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IC-746 FAQ
5
Computer Control
5.1
How do I wire the IC-746 up for computer control?
5.2
What cables do I need?
5.3
What are CT-17, OPC-478, OPC-662 all about?
The IC-746 is computer controllable through a serial interface, but it is not RS-232. This is
both good and bad. Bad, because you can't just plug it straight into your computer (wrong
voltages, etc...). Good, because you can control four separate rigs with the same serial line.
Therefore, to connect the IC-746 to a computer requires some interfacing. Icom made three:
the CT-17, OPC-478, and OPC-662.
The CT-17 is the full boat. Versatile, it will allow 4 rigs to be controlled by a single RS-232
serial line. It's also the most expensive option and requires external power.
If all you want to do is connect up a single rig, then Icom's WWW site lists the OPC-662
remote PC control cable as the official part. If you can find it, then great. Most people can't.
Instead, many hams have successfully used the OPC-478 PC cloning cable. It's less than half
the cost of the CT-17. However, it is very short (1 ft ?) and will require a 1/8 inch stereo to
mono plug adapter for use with the IC-746.
When you buy the RS-746 remote control software from ICOM, it comes with a single rig
cable (OPC-662 or OPC-478?).
W2ENY sells a complete CT-17 clone and a single rig cable. They're both more complete
package than Icom's, coming with cables and software resources on a CD-ROM. They're
also cheaper. You can find out more at:
http://www.geocities.com/w2eny/civ/
http://www.geocities.com/w2eny/icom_cable/
You could purchase the nearly universal rig interface, the RigBlaster, from the folks at West
Mountain Radio. It does a lot more than simply computer control, and is adaptable to other
manufacturers (for a price).
http://www.westmountainradio.com/
The Raymond Sarrio Company also make transceiver to computer interfaces:
http://www.sarrio.com/sarrio/w1gee.html
There's really not that much circuitry in "simple" interface cables, and many have
homebrewed them for as little as $10.
Supposedly, the November 2000 issue of QST
has a suitable design (with feedback in the January 2001 issue). On-line circuit diagrams
based on the QST article appear at:
http://www.ambersoft.com/Amateur_Radio/Icom_Interface.jpg
and
http://www.qsl.net/civ_commander/interface.jpg
Page 59 of 113
2003-02-08