TinySA Spectrum Analyser

I really need to do something about nailing down my noise issues. 

I discovered this article - http://ka7oei.blogspot.com/2021/02/rfi-radio-frequency-interference.html and it uses a TinySA  - a small, low cost spectrum analyser that looks a lot like the NanoVNA, but most certainly isn't. 

 

Credit: eBay

 

Like a lot of new homes, we've got a heap of LED downlights, LED TVs, fridges, freezers and more cheap & nasty switch mode power supplies floating around than I can count. 

We also have aquariums - one with an LED light setup I built over a decade ago that uses an old Arduino board for PWM control to a set of Meanwell drivers. The other is a set of more modern, commercially built LEDs... that use a custom controller... for PWM control. That aquarium is also full of DC operating devices that have power bricks piled up with all manner of speed controllers that I have no doubt are also probably.. PWM. 

Then there's the 42RU rack on the wall opposite my study.. aka... shack.. full of IT gear, including a couple more switch mode power supplies that drive the two PCs I use for my radios. 

Let's not forget about the screens in my study that combined provide more real estate that many peoples family TVs. 

There's a point where doing the usual QRM hunting - toroids and ferrite clamp ons on everything near your radios where you realise all of those toroids and ferrites get really expensive really, really quickly. Once you get out of the shack, it really adds up.

I'd love to just put them on everything that could make noise, but then I could use that money to buy the IC-7300 I want, and I'd still have change. 

So, I think it's something that needs focus. I know that the tank lights cause some interference. I've heard them on the Malachit SDR, but it's not terribly focussed on what frequency and it's looking at a fairly narrow band.

Reading that article above, I've decided that the TinySA is a good, cheap investment. I already have a MiniWhip floating around doing nothing, so I can pair with that easily. 

My goal is quite simply to go over the whole house and see what is making noise and where that noise is specifically. Those that impact frequencies I care about will get attention. Those that don't will be ignored. 

In hindsight, I probably could just hook the MiniWhip up to the Malachit and go through band by band, but amongst other things, it has its own little birdy thanks to its own screen that can throw readings out. At least with a device that is actually a spectrum analyser, I know I'm more likely to be seeing something that is actually there and can look at a broader frequency range to see if anything is standing out so I can start with the worst offenders first.