Using a USB hub for a single USB cable to your PC

Nigel G4ZAL has tweaked his ubitx so that he has an ‘all in one’ rig for FT8 and other digimodes, including CAT control (FT-817 emulation).

To achieve this, he added an un-powered 4 port USB hub inside the rig and used a cheap USB sound card (discarded casing shown to right side of the pics below).  He cut the USB cable and hard wired the USB hub from the back panel and into the Raduino via the USB hub.   He didn’t connect the USB 5v power into the Raduino).   He also hacked the USB sound card so he could wire it directly to the corresponding MIC and SPKR wiring (used an old PC CD-ROM audio cable).

He is using the latest firmware KD8CEC in the ubitx and now has CAT control and sound  over a single USB cable to his PC/laptop.

Using the hub, he can also upload new firmware without opening the case.

In response to a question as to whether isolating transformers are required, Nigel noted that he had built a couple of devices like this and never had any issues requiring isolation transformers (He has some, but he never fitted them as the mod worked fine as is).


He used a USB cable “Mini USB 5pin male to female with screw panel mount extension cable” from eBay.   Nigel’s was wired incorrectly as the colours did not match the USB standard.  He had to wire according to how the manufacturer had made it.  He cut the cable to suit and hard wired it to the USB hub removing the original connection.

The USB hub was made by Startech, but any hub that can fit inside your enclosure should work.  Nigel removed 2 of the USB sockets on the hub and hard wired the stripped down USB sound card.   He removed the USB connector and 3.5mm audio/mic sockets and soldered these connections direct to the hub.   He also added connector pins for the audio/mic (CD-ROM) cable.  He went to these extremes so that the hub and sound card would all fit inside his enclosure.  If your enclosure is larger they can all be simply plugged together.

The USB sound card can be found on the famous auction web site. Nigel’s was an “External Virtual USB 3D Sound Audio Card Adaptor Converter Mic/Speaker PC Laptop“.   Nigel hard wired the Raduino USB side of the connector to the hub as well, but he didn’t connect the 5v power line (the Raduino is powered as normal).

Reference

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