Anyone with an ICOM IC-705 that knows how to connect the IC-705 CI-V interface to the Loftur Loop-Controller??

Robbert J. van Herksen

Hi there.

Just finished building my Loftur LoopController (using the new 2021 v12.02 PCB) plus the SWR Bridge v1.3 PCB.
I wanted to test it on my new ICOM IC-705.

Unfortunately, that didn't work out well....

I just found out that it is impossible to connect my IC-705 to the serial port on the Loop Controller (via the serial connector on the MLA Controller PCB)

Reason: The IC-705 does NOT have a (dedicated) CI-V connector !!! 


What I tried, is to cut off the USB-A connector of a Micro USB cable, and solder three of the four wires (Ground, TX and RX) of that USB cable to the 3 pin serial connector of the Loftur MLA controller board.

Didn't work !!

After reading on the internet, I found that ICOM IC-705 doesn't have a dedicated CI-V connector !!
It's can ONLY send/receive CI-V signals over a USB connection, using a PC !!!!

So, after learning about this, I found a Canadian amateur (VE2DX) that is selling multi-port Bluetooth connected CI-V units.
But it's quite unpractical as it gets it's Bluetooth connection via a BT dongle in a PC.
Also his pruduct, called CT-17B-6BT unit needs a sepate powersupply (via USB cable)

THat's is a bridge too far for me.

Of course there is a solution for it:
Connect a Raspberry Pi Zero to the IC-705 using a USB cable.
It will establish a true USB connection with the Raspberry Pi.

But now the most difficult part: I need a HAT (i.e. a small PCB that you click onto the Raspberry Pi) that has a REAL CI-V interface on it, that is talking to the Raspberry Pi, getting
the CI-V communications from the Raspberry Pi.

It sounds so simple, and I'm an electronics engineer, but I really could use some input from some seasoned hardware engineers that could help me out with this project.

Would be great to get input from you guys.

73 de Robbert / TA2IX (aka PA3BKL)
73 de Robbert / TA2IX (aka PA3BKL)
The dutch guy living in Istanbul


Hello Robbert,

I am Richard VE2DX been making CI-V interfaces for the IC-705 for couple of years now, the original CT17B-6BT is linked to the 705 via Bluetooth and then your CI-V devices have 5 ports for interconnectors.

the newly Dayton announced CT17B-7DM as Bluetooth, USB and 5 CI-V ports.

you can have more information at


Richard VE2DX