IC7100 CAT connection for remoterig

If you want to operate remotely with your PC connected to the RRC control side (RRC-CP for the rest of article), you need to add a CAT interface throught the RRC radio (RRC-R for the rest of article) and the IC7100 radio.

The most simple way, but also the most expansive $$$ one, is to buy the ICOM CT-17 C-IV interface.

The other possibility is to buy a simple CT17 (not original) CAT connector. It usually is composed by an USB plug (with some converter IC inside) and a 3.5mm jack for the radio connetion. Take care to this, infact 1) there are no USB port at the remoterig side and 2) the levels are not properly converted from/to the remoterig logic level.

So the solution is simply use a TTL-RS232 converter externally supplied. So I just buy a very pretty pcb here at Artekit Shop that it is supplied also within the enclosure (on request).

And I connected to the male 3.5mm jack directly using the RXD and the TXD pad:

  • the  TXD and RXD must be connected both to the central tip of the plug
  • and GND to the shaft of the plug

As power supply for the VCC and the GND of the board I used the 5V taken from a USB cable.

Of course the remoterig must be programmed accordly. These are the settings of RRC-CP.

COM2 mode
COM2 baudrate
COM2 data bits
COM2 stop bits
COM2 parity
COM2 terminator (hex)
Use USB Com Port as COM2

The COM2 is referred to the serial port in the remoterig device.

The last row of the options table indicates that you can connect the RRC-CP front USB port directly to your PC. On the PC you must select the corresponding COM port after installing the microbit serial driver. Usually the driver installs four virtual serial ports called RRC1258 COM0 COM1 COM2 COMEXTRA. Then simply locate the “RRC1258 COM2” to which COM on the PC is assigned and use that value.

In the program you use for control you just need to set this com port with 9600 8n1 speed (I tried it with a faster speed but it doesn’t seem so reliable and also not necessary), 88h is the default terminator code.

From the software side I tested with HRD deluxe, BBLogger, N1MM+, MTTY and some other software for digital mode without problem.

If you have any feedback, please feel free to send me.

My acknowledgement goes to Charlie KB8CR that suggested to me this approach.