Re: Taking a closer look at computer monitor RFI and a way to minimize it.


including noise near to DC

I just noticed your terminology.

That is not what I call the central spike. The central spike is a single needle right in the centre of the SDR display. Not confined to soundcard SDR but more usually noticed with soundcards. My understanding is that it is due to imbalance at the ADC input.

"noise near to DC " is not a spike but was often confused with my definition of "spike". It is many spikes due to noise starting each side of the central spike forming a mound. Changing grounding and audio cables may affect it.
But as you infer, keeping operation away from the central portion will have no effect on signals. Often it is of no real consequence but many users wanted to eliminate it, very few were content to just leave it.

Just trying to smooth over a misunderstanding which seems to have festered for years:-)

73 Alan G4ZFQ

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