Audio Interface for my Ubitx

Here is how I built my Audio Interface for my Ubitx.

My audio interface for the UBitx

When I first tested WSJT-X with my Ubitx I connected the USB sound card directly to the MIC and AUDIO OUT connections of the UBitx. I noticed soon that the USB sound card got extremely hot. I did some research and found that its probably not a good idea to connect them directly due to currents flowing between the sound card and the Ubitx. I even read that some friends destroyed their Ubitx circuits that way.

My self-built interface does not have a PTT circuit since the Ubitx can be connected to a PC with USB providing the option to trigger the PTT through USB (at least with the firmware I am running, KD8CECs version of the firmware).

After some research I came up with a schematic like this:

The 600 Ohm transformers were ordered through Ebay. The remaining parts I had at home.

73 de Alfred.