cab’s correct. Your voltage already appears to be stable so regulation isn’t going to improve your situation. There may be other anomalies, however, and you would have to address those before spending $$$$ on a PLC component.
I’ve had at least 8 different “power conditioners” and found their usefulness less than uniform. One issue that is unavoidable in your home is electrical noise generated within your home through appliances, computers, digital clocks, etc.
I have pretty stable mains where I live and in my experience an isolation transformer on my digital components yielded the best improvement and also at the lowest cost. You can find small isolation transformers (<3 or 4 amps for your digital gear) on Ebay for well under $100.00. Powervar makes some good units. If it doesn’t work as you expect, sell it and lose nothing. It beats spending 100s or 1000s on something that may offer the same improvement.
Before spending big bucks on a PLC, try an isolation transformer. And of course a dedicated circuit line should be the first step if possible.
