Hi Roger

I don't fit your category, (understanding SL) however I often see this, noise from the mains I suspect, huge dirty sine waves. Considering they originate from a 50Hz source they are strongest at lower frequencies, rarely climbing above 6kHz but peaks sometimes get to 8.971kHz not much higher..

73 Eddie G3ZJO

On 07/04/2011 17:09, Roger Lapthorn wrote:

Help...

After lunch today my wife turned on the washing machine and the tumble drier and for two periods there was a burst of interference visible on the lower split screen as vertical noise stripes. What I don't understand is why I don't see these also on the upper trace around 8.976kHz too when the settings are the same.  I have a SL filter selected but it is centred around 8.970kHz with 400Hz width and slopes so this cannot explain this. Surely the noise bursts should appear in both parts of the screen?

Can someone who understands Spectrum Lab explain this please?

73s
Roger G3XBM

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