It used RJ45 pins 1,2 and 8 so I set the NOMIC
Also I had a mini-phone plug jumper cable which I did not want to "butcher" by splicing it with the mic connector
so I used a standard RJ45 break-out box to use for interconnections. A short RJ45 jumper is used between the
NOMIC and the breakout box. I installed a stereo 3.5mm mini-phone jack in the breakout box cover which feeds the
KX3 ACC1 jack. The ACC1 jack provides computer control of the KX3. I ran a three-conductor jumper to a RJ45 female
jack to use with the mic cable. I split the PTT line with two wires to connect to my station sequencer to delay
The sequener controls sequencial application of dc power to my preamp, TR relay, keying of transveter and amplifiers
with last step keying the KX3 into transmission. This prevents RF power being applied before the switchover is
Here is a wiring diagram:
Photos will be added, later.
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