Computer Clock static interference

I have noticed that some times, on some bands, in FT8, I get an intermittent static sound, about every second, when using the Digirig. Its origin has stumped me for some time, until now.
Today, I was watching the progress bar in FT8 while it was “listening” on FT8 and I noted that the static repeating sound corresponded with each second count of the bottom right progress bar. Hmm. I tried to stretch the Digirig cables to see if a little distance could lessen the sound. It did not. Unplugging the Digirig immediately stopped it.
Do I need some kind of interference preventing device on my cables? A ferrite core? Any other suggestions?

Rod, where do you observe the static sound? Is it in your computer’s speakers?
How are they linked to the Digirig’s sound input or output?

The sound is coming from the radio speaker.

So this must be something picked up by the antenna.
Does it depend on the software running? When you hear the sound try shutting down all apps while keeping Digirig connected.

I shut down all apps on my MacBook pro except WSJTX. The static sound is still running to the beat of the progress bar and clock. Of course, I cannot turn off the clock in FT8. I tried the Hotpaw Audio FT8 Decoder App connected to the Digirig and the static is gone.
So the clock app, or WSJTX itself on my MBP must be generating some minor RF that is being picked up on the indoor Loop antenna I’m using, which is attached directly to the SO-259 socket on the back of the radio. It’s only 30cm away which is also an issue. I will be adding an attic antenna soon. Hopefully that will elevate the problem.
The next time I do POTA, I’ll be using my EF Random wire antenna, and see if this is replicated with that set up. Another test I will try is to connect a ground wire to the ground screw on the back of the radio. This may help.
I’m open to any and all suggestions! Appreciate your immediate attention to my query.


Here’s a short video link to the set up, with the sound when operating FT8 with the indoor loop antenna on the FT-818. Hope you can view this.

I have now discovered that the static is only heard on 20m and 17m in FT8